[U-Boot] [PATCH] usb: gadget: Fix data aborts during USB ethernet boot
As seen on GCC 4.6 Linaro compiler, control_req buffer is not aligned on 4 byte boundaray causing data aborts in eth_setup -> conf_buf during dhcp boot over usb_ether. Fix the issue my aligning control_req buffer to 4-byte boundary.
Tested on am335x_evm platform (beaglebone). Applies on 2013.10-rc1 branch.
Cc: Tom Rini trini@ti.com Signed-off-by: Joel Fernandes joelf@ti.com --- drivers/usb/gadget/ether.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c index 579893c..251d7b2 100644 --- a/drivers/usb/gadget/ether.c +++ b/drivers/usb/gadget/ether.c @@ -849,7 +849,7 @@ static struct usb_gadget_strings stringtab = { };
/*============================================================================*/ -static u8 control_req[USB_BUFSIZ]; +static u8 control_req[USB_BUFSIZ] __attribute__ ((aligned(4))); #if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4))); #endif
Dear Joel Fernandes,
As seen on GCC 4.6 Linaro compiler, control_req buffer is not aligned on 4 byte boundaray causing data aborts in eth_setup -> conf_buf during dhcp boot over usb_ether. Fix the issue my aligning control_req buffer to 4-byte boundary.
Tested on am335x_evm platform (beaglebone). Applies on 2013.10-rc1 branch.
Cc: Tom Rini trini@ti.com Signed-off-by: Joel Fernandes joelf@ti.com
Please keep me in the CC next time.
drivers/usb/gadget/ether.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c index 579893c..251d7b2 100644 --- a/drivers/usb/gadget/ether.c +++ b/drivers/usb/gadget/ether.c @@ -849,7 +849,7 @@ static struct usb_gadget_strings stringtab = { };
/*======================================================================== ====*/ -static u8 control_req[USB_BUFSIZ]; +static u8 control_req[USB_BUFSIZ] __attribute__ ((aligned(4)));
Please make this cacheline aligned, so we get rid of bounce buffering of the requests on stupid hardware.
#if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4)));
This could also use fixing, but the STATUS_BYTECOUNT would need to be up-aligned as well then. Some DEFINE_CACHE_ALIGN_BUFFER might help in both cases here.
#endif
Best regards, Marek Vasut
On 08/27/2013 08:52 AM, Marek Vasut wrote:
Dear Joel Fernandes,
As seen on GCC 4.6 Linaro compiler, control_req buffer is not aligned on 4 byte boundaray causing data aborts in eth_setup -> conf_buf during dhcp boot over usb_ether. Fix the issue my aligning control_req buffer to 4-byte boundary.
Tested on am335x_evm platform (beaglebone). Applies on 2013.10-rc1 branch.
Cc: Tom Rini trini@ti.com Signed-off-by: Joel Fernandes joelf@ti.com
Please keep me in the CC next time.
Ok.
drivers/usb/gadget/ether.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c index 579893c..251d7b2 100644 --- a/drivers/usb/gadget/ether.c +++ b/drivers/usb/gadget/ether.c @@ -849,7 +849,7 @@ static struct usb_gadget_strings stringtab = { };
/*======================================================================== ====*/ -static u8 control_req[USB_BUFSIZ]; +static u8 control_req[USB_BUFSIZ] __attribute__ ((aligned(4)));
Please make this cacheline aligned, so we get rid of bounce buffering of the requests on stupid hardware.
#if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4)));
This could also use fixing, but the STATUS_BYTECOUNT would need to be up-aligned as well then. Some DEFINE_CACHE_ALIGN_BUFFER might help in both cases here.
Ok, how about __aligned(CONFIG_SYS_CACHELINE_SIZE) instead of defining a new DEFINE_CACHE_ALIGN_BUFFER macro?
Can you explain what you meant by STATUS_BYTECOUNT up-aligned and why its needed to be up-aligned?
Regards,
-Joel
#endif
Best regards, Marek Vasut
Dear Joel Fernandes,
On 08/27/2013 08:52 AM, Marek Vasut wrote:
Dear Joel Fernandes,
As seen on GCC 4.6 Linaro compiler, control_req buffer is not aligned on 4 byte boundaray causing data aborts in eth_setup -> conf_buf during dhcp boot over usb_ether. Fix the issue my aligning control_req buffer to 4-byte boundary.
Tested on am335x_evm platform (beaglebone). Applies on 2013.10-rc1 branch.
Cc: Tom Rini trini@ti.com Signed-off-by: Joel Fernandes joelf@ti.com
Please keep me in the CC next time.
Ok.
drivers/usb/gadget/ether.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c index 579893c..251d7b2 100644 --- a/drivers/usb/gadget/ether.c +++ b/drivers/usb/gadget/ether.c @@ -849,7 +849,7 @@ static struct usb_gadget_strings stringtab = {
};
/*=====================================================================
====*/ -static u8 control_req[USB_BUFSIZ]; +static u8 control_req[USB_BUFSIZ] __attribute__ ((aligned(4)));
Please make this cacheline aligned, so we get rid of bounce buffering of the requests on stupid hardware.
#if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4)));
This could also use fixing, but the STATUS_BYTECOUNT would need to be up-aligned as well then. Some DEFINE_CACHE_ALIGN_BUFFER might help in both cases here.
Ok, how about __aligned(CONFIG_SYS_CACHELINE_SIZE) instead of defining a new DEFINE_CACHE_ALIGN_BUFFER macro?
THis is already defined and used throughout the USB code, check include/common.h IIRC.
Can you explain what you meant by STATUS_BYTECOUNT up-aligned and why its needed to be up-aligned?
it's 16 bytes now, no? Up-align it to cacheline size.
