[U-Boot] [PATCH 1/5 v2] dm: device_remove: Don't return in device_chld_remove() upon error
On my x86 platform I've noticed, that calling dm_uninit() or the new function dm_remove_devices_flags() does not remove the desired device at all. Debugging showed, that the serial uclass returns -EPERM in serial_pre_remove() and this leads to a complete stop of the device removal pretty early, as the serial device is one of the first ones in the DM. Here the dm tree output:
=> dm tree Class Probed Name ---------------------------------------- root [ + ] root_driver rsa_mod_exp [ ] |-- mod_exp_sw serial [ + ] |-- serial rtc [ ] |-- rtc timer [ + ] |-- tsc-timer syscon [ + ] |-- pch_pinctrl ...
In this example, device_remove(root) will stop directly after trying to remove the "serial" device.
To solve this problem, this patch removes the return upon error check in the device_remove() call in device_chld_remove(). This leads to device_chld_remove() continuing with the device_remove() call to the following child devices.
Signed-off-by: Stefan Roese sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com --- v2: - Add debug() output in error case
drivers/core/device-remove.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c index cc0043b990..a1c0103af0 100644 --- a/drivers/core/device-remove.c +++ b/drivers/core/device-remove.c @@ -58,8 +58,14 @@ static int device_chld_remove(struct udevice *dev, uint flags)
list_for_each_entry_safe(pos, n, &dev->child_head, sibling_node) { ret = device_remove(pos, flags); - if (ret) - return ret; + /* + * Don't stop on error here, the remaining child devices still + * need to get removed. + */ + if (ret) { + debug("%s: device_remove(%s) returned %d\n", + __func__, pos->name, ret); + } }
return 0;
On my x86 platform I've noticed, that calling dm_uninit() or the new function dm_remove_devices_flags() does not remove the desired device at all. Debugging showed, that the serial uclass returns -EPERM in serial_pre_remove(). This patch sets the force parameter when calling stdio_deregister_dev() resulting in a removal of the device.
Signed-off-by: Stefan Roese sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com --- v2: - New patch
drivers/serial/serial-uclass.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c index 43c028ebe6..c2b9c5f12f 100644 --- a/drivers/serial/serial-uclass.c +++ b/drivers/serial/serial-uclass.c @@ -349,7 +349,7 @@ static int serial_pre_remove(struct udevice *dev) #if CONFIG_IS_ENABLED(SYS_STDIO_DEREGISTER) struct serial_dev_priv *upriv = dev_get_uclass_priv(dev);
- if (stdio_deregister_dev(upriv->sdev, 0)) + if (stdio_deregister_dev(upriv->sdev, true)) return -EPERM; #endif
On 24 April 2017 at 01:48, Stefan Roese sr@denx.de wrote:
On my x86 platform I've noticed, that calling dm_uninit() or the new function dm_remove_devices_flags() does not remove the desired device at all. Debugging showed, that the serial uclass returns -EPERM in serial_pre_remove(). This patch sets the force parameter when calling stdio_deregister_dev() resulting in a removal of the device.
Signed-off-by: Stefan Roese sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com
v2:
- New patch
drivers/serial/serial-uclass.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Simon Glass sjg@chromium.org
On Sat, Apr 29, 2017 at 8:26 AM, Simon Glass sjg@chromium.org wrote:
On 24 April 2017 at 01:48, Stefan Roese sr@denx.de wrote:
On my x86 platform I've noticed, that calling dm_uninit() or the new function dm_remove_devices_flags() does not remove the desired device at all. Debugging showed, that the serial uclass returns -EPERM in serial_pre_remove(). This patch sets the force parameter when calling stdio_deregister_dev() resulting in a removal of the device.
Signed-off-by: Stefan Roese sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com
v2:
- New patch
drivers/serial/serial-uclass.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Simon Glass sjg@chromium.org
applied to u-boot-x86, thanks!
This new flag can be added to DM device drivers, which need to do some final configuration before U-Boot exits and the OS (e.g. Linux) is started. The remove functions of those drivers will get called at this stage to do these last-stage configuration steps.
Signed-off-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com --- - Renamed flag to DM_FLAG_OS_PREPARE
drivers/core/device-remove.c | 16 +++++++++++----- include/dm/device.h | 11 ++++++++++- 2 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c index a1c0103af0..1ea2b0ae00 100644 --- a/drivers/core/device-remove.c +++ b/drivers/core/device-remove.c @@ -158,6 +158,15 @@ void device_free(struct udevice *dev) devres_release_probe(dev); }
+static bool flags_remove(uint flags, uint drv_flags) +{ + if ((flags & DM_REMOVE_NORMAL) || + (flags & (drv_flags & (DM_FLAG_ACTIVE_DMA | DM_FLAG_OS_PREPARE)))) + return true; + + return false; +} + int device_remove(struct udevice *dev, uint flags) { const struct driver *drv; @@ -184,9 +193,7 @@ int device_remove(struct udevice *dev, uint flags) * Remove the device if called with the "normal" remove flag set, * or if the remove flag matches any of the drivers remove flags */ - if (drv->remove && - ((flags & DM_REMOVE_NORMAL) || - (flags & (drv->flags & DM_FLAG_ACTIVE_DMA)))) { + if (drv->remove && flags_remove(flags, drv->flags)) { ret = drv->remove(dev); if (ret) goto err_remove; @@ -200,8 +207,7 @@ int device_remove(struct udevice *dev, uint flags) } }
- if ((flags & DM_REMOVE_NORMAL) || - (flags & (drv->flags & DM_FLAG_ACTIVE_DMA))) { + if (flags_remove(flags, drv->flags)) { device_free(dev);
dev->seq = -1; diff --git a/include/dm/device.h b/include/dm/device.h index 079ec57003..df02e41df3 100644 --- a/include/dm/device.h +++ b/include/dm/device.h @@ -55,6 +55,12 @@ struct driver_info; #define DM_FLAG_ACTIVE_DMA (1 << 9)
/* + * Call driver remove function to do some final configuration, before + * U-Boot exits and the OS is started + */ +#define DM_FLAG_OS_PREPARE (1 << 10) + +/* * One or multiple of these flags are passed to device_remove() so that * a selective device removal as specified by the remove-stage and the * driver flags can be done. @@ -66,10 +72,13 @@ enum { /* Remove devices with active DMA */ DM_REMOVE_ACTIVE_DMA = DM_FLAG_ACTIVE_DMA,
+ /* Remove devices which need some final OS preparation steps */ + DM_REMOVE_OS_PREPARE = DM_FLAG_OS_PREPARE, + /* Add more use cases here */
/* Remove devices with any active flag */ - DM_REMOVE_ACTIVE_ALL = DM_REMOVE_ACTIVE_DMA, + DM_REMOVE_ACTIVE_ALL = DM_REMOVE_ACTIVE_DMA | DM_REMOVE_OS_PREPARE, };
/**
On Mon, Apr 24, 2017 at 3:48 PM, Stefan Roese sr@denx.de wrote:
This new flag can be added to DM device drivers, which need to do some final configuration before U-Boot exits and the OS (e.g. Linux) is started. The remove functions of those drivers will get called at this stage to do these last-stage configuration steps.
