[U-Boot] [PATCH] syscon: reset node list syscon_list after relocation
Reset the list head after the reallocation because the list syscon_list use allocated pointer and they are no more valid. This patch avoid issue (crash) when syscon_node_to_regmap() is called before and after reallocation.
Signed-off-by: Patrick Delaunay patrick.delaunay@st.com --- Hi
This patch correct a crash see on v2018.11-rc1 with my board stm32mp1 for the command "reset".
The crash is a side effect of 2 patches 1f6ca3f42f6edf143473159297f4c515b1cf36f6 sysreset: syscon: update regmap access to syscon
23471aed5c33e104d6fa64575932577618543bec board_f: Add reset status printing
With the first patch the syscon_node_to_regmap() is called each time that the class sysreset_syscon is probed.
=> in v2018.09 probe is done only when reset is requested
NB: for stm32mp1, the node rcc_reboot in tagged pre-relocated to support reset in pre-reloc phases (allow panic).
With the second patch, U-Boot probes all the sysreset uclass in preloc phase to allow to print the reset status, and the list is initialized in board_f / pre-reloc:
-> print_resetinfo --> uclass_first_device_err(UCLASS_SYSRESET, &dev); ---> syscon_reboot_probe() ----> syscon_node_to_regmap(node) -----> of_syscon_register() -------> list_add_tail(&syscon->list, &syscon_list);
During relocation, the content of syscon_list (static) is updated but the list use pointers allocated by malloc in pre-reloc phasis
And when I execute the reset command -> do_reset() --> reset_cpu() ---> sysreset_walk_halt(SYSRESET_COLD); ----> loop on device UCLASS_SYSRESET -----> syscon_reboot_probe() ------> syscon_node_to_regmap(node) -------> list_for_each_entry(entry, &syscon_list, list)
I have a crash here because the pointer syscon_list.next is invalid.
I solve the issue by resetting the list after reloc and it is working but I don't know if a more elegant solution exist (keep the list in .bss section to be set to 0).
Regards
Patrick
drivers/core/syscon-uclass.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/core/syscon-uclass.c b/drivers/core/syscon-uclass.c index 303e166..aacb43a 100644 --- a/drivers/core/syscon-uclass.c +++ b/drivers/core/syscon-uclass.c @@ -156,8 +156,15 @@ static struct syscon *of_syscon_register(ofnode node)
struct regmap *syscon_node_to_regmap(ofnode node) { + static int reloc_done; struct syscon *entry, *syscon = NULL;
+ /* content of list is not relocated (malloc): reinit when needed */ + if (!reloc_done && (gd->flags & GD_FLG_RELOC)) { + INIT_LIST_HEAD(&syscon_list); + reloc_done++; + } + list_for_each_entry(entry, &syscon_list, list) if (ofnode_equal(entry->node, node)) { syscon = entry;
Hi Patrick,
On 12 October 2018 at 09:26, Patrick Delaunay patrick.delaunay@st.com wrote:
Reset the list head after the reallocation because the list syscon_list use allocated pointer and they are no more valid. This patch avoid issue (crash) when syscon_node_to_regmap() is called before and after reallocation.
Signed-off-by: Patrick Delaunay patrick.delaunay@st.com
Hi
This patch correct a crash see on v2018.11-rc1 with my board stm32mp1 for the command "reset".
The crash is a side effect of 2 patches 1f6ca3f42f6edf143473159297f4c515b1cf36f6 sysreset: syscon: update regmap access to syscon
23471aed5c33e104d6fa64575932577618543bec board_f: Add reset status printing
With the first patch the syscon_node_to_regmap() is called each time that the class sysreset_syscon is probed.
=> in v2018.09 probe is done only when reset is requested
NB: for stm32mp1, the node rcc_reboot in tagged pre-relocated to support reset in pre-reloc phases (allow panic).