Best regards, Marek Vasut
On 09/04/2013 04:38 PM, Marek Vasut wrote:
Dear Joel Fernandes,
On 08/27/2013 08:52 AM, Marek Vasut wrote:
Dear Joel Fernandes,
As seen on GCC 4.6 Linaro compiler, control_req buffer is not aligned on 4 byte boundaray causing data aborts in eth_setup -> conf_buf during dhcp boot over usb_ether. Fix the issue my aligning control_req buffer to 4-byte boundary.
Tested on am335x_evm platform (beaglebone). Applies on 2013.10-rc1 branch.
Cc: Tom Rini trini@ti.com Signed-off-by: Joel Fernandes joelf@ti.com
Please keep me in the CC next time.
Ok.
drivers/usb/gadget/ether.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c index 579893c..251d7b2 100644 --- a/drivers/usb/gadget/ether.c +++ b/drivers/usb/gadget/ether.c @@ -849,7 +849,7 @@ static struct usb_gadget_strings stringtab = {
};
/*=====================================================================
====*/ -static u8 control_req[USB_BUFSIZ]; +static u8 control_req[USB_BUFSIZ] __attribute__ ((aligned(4)));
Please make this cacheline aligned, so we get rid of bounce buffering of the requests on stupid hardware.
#if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4)));
This could also use fixing, but the STATUS_BYTECOUNT would need to be up-aligned as well then. Some DEFINE_CACHE_ALIGN_BUFFER might help in both cases here.
Ok, how about __aligned(CONFIG_SYS_CACHELINE_SIZE) instead of defining a new DEFINE_CACHE_ALIGN_BUFFER macro?
THis is already defined and used throughout the USB code, check include/common.h IIRC.
Can you explain what you meant by STATUS_BYTECOUNT up-aligned and why its needed to be up-aligned?
it's 16 bytes now, no? Up-align it to cacheline size.
Ok, that makes sense. Thanks. Hope below patch is OK, but I have to test it more once I am near a setup and can send out a proper patch later today.
If its ok can you explain technical reason for need to up-align array size to cacheline size, and why aligning only buffer location is not enough?
Also I saw the following comment before the macro definition: * Usage of this macro shall be avoided or used with extreme care!
Regards,
-Joel
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c index 579893c..700d5fb 100644 --- a/drivers/usb/gadget/ether.c +++ b/drivers/usb/gadget/ether.c @@ -849,9 +849,10 @@ static struct usb_gadget_strings stringtab = { };
/*============================================================================*/ -static u8 control_req[USB_BUFSIZ]; +DEFINE_CACHE_ALIGN_BUFFER(u8, control_req, USB_BUFSIZ); + #if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) -static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4))); +DEFINE_CACHE_ALIGN_BUFFER(u8, status_req, STATUS_BYTECOUNT); #endif
Dear Joel Fernandes,
On 09/04/2013 04:38 PM, Marek Vasut wrote:
Dear Joel Fernandes,
On 08/27/2013 08:52 AM, Marek Vasut wrote:
Dear Joel Fernandes,
As seen on GCC 4.6 Linaro compiler, control_req buffer is not aligned on 4 byte boundaray causing data aborts in eth_setup -> conf_buf during dhcp boot over usb_ether. Fix the issue my aligning control_req buffer to 4-byte boundary.
Tested on am335x_evm platform (beaglebone). Applies on 2013.10-rc1 branch.
Cc: Tom Rini trini@ti.com Signed-off-by: Joel Fernandes joelf@ti.com
Please keep me in the CC next time.
Ok.
drivers/usb/gadget/ether.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c index 579893c..251d7b2 100644 --- a/drivers/usb/gadget/ether.c +++ b/drivers/usb/gadget/ether.c @@ -849,7 +849,7 @@ static struct usb_gadget_strings stringtab = {
};
/*=================================================================== == ===
====*/ -static u8 control_req[USB_BUFSIZ]; +static u8 control_req[USB_BUFSIZ] __attribute__ ((aligned(4)));
Please make this cacheline aligned, so we get rid of bounce buffering of the requests on stupid hardware.
#if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4)));
This could also use fixing, but the STATUS_BYTECOUNT would need to be up-aligned as well then. Some DEFINE_CACHE_ALIGN_BUFFER might help in both cases here.
Ok, how about __aligned(CONFIG_SYS_CACHELINE_SIZE) instead of defining a new DEFINE_CACHE_ALIGN_BUFFER macro?
THis is already defined and used throughout the USB code, check include/common.h IIRC.
Can you explain what you meant by STATUS_BYTECOUNT up-aligned and why its needed to be up-aligned?
it's 16 bytes now, no? Up-align it to cacheline size.
Ok, that makes sense. Thanks. Hope below patch is OK, but I have to test it more once I am near a setup and can send out a proper patch later today.
If its ok can you explain technical reason for need to up-align array size to cacheline size, and why aligning only buffer location is not enough?
Also I saw the following comment before the macro definition:
- Usage of this macro shall be avoided or used with extreme care!
Regards,
-Joel
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c index 579893c..700d5fb 100644 --- a/drivers/usb/gadget/ether.c +++ b/drivers/usb/gadget/ether.c @@ -849,9 +849,10 @@ static struct usb_gadget_strings stringtab = { };
/*======================================================================== ====*/ -static u8 control_req[USB_BUFSIZ]; +DEFINE_CACHE_ALIGN_BUFFER(u8, control_req, USB_BUFSIZ);
#if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) -static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4))); +DEFINE_CACHE_ALIGN_BUFFER(u8, status_req, STATUS_BYTECOUNT); #endif
Yeah, I think so. Repost V2 and we should be cool here.
Best regards, Marek Vasut
participants (2)
-
Joel Fernandes -
Marek Vasut