Signed-off-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com
- Renamed flag to DM_FLAG_OS_PREPARE
drivers/core/device-remove.c | 16 +++++++++++----- include/dm/device.h | 11 ++++++++++- 2 files changed, 21 insertions(+), 6 deletions(-)
applied to u-boot-x86, thanks!
This patch adds a call to dm_remove_devices_flags() to bootm_announce_and_cleanup() so that drivers that have one of the removal flags set (e.g. DM_FLAG_ACTIVE_DMA_REMOVE) in their driver struct, may do some last-stage cleanup before the OS is started.
Signed-off-by: Stefan Roese sr@denx.de Cc: Bin Meng bmeng.cn@gmail.com Reviewed-by: Simon Glass sjg@chromium.org --- v2: - Added Simons RB line
arch/x86/lib/bootm.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/arch/x86/lib/bootm.c b/arch/x86/lib/bootm.c index 75bab90225..ecd4f4e6c6 100644 --- a/arch/x86/lib/bootm.c +++ b/arch/x86/lib/bootm.c @@ -10,6 +10,8 @@
#include <common.h> #include <command.h> +#include <dm/device.h> +#include <dm/root.h> #include <errno.h> #include <fdt_support.h> #include <image.h> @@ -46,6 +48,13 @@ void bootm_announce_and_cleanup(void) #ifdef CONFIG_BOOTSTAGE_REPORT bootstage_report(); #endif + + /* + * Call remove function of all devices with a removal flag set. + * This may be useful for last-stage operations, like cancelling + * of DMA operation or releasing device internal buffers. + */ + dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL); }
#if defined(CONFIG_OF_LIBFDT) && !defined(CONFIG_OF_NO_KERNEL)
On Mon, Apr 24, 2017 at 3:48 PM, Stefan Roese sr@denx.de wrote:
This patch adds a call to dm_remove_devices_flags() to bootm_announce_and_cleanup() so that drivers that have one of the removal flags set (e.g. DM_FLAG_ACTIVE_DMA_REMOVE) in their driver struct, may do some last-stage cleanup before the OS is started.
Signed-off-by: Stefan Roese sr@denx.de Cc: Bin Meng bmeng.cn@gmail.com Reviewed-by: Simon Glass sjg@chromium.org
v2:
- Added Simons RB line
arch/x86/lib/bootm.c | 9 +++++++++ 1 file changed, 9 insertions(+)
applied to u-boot-x86, thanks!
This patch adds a remove function to the Intel ICH SPI driver, that will be called upon U-Boot exit, directly before the OS (Linux) is started. This function takes care of configuring the BIOS registers in the SPI controller (similar to what a "standard" BIOS or coreboot does), so that the Linux MTD device driver is able to correctly read/write to the SPI NOR chip. Without this, the chip is not detected at all.
Signed-off-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com Cc: Jagan Teki jteki@openedev.com --- v2: - Added Simons RB line
drivers/spi/ich.c | 18 ++++++++++++++++++ drivers/spi/ich.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 65 insertions(+), 7 deletions(-)
diff --git a/drivers/spi/ich.c b/drivers/spi/ich.c index 893fe33b66..bf2e99b5cc 100644 --- a/drivers/spi/ich.c +++ b/drivers/spi/ich.c @@ -617,6 +617,22 @@ static int ich_spi_probe(struct udevice *dev) return 0; }
+static int ich_spi_remove(struct udevice *bus) +{ + struct ich_spi_priv *ctlr = dev_get_priv(bus); + + /* + * Configure SPI controller so that the Linux MTD driver can fully + * access the SPI NOR chip + */ + ich_writew(ctlr, SPI_OPPREFIX, ctlr->preop); + ich_writew(ctlr, SPI_OPTYPE, ctlr->optype); + ich_writel(ctlr, SPI_OPMENU_LOWER, ctlr->opmenu); + ich_writel(ctlr, SPI_OPMENU_UPPER, ctlr->opmenu + sizeof(u32)); + + return 0; +} + static int ich_spi_set_speed(struct udevice *bus, uint speed) { struct ich_spi_priv *priv = dev_get_priv(bus); @@ -700,4 +716,6 @@ U_BOOT_DRIVER(ich_spi) = { .priv_auto_alloc_size = sizeof(struct ich_spi_priv), .child_pre_probe = ich_spi_child_pre_probe, .probe = ich_spi_probe, + .remove = ich_spi_remove, + .flags = DM_FLAG_OS_PREPARE, }; diff --git a/drivers/spi/ich.h b/drivers/spi/ich.h index bd0a820809..dcb8a9048f 100644 --- a/drivers/spi/ich.h +++ b/drivers/spi/ich.h @@ -102,13 +102,6 @@ enum { };
enum { - SPI_OPCODE_TYPE_READ_NO_ADDRESS = 0, - SPI_OPCODE_TYPE_WRITE_NO_ADDRESS = 1, - SPI_OPCODE_TYPE_READ_WITH_ADDRESS = 2, - SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS = 3 -}; - -enum { ICH_MAX_CMD_LEN = 5, };
@@ -124,8 +117,55 @@ struct spi_trans { uint32_t offset; };