With the second patch, U-Boot probes all the sysreset uclass in preloc phase to allow to print the reset status, and the list is initialized in board_f / pre-reloc:
-> print_resetinfo --> uclass_first_device_err(UCLASS_SYSRESET, &dev); ---> syscon_reboot_probe() ----> syscon_node_to_regmap(node) -----> of_syscon_register() -------> list_add_tail(&syscon->list, &syscon_list);
During relocation, the content of syscon_list (static) is updated but the list use pointers allocated by malloc in pre-reloc phasis
And when I execute the reset command -> do_reset() --> reset_cpu() ---> sysreset_walk_halt(SYSRESET_COLD); ----> loop on device UCLASS_SYSRESET -----> syscon_reboot_probe() ------> syscon_node_to_regmap(node) -------> list_for_each_entry(entry, &syscon_list, list)
We have a similar issue with the timer - we set gd->timer to NULL in initr_dm().
I am not 100% what is going on here, but using pre-reloc devices (i.e. which were set up before relocation) after relocation is bad. We need to avoid that.
The syscon_list struct should be in the syscon uclass, i.e. declared as uclass priv data in UCLASS_DRIVER(syscon). We should not have this as free-standard static data. That's not how DM works...
So I guess Masahiro's patch needs to be adjusted.
Regards, Simon
Hi Simon,
From: sjg@google.com sjg@google.com On Behalf Of Simon Glass Sent: vendredi 19 octobre 2018 05:25
Hi Patrick,
On 12 October 2018 at 09:26, Patrick Delaunay patrick.delaunay@st.com wrote:
Reset the list head after the reallocation because the list syscon_list use allocated pointer and they are no more valid. This patch avoid issue (crash) when syscon_node_to_regmap() is called before and after reallocation.
Signed-off-by: Patrick Delaunay patrick.delaunay@st.com
Hi
This patch correct a crash see on v2018.11-rc1 with my board stm32mp1 for the command "reset".
The crash is a side effect of 2 patches 1f6ca3f42f6edf143473159297f4c515b1cf36f6 sysreset: syscon: update regmap access to syscon
23471aed5c33e104d6fa64575932577618543bec board_f: Add reset status printing
With the first patch the syscon_node_to_regmap() is called each time that the class sysreset_syscon is probed.
=> in v2018.09 probe is done only when reset is requested
NB: for stm32mp1, the node rcc_reboot in tagged pre-relocated to support reset in pre-reloc phases (allow panic).
With the second patch, U-Boot probes all the sysreset uclass in preloc phase to allow to print the reset status, and the list is initialized in board_f / pre-reloc:
-> print_resetinfo --> uclass_first_device_err(UCLASS_SYSRESET, &dev); ---> syscon_reboot_probe() ----> syscon_node_to_regmap(node) -----> of_syscon_register() -------> list_add_tail(&syscon->list, &syscon_list);
During relocation, the content of syscon_list (static) is updated but the list use pointers allocated by malloc in pre-reloc phasis
And when I execute the reset command -> do_reset() --> reset_cpu() ---> sysreset_walk_halt(SYSRESET_COLD); ----> loop on device UCLASS_SYSRESET -----> syscon_reboot_probe() ------> syscon_node_to_regmap(node) -------> list_for_each_entry(entry, &syscon_list, list)
We have a similar issue with the timer - we set gd->timer to NULL in initr_dm().
I am not 100% what is going on here, but using pre-reloc devices (i.e. which were set up before relocation) after relocation is bad. We need to avoid that.
Ok, I agree with you.
The syscon_list struct should be in the syscon uclass, i.e. declared as uclass priv data in UCLASS_DRIVER(syscon). We should not have this as free-standard static data. That's not how DM works...
So I guess Masahiro's patch needs to be adjusted.
Today, I read your comment and I start to move the list in syscon uclass priv data (I just discovered the uclass priv data).
But after some time spent with this list, I prefer completely remove it and have the same behavior with DM functions (as a list is already managed for the drivers).
It is more that only a adjustment, I completely update the function syscon_node_to_regmap(): force bound to syscon driver and probe it when the syscon driver don't yet exist.....
=> Do you think that is a good solution ?