+#define SPI_OPCODE_WRSR 0x01 +#define SPI_OPCODE_PAGE_PROGRAM 0x02 +#define SPI_OPCODE_READ 0x03 +#define SPI_OPCODE_WRDIS 0x04 +#define SPI_OPCODE_RDSR 0x05 #define SPI_OPCODE_WREN 0x06 #define SPI_OPCODE_FAST_READ 0x0b +#define SPI_OPCODE_ERASE_SECT 0x20 +#define SPI_OPCODE_READ_ID 0x9f +#define SPI_OPCODE_ERASE_BLOCK 0xd8 + +#define SPI_OPCODE_TYPE_READ_NO_ADDRESS 0 +#define SPI_OPCODE_TYPE_WRITE_NO_ADDRESS 1 +#define SPI_OPCODE_TYPE_READ_WITH_ADDRESS 2 +#define SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS 3 + +#define SPI_OPMENU_0 SPI_OPCODE_WRSR +#define SPI_OPTYPE_0 SPI_OPCODE_TYPE_WRITE_NO_ADDRESS + +#define SPI_OPMENU_1 SPI_OPCODE_PAGE_PROGRAM +#define SPI_OPTYPE_1 SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS + +#define SPI_OPMENU_2 SPI_OPCODE_READ +#define SPI_OPTYPE_2 SPI_OPCODE_TYPE_READ_WITH_ADDRESS + +#define SPI_OPMENU_3 SPI_OPCODE_RDSR +#define SPI_OPTYPE_3 SPI_OPCODE_TYPE_READ_NO_ADDRESS + +#define SPI_OPMENU_4 SPI_OPCODE_ERASE_SECT +#define SPI_OPTYPE_4 SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS + +#define SPI_OPMENU_5 SPI_OPCODE_READ_ID +#define SPI_OPTYPE_5 SPI_OPCODE_TYPE_READ_NO_ADDRESS + +#define SPI_OPMENU_6 SPI_OPCODE_ERASE_BLOCK +#define SPI_OPTYPE_6 SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS + +#define SPI_OPMENU_7 SPI_OPCODE_FAST_READ +#define SPI_OPTYPE_7 SPI_OPCODE_TYPE_READ_WITH_ADDRESS + +#define SPI_OPPREFIX ((SPI_OPCODE_WREN << 8) | SPI_OPCODE_WREN) +#define SPI_OPTYPE ((SPI_OPTYPE_7 << 14) | (SPI_OPTYPE_6 << 12) | \ + (SPI_OPTYPE_5 << 10) | (SPI_OPTYPE_4 << 8) | \ + (SPI_OPTYPE_3 << 6) | (SPI_OPTYPE_2 << 4) | \ + (SPI_OPTYPE_1 << 2) | (SPI_OPTYPE_0 << 0)) +#define SPI_OPMENU_UPPER ((SPI_OPMENU_7 << 24) | (SPI_OPMENU_6 << 16) | \ + (SPI_OPMENU_5 << 8) | (SPI_OPMENU_4 << 0)) +#define SPI_OPMENU_LOWER ((SPI_OPMENU_3 << 24) | (SPI_OPMENU_2 << 16) | \ + (SPI_OPMENU_1 << 8) | (SPI_OPMENU_0 << 0))
enum ich_version { ICHV_7,
On Mon, Apr 24, 2017 at 3:48 PM, Stefan Roese sr@denx.de wrote:
This patch adds a remove function to the Intel ICH SPI driver, that will be called upon U-Boot exit, directly before the OS (Linux) is started. This function takes care of configuring the BIOS registers in the SPI controller (similar to what a "standard" BIOS or coreboot does), so that the Linux MTD device driver is able to correctly read/write to the SPI NOR chip. Without this, the chip is not detected at all.
Signed-off-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com Cc: Jagan Teki jteki@openedev.com
v2:
- Added Simons RB line
drivers/spi/ich.c | 18 ++++++++++++++++++ drivers/spi/ich.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 65 insertions(+), 7 deletions(-)
applied to u-boot-x86, thanks!
On Mon, Apr 24, 2017 at 1:18 PM, Stefan Roese sr@denx.de wrote:
This patch adds a remove function to the Intel ICH SPI driver, that will be called upon U-Boot exit, directly before the OS (Linux) is started. This function takes care of configuring the BIOS registers in the SPI controller (similar to what a "standard" BIOS or coreboot does), so that the Linux MTD device driver is able to correctly read/write to the SPI NOR chip. Without this, the chip is not detected at all.
Signed-off-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com Cc: Jagan Teki jteki@openedev.com
v2:
- Added Simons RB line
drivers/spi/ich.c | 18 ++++++++++++++++++ drivers/spi/ich.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 65 insertions(+), 7 deletions(-)
diff --git a/drivers/spi/ich.c b/drivers/spi/ich.c index 893fe33b66..bf2e99b5cc 100644 --- a/drivers/spi/ich.c +++ b/drivers/spi/ich.c @@ -617,6 +617,22 @@ static int ich_spi_probe(struct udevice *dev) return 0; }
+static int ich_spi_remove(struct udevice *bus) +{
struct ich_spi_priv *ctlr = dev_get_priv(bus);/** Configure SPI controller so that the Linux MTD driver can fully* access the SPI NOR chip*/ich_writew(ctlr, SPI_OPPREFIX, ctlr->preop);ich_writew(ctlr, SPI_OPTYPE, ctlr->optype);ich_writel(ctlr, SPI_OPMENU_LOWER, ctlr->opmenu);ich_writel(ctlr, SPI_OPMENU_UPPER, ctlr->opmenu + sizeof(u32));return 0;+}
static int ich_spi_set_speed(struct udevice *bus, uint speed) { struct ich_spi_priv *priv = dev_get_priv(bus); @@ -700,4 +716,6 @@ U_BOOT_DRIVER(ich_spi) = { .priv_auto_alloc_size = sizeof(struct ich_spi_priv), .child_pre_probe = ich_spi_child_pre_probe, .probe = ich_spi_probe,
.remove = ich_spi_remove,.flags = DM_FLAG_OS_PREPARE,}; diff --git a/drivers/spi/ich.h b/drivers/spi/ich.h index bd0a820809..dcb8a9048f 100644 --- a/drivers/spi/ich.h +++ b/drivers/spi/ich.h @@ -102,13 +102,6 @@ enum { };
enum {
SPI_OPCODE_TYPE_READ_NO_ADDRESS = 0,SPI_OPCODE_TYPE_WRITE_NO_ADDRESS = 1,SPI_OPCODE_TYPE_READ_WITH_ADDRESS = 2,SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS = 3-};
-enum { ICH_MAX_CMD_LEN = 5, };
@@ -124,8 +117,55 @@ struct spi_trans { uint32_t offset; };
+#define SPI_OPCODE_WRSR 0x01 +#define SPI_OPCODE_PAGE_PROGRAM 0x02 +#define SPI_OPCODE_READ 0x03 +#define SPI_OPCODE_WRDIS 0x04 +#define SPI_OPCODE_RDSR 0x05 #define SPI_OPCODE_WREN 0x06 #define SPI_OPCODE_FAST_READ 0x0b +#define SPI_OPCODE_ERASE_SECT 0x20 +#define SPI_OPCODE_READ_ID 0x9f +#define SPI_OPCODE_ERASE_BLOCK 0xd8
Wonder why the flash part should be part of SPI, can't we use existing spi_flash through command interface if there is specific stuff like this?
Same I've commented on previous version, no response either but applied?
thanks!
(Added Simon to Cc)
On 09.05.2017 13:14, Jagan Teki wrote:
On Mon, Apr 24, 2017 at 1:18 PM, Stefan Roese sr@denx.de wrote:
This patch adds a remove function to the Intel ICH SPI driver, that will be called upon U-Boot exit, directly before the OS (Linux) is started. This function takes care of configuring the BIOS registers in the SPI controller (similar to what a "standard" BIOS or coreboot does), so that the Linux MTD device driver is able to correctly read/write to the SPI NOR chip. Without this, the chip is not detected at all.
Signed-off-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com Cc: Jagan Teki jteki@openedev.com
v2:
- Added Simons RB line
drivers/spi/ich.c | 18 ++++++++++++++++++ drivers/spi/ich.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 65 insertions(+), 7 deletions(-)
diff --git a/drivers/spi/ich.c b/drivers/spi/ich.c index 893fe33b66..bf2e99b5cc 100644 --- a/drivers/spi/ich.c +++ b/drivers/spi/ich.c @@ -617,6 +617,22 @@ static int ich_spi_probe(struct udevice *dev) return 0; }
+static int ich_spi_remove(struct udevice *bus) +{
struct ich_spi_priv *ctlr = dev_get_priv(bus);/** Configure SPI controller so that the Linux MTD driver can fully* access the SPI NOR chip*/ich_writew(ctlr, SPI_OPPREFIX, ctlr->preop);ich_writew(ctlr, SPI_OPTYPE, ctlr->optype);ich_writel(ctlr, SPI_OPMENU_LOWER, ctlr->opmenu);ich_writel(ctlr, SPI_OPMENU_UPPER, ctlr->opmenu + sizeof(u32));return 0;+}
static int ich_spi_set_speed(struct udevice *bus, uint speed) { struct ich_spi_priv *priv = dev_get_priv(bus); @@ -700,4 +716,6 @@ U_BOOT_DRIVER(ich_spi) = { .priv_auto_alloc_size = sizeof(struct ich_spi_priv), .child_pre_probe = ich_spi_child_pre_probe, .probe = ich_spi_probe,
.remove = ich_spi_remove,.flags = DM_FLAG_OS_PREPARE,}; diff --git a/drivers/spi/ich.h b/drivers/spi/ich.h index bd0a820809..dcb8a9048f 100644 --- a/drivers/spi/ich.h +++ b/drivers/spi/ich.h @@ -102,13 +102,6 @@ enum { };
enum {
SPI_OPCODE_TYPE_READ_NO_ADDRESS = 0,SPI_OPCODE_TYPE_WRITE_NO_ADDRESS = 1,SPI_OPCODE_TYPE_READ_WITH_ADDRESS = 2,SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS = 3-};
-enum { ICH_MAX_CMD_LEN = 5, };
@@ -124,8 +117,55 @@ struct spi_trans { uint32_t offset; };
+#define SPI_OPCODE_WRSR 0x01 +#define SPI_OPCODE_PAGE_PROGRAM 0x02 +#define SPI_OPCODE_READ 0x03 +#define SPI_OPCODE_WRDIS 0x04 +#define SPI_OPCODE_RDSR 0x05 #define SPI_OPCODE_WREN 0x06 #define SPI_OPCODE_FAST_READ 0x0b +#define SPI_OPCODE_ERASE_SECT 0x20 +#define SPI_OPCODE_READ_ID 0x9f +#define SPI_OPCODE_ERASE_BLOCK 0xd8
Wonder why the flash part should be part of SPI, can't we use existing spi_flash through command interface if there is specific stuff like this?
This patch only changes some defines here and passes some allowed opcodes via some configuration registers to the Linux driver.
I didn't look closely into this U-Boot driver and how it interacts with the SPI NOR. Simon is most likely the best person to answer on your questions regarding the usage of spi_flash. Simon could you please answer Jagan's questions?
Thanks, Stefan
On Tue, May 9, 2017 at 7:20 PM, Stefan Roese sr@denx.de wrote:
(Added Simon to Cc)
Really added Simon :-)
On 09.05.2017 13:14, Jagan Teki wrote:
On Mon, Apr 24, 2017 at 1:18 PM, Stefan Roese sr@denx.de wrote:
This patch adds a remove function to the Intel ICH SPI driver, that will be called upon U-Boot exit, directly before the OS (Linux) is started. This function takes care of configuring the BIOS registers in the SPI controller (similar to what a "standard" BIOS or coreboot does), so that the Linux MTD device driver is able to correctly read/write to the SPI NOR chip. Without this, the chip is not detected at all.