The function change to:
struct regmap *syscon_node_to_regmap(ofnode node) { struct udevice *dev; struct udevice *parent; ofnode ofnode = node; int ret;
if (!uclass_get_device_by_ofnode(UCLASS_SYSCON, node, &dev)) return syscon_get_regmap(dev);
if (!ofnode_device_is_compatible(node, "syscon")) return ERR_PTR(-EINVAL);
if (device_find_global_by_ofnode(ofnode, &parent)) parent = dm_root();
/* force bound to syscon class */ ret = device_bind_driver_to_node(parent, "syscon", ofnode_get_name(node), node, &dev); if (ret) return ERR_PTR(ret);
ret = device_probe(dev); if (ret) return ERR_PTR(ret);
return syscon_get_regmap(dev); }
Tested on my board, the initial issue is sole and I check the behavior with dm_dump_all(); It seems OK for my case (RCC driver) .
before relocation => syscon is correctly probed
Class index Probed Driver Name ----------------------------------------- root 0 [ + ] root_drive root_driver misc 0 [ ] stm32mp_bs |-- stm32mp_bsec simple_bus 0 [ + ] generic_si |-- soc serial 0 [ + ] serial_stm | |-- serial@40010000 misc 1 [ + ] stm32-rcc | |-- rcc@50000000 clk 0 [ + ] stm32mp1_c | | |-- stm32mp1_clk reset 0 [ ] stm32_rcc_ | | |-- stm32_rcc_reset syscon 1 [ + ] syscon | | `-- rcc@50000000 <<<< SYSCON PROBED sysreset 0 [ + ] syscon_reb | |-- rcc-reboot@50000000 mmc 0 [ ] stm32_sdmm | |-- sdmmc@58005000 blk 0 [ ] mmc_blk | | `-- sdmmc@58005000.blk
And it is also the case for syscon reset (when I execute the command reset)
STM32MP> reset resetting ... STM32MP> reset resetting ... Class index Probed Driver Name ----------------------------------------- root 0 [ + ] root_drive root_driver misc 0 [ + ] stm32mp_bs |-- stm32mp_bsec simple_bus 0 [ + ] generic_si |-- soc serial 0 [ + ] serial_stm | |-- serial@40010000 i2c 0 [ ] stm32f7-i2 | |-- i2c@40013000 i2c 1 [ ] stm32f7-i2 | |-- i2c@40015000 usb 0 [ ] dwc2_usb | |-- usb-otg@49000000 misc 1 [ + ] stm32-rcc | |-- rcc@50000000 clk 0 [ + ] stm32mp1_c | | |-- stm32mp1_clk reset 0 [ + ] stm32_rcc_ | | |-- stm32_rcc_reset syscon 4 [ + ] syscon | | `-- rcc@50000000 <<<<< SYSCON sysreset 0 [ + ] syscon_reb | |-- rcc-reboot@50000000
And the driver is not binded/probed by default (checked with dm tree)
STM32MP> dm tree Class index Probed Driver Name ----------------------------------------- root 0 [ + ] root_drive root_driver misc 0 [ + ] stm32mp_bs |-- stm32mp_bsec simple_bus 0 [ + ] generic_si |-- soc serial 0 [ + ] serial_stm | |-- serial@40010000 i2c 0 [ ] stm32f7-i2 | |-- i2c@40013000 i2c 1 [ ] stm32f7-i2 | |-- i2c@40015000 usb 0 [ ] dwc2_usb | |-- usb-otg@49000000 misc 1 [ + ] stm32-rcc | |-- rcc@50000000 <<<<< NO SYSCON child clk 0 [ + ] stm32mp1_c | | |-- stm32mp1_clk reset 0 [ + ] stm32_rcc_ | | `-- stm32_rcc_reset sysreset 0 [ ] syscon_reb | |-- rcc-reboot@50000000 syscon 0 [ ] stmp32mp_s | |-- pwr@50001000
Regards, Simon
Regards Patrick
participants (3)
-
Patrick DELAUNAY -
Patrick Delaunay
-
Simon Glass