Signed-off-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com Cc: Jagan Teki jteki@openedev.com
v2:
- Added Simons RB line
drivers/spi/ich.c | 18 ++++++++++++++++++ drivers/spi/ich.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 65 insertions(+), 7 deletions(-)
diff --git a/drivers/spi/ich.c b/drivers/spi/ich.c index 893fe33b66..bf2e99b5cc 100644 --- a/drivers/spi/ich.c +++ b/drivers/spi/ich.c @@ -617,6 +617,22 @@ static int ich_spi_probe(struct udevice *dev) return 0; }
+static int ich_spi_remove(struct udevice *bus) +{
struct ich_spi_priv *ctlr = dev_get_priv(bus);/** Configure SPI controller so that the Linux MTD driver canfully
* access the SPI NOR chip*/ich_writew(ctlr, SPI_OPPREFIX, ctlr->preop);ich_writew(ctlr, SPI_OPTYPE, ctlr->optype);ich_writel(ctlr, SPI_OPMENU_LOWER, ctlr->opmenu);ich_writel(ctlr, SPI_OPMENU_UPPER, ctlr->opmenu + sizeof(u32));return 0;+}
static int ich_spi_set_speed(struct udevice *bus, uint speed) { struct ich_spi_priv *priv = dev_get_priv(bus); @@ -700,4 +716,6 @@ U_BOOT_DRIVER(ich_spi) = { .priv_auto_alloc_size = sizeof(struct ich_spi_priv), .child_pre_probe = ich_spi_child_pre_probe, .probe = ich_spi_probe,
.remove = ich_spi_remove,.flags = DM_FLAG_OS_PREPARE,}; diff --git a/drivers/spi/ich.h b/drivers/spi/ich.h index bd0a820809..dcb8a9048f 100644 --- a/drivers/spi/ich.h +++ b/drivers/spi/ich.h @@ -102,13 +102,6 @@ enum { };
enum {
SPI_OPCODE_TYPE_READ_NO_ADDRESS = 0,SPI_OPCODE_TYPE_WRITE_NO_ADDRESS = 1,SPI_OPCODE_TYPE_READ_WITH_ADDRESS = 2,SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS = 3-};
-enum { ICH_MAX_CMD_LEN = 5, };
@@ -124,8 +117,55 @@ struct spi_trans { uint32_t offset; };
+#define SPI_OPCODE_WRSR 0x01 +#define SPI_OPCODE_PAGE_PROGRAM 0x02 +#define SPI_OPCODE_READ 0x03 +#define SPI_OPCODE_WRDIS 0x04 +#define SPI_OPCODE_RDSR 0x05 #define SPI_OPCODE_WREN 0x06 #define SPI_OPCODE_FAST_READ 0x0b +#define SPI_OPCODE_ERASE_SECT 0x20 +#define SPI_OPCODE_READ_ID 0x9f +#define SPI_OPCODE_ERASE_BLOCK 0xd8
Wonder why the flash part should be part of SPI, can't we use existing spi_flash through command interface if there is specific stuff like this?
These flash commands need to be programmed to SPI controller register, by Intel's design, to make Linux MTD driver happy. Possibly we may do like this, like get such value dynamically from spi_flash to program this to SPI controller? I once asked a question about this: if some other flash part that does not have the exact same command set as what was programmed to the SPI controller, will Linux MTD driver still work?
This patch only changes some defines here and passes some allowed opcodes via some configuration registers to the Linux driver.
I didn't look closely into this U-Boot driver and how it interacts with the SPI NOR. Simon is most likely the best person to answer on your questions regarding the usage of spi_flash. Simon could you please answer Jagan's questions?
Regards, Bin
Hi Bin,
On 10.05.2017 02:47, Bin Meng wrote:
On Tue, May 9, 2017 at 7:20 PM, Stefan Roese sr@denx.de wrote:
(Added Simon to Cc)
Really added Simon :-)
I did in my mail as well. Sometimes the ML removes recipients from the list as it seems.
On 09.05.2017 13:14, Jagan Teki wrote:
On Mon, Apr 24, 2017 at 1:18 PM, Stefan Roese sr@denx.de wrote:
This patch adds a remove function to the Intel ICH SPI driver, that will be called upon U-Boot exit, directly before the OS (Linux) is started. This function takes care of configuring the BIOS registers in the SPI controller (similar to what a "standard" BIOS or coreboot does), so that the Linux MTD device driver is able to correctly read/write to the SPI NOR chip. Without this, the chip is not detected at all.
Signed-off-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com Cc: Jagan Teki jteki@openedev.com
v2:
- Added Simons RB line
drivers/spi/ich.c | 18 ++++++++++++++++++ drivers/spi/ich.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 65 insertions(+), 7 deletions(-)
diff --git a/drivers/spi/ich.c b/drivers/spi/ich.c index 893fe33b66..bf2e99b5cc 100644 --- a/drivers/spi/ich.c +++ b/drivers/spi/ich.c @@ -617,6 +617,22 @@ static int ich_spi_probe(struct udevice *dev) return 0; }
+static int ich_spi_remove(struct udevice *bus) +{
struct ich_spi_priv *ctlr = dev_get_priv(bus);/** Configure SPI controller so that the Linux MTD driver canfully
* access the SPI NOR chip*/ich_writew(ctlr, SPI_OPPREFIX, ctlr->preop);ich_writew(ctlr, SPI_OPTYPE, ctlr->optype);ich_writel(ctlr, SPI_OPMENU_LOWER, ctlr->opmenu);ich_writel(ctlr, SPI_OPMENU_UPPER, ctlr->opmenu + sizeof(u32));return 0;+}
static int ich_spi_set_speed(struct udevice *bus, uint speed) { struct ich_spi_priv *priv = dev_get_priv(bus); @@ -700,4 +716,6 @@ U_BOOT_DRIVER(ich_spi) = { .priv_auto_alloc_size = sizeof(struct ich_spi_priv), .child_pre_probe = ich_spi_child_pre_probe, .probe = ich_spi_probe,
.remove = ich_spi_remove,.flags = DM_FLAG_OS_PREPARE,}; diff --git a/drivers/spi/ich.h b/drivers/spi/ich.h index bd0a820809..dcb8a9048f 100644 --- a/drivers/spi/ich.h +++ b/drivers/spi/ich.h @@ -102,13 +102,6 @@ enum { };
enum {
SPI_OPCODE_TYPE_READ_NO_ADDRESS = 0,SPI_OPCODE_TYPE_WRITE_NO_ADDRESS = 1,SPI_OPCODE_TYPE_READ_WITH_ADDRESS = 2,SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS = 3-};
-enum { ICH_MAX_CMD_LEN = 5, };
@@ -124,8 +117,55 @@ struct spi_trans { uint32_t offset; };
+#define SPI_OPCODE_WRSR 0x01 +#define SPI_OPCODE_PAGE_PROGRAM 0x02 +#define SPI_OPCODE_READ 0x03 +#define SPI_OPCODE_WRDIS 0x04 +#define SPI_OPCODE_RDSR 0x05 #define SPI_OPCODE_WREN 0x06 #define SPI_OPCODE_FAST_READ 0x0b +#define SPI_OPCODE_ERASE_SECT 0x20 +#define SPI_OPCODE_READ_ID 0x9f +#define SPI_OPCODE_ERASE_BLOCK 0xd8
Wonder why the flash part should be part of SPI, can't we use existing spi_flash through command interface if there is specific stuff like this?
These flash commands need to be programmed to SPI controller register, by Intel's design, to make Linux MTD driver happy. Possibly we may do like this, like get such value dynamically from spi_flash to program this to SPI controller? I once asked a question about this: if some other flash part that does not have the exact same command set as what was programmed to the SPI controller, will Linux MTD driver still work?
Yes, we discussed this a few months before already. I've not seen any other values used in coreboot - so these values seem to be quite "safe" for now. Once we have such an issue with incompatible SPI NOR chips on x86, we will find a way to solve this in a board specific way. But for now, its very helpful to have access from the Linux MTD subsystem to the NOR chips by using these patches.
Thanks, Stefan
Hi Jagan,
On 9 May 2017 at 18:47, Bin Meng bmeng.cn@gmail.com wrote:
On Tue, May 9, 2017 at 7:20 PM, Stefan Roese sr@denx.de wrote:
(Added Simon to Cc)
Really added Simon :-)
On 09.05.2017 13:14, Jagan Teki wrote:
On Mon, Apr 24, 2017 at 1:18 PM, Stefan Roese sr@denx.de wrote:
This patch adds a remove function to the Intel ICH SPI driver, that will be called upon U-Boot exit, directly before the OS (Linux) is started. This function takes care of configuring the BIOS registers in the SPI controller (similar to what a "standard" BIOS or coreboot does), so that the Linux MTD device driver is able to correctly read/write to the SPI NOR chip. Without this, the chip is not detected at all.
Signed-off-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com Cc: Jagan Teki jteki@openedev.com
v2:
- Added Simons RB line
drivers/spi/ich.c | 18 ++++++++++++++++++ drivers/spi/ich.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 65 insertions(+), 7 deletions(-)
diff --git a/drivers/spi/ich.c b/drivers/spi/ich.c index 893fe33b66..bf2e99b5cc 100644 --- a/drivers/spi/ich.c +++ b/drivers/spi/ich.c @@ -617,6 +617,22 @@ static int ich_spi_probe(struct udevice *dev) return 0; }
+static int ich_spi_remove(struct udevice *bus) +{
struct ich_spi_priv *ctlr = dev_get_priv(bus);/** Configure SPI controller so that the Linux MTD driver canfully
* access the SPI NOR chip*/ich_writew(ctlr, SPI_OPPREFIX, ctlr->preop);ich_writew(ctlr, SPI_OPTYPE, ctlr->optype);ich_writel(ctlr, SPI_OPMENU_LOWER, ctlr->opmenu);ich_writel(ctlr, SPI_OPMENU_UPPER, ctlr->opmenu + sizeof(u32));return 0;+}
static int ich_spi_set_speed(struct udevice *bus, uint speed) { struct ich_spi_priv *priv = dev_get_priv(bus); @@ -700,4 +716,6 @@ U_BOOT_DRIVER(ich_spi) = { .priv_auto_alloc_size = sizeof(struct ich_spi_priv), .child_pre_probe = ich_spi_child_pre_probe, .probe = ich_spi_probe,
.remove = ich_spi_remove,.flags = DM_FLAG_OS_PREPARE,}; diff --git a/drivers/spi/ich.h b/drivers/spi/ich.h index bd0a820809..dcb8a9048f 100644 --- a/drivers/spi/ich.h +++ b/drivers/spi/ich.h @@ -102,13 +102,6 @@ enum { };
enum {
SPI_OPCODE_TYPE_READ_NO_ADDRESS = 0,SPI_OPCODE_TYPE_WRITE_NO_ADDRESS = 1,SPI_OPCODE_TYPE_READ_WITH_ADDRESS = 2,SPI_OPCODE_TYPE_WRITE_WITH_ADDRESS = 3-};
-enum { ICH_MAX_CMD_LEN = 5, };
@@ -124,8 +117,55 @@ struct spi_trans { uint32_t offset; };
+#define SPI_OPCODE_WRSR 0x01 +#define SPI_OPCODE_PAGE_PROGRAM 0x02 +#define SPI_OPCODE_READ 0x03 +#define SPI_OPCODE_WRDIS 0x04 +#define SPI_OPCODE_RDSR 0x05 #define SPI_OPCODE_WREN 0x06 #define SPI_OPCODE_FAST_READ 0x0b +#define SPI_OPCODE_ERASE_SECT 0x20 +#define SPI_OPCODE_READ_ID 0x9f +#define SPI_OPCODE_ERASE_BLOCK 0xd8
Wonder why the flash part should be part of SPI, can't we use existing spi_flash through command interface if there is specific stuff like this?
This driver is odd in that it tries to decode low-level SPI requests coming in via spi_xfer() and issue high-level (SPI flash) commands to the controller. The controller does not actually support generic SPI operation.
These flash commands need to be programmed to SPI controller register, by Intel's design, to make Linux MTD driver happy. Possibly we may do like this, like get such value dynamically from spi_flash to program this to SPI controller? I once asked a question about this: if some other flash part that does not have the exact same command set as what was programmed to the SPI controller, will Linux MTD driver still work?
This patch only changes some defines here and passes some allowed opcodes via some configuration registers to the Linux driver.
I didn't look closely into this U-Boot driver and how it interacts with the SPI NOR. Simon is most likely the best person to answer on your questions regarding the usage of spi_flash. Simon could you please answer Jagan's questions?
Regards, Bin
Regards, Simon
Hi Stefan,
On 24 April 2017 at 01:48, Stefan Roese sr@denx.de wrote:
On my x86 platform I've noticed, that calling dm_uninit() or the new function dm_remove_devices_flags() does not remove the desired device at all. Debugging showed, that the serial uclass returns -EPERM in serial_pre_remove() and this leads to a complete stop of the device removal pretty early, as the serial device is one of the first ones in the DM. Here the dm tree output:
=> dm tree Class Probed Name
root [ + ] root_driver rsa_mod_exp [ ] |-- mod_exp_sw serial [ + ] |-- serial rtc [ ] |-- rtc timer [ + ] |-- tsc-timer syscon [ + ] |-- pch_pinctrl ...
In this example, device_remove(root) will stop directly after trying to remove the "serial" device.
To solve this problem, this patch removes the return upon error check in the device_remove() call in device_chld_remove(). This leads to device_chld_remove() continuing with the device_remove() call to the following child devices.
Signed-off-by: Stefan Roese sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com
v2:
- Add debug() output in error case
drivers/core/device-remove.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
I thought that your change to force removal of the stdio dev would make this change unnecessary?
I really would rather fix the root cause if we can.
diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c index cc0043b990..a1c0103af0 100644 --- a/drivers/core/device-remove.c +++ b/drivers/core/device-remove.c @@ -58,8 +58,14 @@ static int device_chld_remove(struct udevice *dev, uint flags)
list_for_each_entry_safe(pos, n, &dev->child_head, sibling_node) { ret = device_remove(pos, flags);
if (ret)return ret;
/** Don't stop on error here, the remaining child devices still* need to get removed.*/if (ret) {debug("%s: device_remove(%s) returned %d\n",__func__, pos->name, ret);} } return 0;-- 2.12.2
Regards, Simon
Hi Simon,
On 29.04.2017 02:26, Simon Glass wrote:
On 24 April 2017 at 01:48, Stefan Roese sr@denx.de wrote:
On my x86 platform I've noticed, that calling dm_uninit() or the new function dm_remove_devices_flags() does not remove the desired device at all. Debugging showed, that the serial uclass returns -EPERM in serial_pre_remove() and this leads to a complete stop of the device removal pretty early, as the serial device is one of the first ones in the DM. Here the dm tree output:
=> dm tree Class Probed Name
root [ + ] root_driver rsa_mod_exp [ ] |-- mod_exp_sw serial [ + ] |-- serial rtc [ ] |-- rtc timer [ + ] |-- tsc-timer syscon [ + ] |-- pch_pinctrl ...
In this example, device_remove(root) will stop directly after trying to remove the "serial" device.
To solve this problem, this patch removes the return upon error check in the device_remove() call in device_chld_remove(). This leads to device_chld_remove() continuing with the device_remove() call to the following child devices.
Signed-off-by: Stefan Roese sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com
v2:
- Add debug() output in error case
drivers/core/device-remove.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
I thought that your change to force removal of the stdio dev would make this change unnecessary?
Yes, the force removal made this change unnecessary in this specific case. But...
I really would rather fix the root cause if we can.
... the current implementation to exit the loop over all children upon error and not remove the remaining children is wrong IMO. All devices should at least be tried to get removed, even if one fails to get removed. This is what this patch makes sure of.
Thanks, Stefan
Hi Stefan,
On 1 May 2017 at 00:14, Stefan Roese sr@denx.de wrote:
Hi Simon,
On 29.04.2017 02:26, Simon Glass wrote:
On 24 April 2017 at 01:48, Stefan Roese sr@denx.de wrote:
On my x86 platform I've noticed, that calling dm_uninit() or the new function dm_remove_devices_flags() does not remove the desired device at all. Debugging showed, that the serial uclass returns -EPERM in serial_pre_remove() and this leads to a complete stop of the device removal pretty early, as the serial device is one of the first ones in the DM. Here the dm tree output:
=> dm tree Class Probed Name
root [ + ] root_driver rsa_mod_exp [ ] |-- mod_exp_sw serial [ + ] |-- serial rtc [ ] |-- rtc timer [ + ] |-- tsc-timer syscon [ + ] |-- pch_pinctrl ...
In this example, device_remove(root) will stop directly after trying to remove the "serial" device.
To solve this problem, this patch removes the return upon error check in the device_remove() call in device_chld_remove(). This leads to device_chld_remove() continuing with the device_remove() call to the following child devices.
Signed-off-by: Stefan Roese sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com
v2:
- Add debug() output in error case
drivers/core/device-remove.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
I thought that your change to force removal of the stdio dev would make this change unnecessary?
Yes, the force removal made this change unnecessary in this specific case. But...
I really would rather fix the root cause if we can.
... the current implementation to exit the loop over all children upon error and not remove the remaining children is wrong IMO. All devices should at least be tried to get removed, even if one fails to get removed. This is what this patch makes sure of.
Yes I see that, but not being able to remove is actually an error. In the normal course of events, a device that will not remove itself is likely buggy.
What do you think about adding a new remove flag to indicate that failures should be skipped?
Regards, Simon
Hi Simon,
On 02.05.2017 13:27, Simon Glass wrote:
On 1 May 2017 at 00:14, Stefan Roese sr@denx.de wrote:
Hi Simon,
On 29.04.2017 02:26, Simon Glass wrote:
On 24 April 2017 at 01:48, Stefan Roese sr@denx.de wrote:
On my x86 platform I've noticed, that calling dm_uninit() or the new function dm_remove_devices_flags() does not remove the desired device at all. Debugging showed, that the serial uclass returns -EPERM in serial_pre_remove() and this leads to a complete stop of the device removal pretty early, as the serial device is one of the first ones in the DM. Here the dm tree output:
=> dm tree Class Probed Name
root [ + ] root_driver rsa_mod_exp [ ] |-- mod_exp_sw serial [ + ] |-- serial rtc [ ] |-- rtc timer [ + ] |-- tsc-timer syscon [ + ] |-- pch_pinctrl ...
In this example, device_remove(root) will stop directly after trying to remove the "serial" device.
To solve this problem, this patch removes the return upon error check in the device_remove() call in device_chld_remove(). This leads to device_chld_remove() continuing with the device_remove() call to the following child devices.
Signed-off-by: Stefan Roese sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com
v2:
- Add debug() output in error case
drivers/core/device-remove.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
I thought that your change to force removal of the stdio dev would make this change unnecessary?
Yes, the force removal made this change unnecessary in this specific case. But...
I really would rather fix the root cause if we can.
... the current implementation to exit the loop over all children upon error and not remove the remaining children is wrong IMO. All devices should at least be tried to get removed, even if one fails to get removed. This is what this patch makes sure of.
Yes I see that, but not being able to remove is actually an error. In the normal course of events, a device that will not remove itself is likely buggy.
Isn't it enough then to just print an error message in this case in this loop - change debug() to printf() in this current patch version? Then "users" of this code will be aware of such remove failures and can take appropriate actions (fix bug etc in their setup).
What do you think about adding a new remove flag to indicate that failures should be skipped?
I'm a bit afraid that this makes the code overly complex. But if you prefer to have it this way, then I can come up with such a version as well. Just let me know.
Thanks, Stefan
Hi Stefan,
On 2 May 2017 at 05:45, Stefan Roese sr@denx.de wrote:
Hi Simon,
On 02.05.2017 13:27, Simon Glass wrote:
On 1 May 2017 at 00:14, Stefan Roese sr@denx.de wrote:
Hi Simon,
On 29.04.2017 02:26, Simon Glass wrote:
On 24 April 2017 at 01:48, Stefan Roese sr@denx.de wrote:
On my x86 platform I've noticed, that calling dm_uninit() or the new function dm_remove_devices_flags() does not remove the desired device at all. Debugging showed, that the serial uclass returns -EPERM in serial_pre_remove() and this leads to a complete stop of the device removal pretty early, as the serial device is one of the first ones in the DM. Here the dm tree output:
=> dm tree Class Probed Name
root [ + ] root_driver rsa_mod_exp [ ] |-- mod_exp_sw serial [ + ] |-- serial rtc [ ] |-- rtc timer [ + ] |-- tsc-timer syscon [ + ] |-- pch_pinctrl ...
In this example, device_remove(root) will stop directly after trying to remove the "serial" device.
To solve this problem, this patch removes the return upon error check in the device_remove() call in device_chld_remove(). This leads to device_chld_remove() continuing with the device_remove() call to the following child devices.
Signed-off-by: Stefan Roese sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com
v2:
- Add debug() output in error case
drivers/core/device-remove.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
I thought that your change to force removal of the stdio dev would make this change unnecessary?
Yes, the force removal made this change unnecessary in this specific case. But...
I really would rather fix the root cause if we can.
... the current implementation to exit the loop over all children upon error and not remove the remaining children is wrong IMO. All devices should at least be tried to get removed, even if one fails to get removed. This is what this patch makes sure of.
Yes I see that, but not being able to remove is actually an error. In the normal course of events, a device that will not remove itself is likely buggy.
Isn't it enough then to just print an error message in this case in this loop - change debug() to printf() in this current patch version? Then "users" of this code will be aware of such remove failures and can take appropriate actions (fix bug etc in their setup).
Possibly, but programmatically it becomes impossible to detect a failure. Say the USB fails to stop its DMA, we might want to reboot rather than continue to boot Linux and crash.
What do you think about adding a new remove flag to indicate that failures should be skipped?
I'm a bit afraid that this makes the code overly complex. But if you prefer to have it this way, then I can come up with such a version as well. Just let me know.
I don't think the complexity is too great. It does need a new test. But I think we should hold the line on error checking even with remove(), by default.
Thanks, Stefan
Regards, Simon
Hi Simon,
On 04.05.2017 18:50, Simon Glass wrote:
<snip>
... the current implementation to exit the loop over all children upon error and not remove the remaining children is wrong IMO. All devices should at least be tried to get removed, even if one fails to get removed. This is what this patch makes sure of.
Yes I see that, but not being able to remove is actually an error. In the normal course of events, a device that will not remove itself is likely buggy.
Isn't it enough then to just print an error message in this case in this loop - change debug() to printf() in this current patch version? Then "users" of this code will be aware of such remove failures and can take appropriate actions (fix bug etc in their setup).
Possibly, but programmatically it becomes impossible to detect a failure. Say the USB fails to stop its DMA, we might want to reboot rather than continue to boot Linux and crash.
Okay, I see your point.
What do you think about adding a new remove flag to indicate that failures should be skipped?
I'm a bit afraid that this makes the code overly complex. But if you prefer to have it this way, then I can come up with such a version as well. Just let me know.
I don't think the complexity is too great. It does need a new test. But I think we should hold the line on error checking even with remove(), by default.
Understood. How about doing it this way: You drop this patch from the series for now (it still works for us with the force remove of the serial driver) and apply the remaining patches. I'll try to get back to this skip-failures flag implementation in a few days / weeks.
Is this okay for you?
Thanks, Stefan
Hi Stefan,
On 8 May 2017 at 01:35, Stefan Roese sr@denx.de wrote:
Hi Simon,
On 04.05.2017 18:50, Simon Glass wrote:
<snip>
... the current implementation to exit the loop over all children upon error and not remove the remaining children is wrong IMO. All devices should at least be tried to get removed, even if one fails to get removed. This is what this patch makes sure of.
Yes I see that, but not being able to remove is actually an error. In the normal course of events, a device that will not remove itself is likely buggy.
Isn't it enough then to just print an error message in this case in this loop - change debug() to printf() in this current patch version? Then "users" of this code will be aware of such remove failures and can take appropriate actions (fix bug etc in their setup).
Possibly, but programmatically it becomes impossible to detect a failure. Say the USB fails to stop its DMA, we might want to reboot rather than continue to boot Linux and crash.
Okay, I see your point.
What do you think about adding a new remove flag to indicate that failures should be skipped?
I'm a bit afraid that this makes the code overly complex. But if you prefer to have it this way, then I can come up with such a version as well. Just let me know.
I don't think the complexity is too great. It does need a new test. But I think we should hold the line on error checking even with remove(), by default.
Understood. How about doing it this way: You drop this patch from the series for now (it still works for us with the force remove of the serial driver) and apply the remaining patches. I'll try to get back to this skip-failures flag implementation in a few days / weeks.
Is this okay for you?
Yes that's fine.
Thanks, Stefan
Regards, Simon
participants (4)
-
Bin Meng -
Jagan Teki -
Simon Glass -
Stefan Roese