[U-Boot] [PATCH v2 1/3] board_r: move initr_watchdog to be called after initr_serial

[U-Boot] [PATCH v2 1/3] board_r: move initr_watchdog to be called after initr_serial

[Weijie Gao]

The initr_watchdog is currently placed before initr_serial. The
initr_watchdog calls printf and printf finally calls ops->putc of a serial
driver.

However, gd->cur_serial_dev points to a udevice allocated in board_f. The
gd->cur_serial_dev->driver->ops->putc points the the code region before
relocation.

Some serial drivers call WATCHDOG_RESET() in ops->putc. When DM is enabled
for watchdog, watchdog_reset() is called. watchdog_reset() calls get_timer
to get current timer.

On some platforms the timer driver is also a DM driver. initr_watchdog is
placed right after initr_dm, which means the timer driver hasn't been
initialized. So dm_timer_init() is called. To create a new udevice, calloc
is called.

However start from ops->putc, u-boot execution flow is redirected into the
memory region before relocation (board_f). In board_f, dlmalloc hasn't
been initialized. The call to calloc will fail, and this will cause DM to
print out an error message, and it will call printf again, causing
recursive error outputs.

This patch places initr_watchdog after initr_serial to solve this issue.

Cc: Stefan Roese <sr@denx.de>
Reviewed-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
---
Changes since v1: move initr_watchdog instead of initr_serial
---
 common/board_r.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/common/board_r.c b/common/board_r.c
index 150e8cd424..df24021f2c 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -678,9 +678,6 @@ static init_fnc_t init_sequence_r[] = {
 #ifdef CONFIG_DM
 	initr_dm,
 #endif
-#if defined(CONFIG_WDT)
-	initr_watchdog,
-#endif
 #if defined(CONFIG_ARM) || defined(CONFIG_NDS32) || defined(CONFIG_RISCV) || \
 	defined(CONFIG_SANDBOX)
 	board_init,	/* Setup chipselects */
@@ -700,6 +697,9 @@ static init_fnc_t init_sequence_r[] = {
 	stdio_init_tables,
 	initr_serial,
 	initr_announce,
+#if defined(CONFIG_WDT)
+	initr_watchdog,
+#endif
 	INIT_FUNC_WATCHDOG_RESET
 #ifdef CONFIG_NEEDS_MANUAL_RELOC
 	initr_manual_reloc_cmdtable,
-- 
2.18.0

[U-Boot] [PATCH v2 1/3] board_r: move initr_watchdog to be called, after initr_serial

[Suniel Mahesh]

Hi,

May I know if this patch is still under review ?

I have converted OMAP3 watchdog driver into driver model for TI AM33XX based SOC and tested corresponding
patches on BeagleBone Black board.

Build was successful but board goes into a loop when turned on/runtime, problem identified and is in sync
with Weijie Gao's explanation and his patch for such behaviour (please follow this thread for explanation).

When initr_watchdog is moved/placed just after initr_serial, board is behaving normal. Tested on BeagleBone Black.

Please suggest if there are any workarounds for this problem.

Regards
-- 
Suniel Mahesh
Embedded Linux, Kernel & U-Boot engineer
https://github.com/sunielmahesh
www.tuxtrons.com
https://github.com/techveda
Hyderabad, India

[U-Boot] [PATCH v2 1/3] board_r: move initr_watchdog to be called after initr_serial

[Stefan Roese]

Cc'ing a few people

On 16.05.19 11:19, Weijie Gao wrote:
> The initr_watchdog is currently placed before initr_serial. The
> initr_watchdog calls printf and printf finally calls ops->putc of a serial
> driver.
> 
> However, gd->cur_serial_dev points to a udevice allocated in board_f. The
> gd->cur_serial_dev->driver->ops->putc points the the code region before
> relocation.
> 
> Some serial drivers call WATCHDOG_RESET() in ops->putc. When DM is enabled
> for watchdog, watchdog_reset() is called. watchdog_reset() calls get_timer
> to get current timer.
> 
> On some platforms the timer driver is also a DM driver. initr_watchdog is
> placed right after initr_dm, which means the timer driver hasn't been
> initialized. So dm_timer_init() is called. To create a new udevice, calloc
> is called.
> 
> However start from ops->putc, u-boot execution flow is redirected into the
> memory region before relocation (board_f). In board_f, dlmalloc hasn't
> been initialized. The call to calloc will fail, and this will cause DM to
> print out an error message, and it will call printf again, causing
> recursive error outputs.
> 
> This patch places initr_watchdog after initr_serial to solve this issue.
> 
> Cc: Stefan Roese <sr@denx.de>
> Reviewed-by: Ryder Lee <ryder.lee@mediatek.com>
> Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
> ---
> Changes since v1: move initr_watchdog instead of initr_serial
> ---
>   common/board_r.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/common/board_r.c b/common/board_r.c
> index 150e8cd424..df24021f2c 100644
> --- a/common/board_r.c
> +++ b/common/board_r.c
> @@ -678,9 +678,6 @@ static init_fnc_t init_sequence_r[] = {
>   #ifdef CONFIG_DM
>   	initr_dm,
>   #endif
> -#if defined(CONFIG_WDT)
> -	initr_watchdog,
> -#endif
>   #if defined(CONFIG_ARM) || defined(CONFIG_NDS32) || defined(CONFIG_RISCV) || \
>   	defined(CONFIG_SANDBOX)
>   	board_init,	/* Setup chipselects */
> @@ -700,6 +697,9 @@ static init_fnc_t init_sequence_r[] = {
>   	stdio_init_tables,
>   	initr_serial,
>   	initr_announce,
> +#if defined(CONFIG_WDT)
> +	initr_watchdog,
> +#endif
>   	INIT_FUNC_WATCHDOG_RESET
>   #ifdef CONFIG_NEEDS_MANUAL_RELOC
>   	initr_manual_reloc_cmdtable,

Reviewed-by: Stefan Roese <sr@denx.de>

Frank, does this patch fix the watchdog issue on your board as well?

Tom, could you please apply this patch to the upcoming release?

Thanks,
Stefan

[U-Boot] [PATCH v2 1/3] board_r: move initr_watchdog to be called after initr_serial

[Frank Wunderlich]

Hi Stefan/Tom

this Patch in combination with https://patchwork.ozlabs.org/patch/1113120/ seem to fix issues on bananapi-r2 /mt7623 (bootloop/hang on WDT servicing) if CONFIG_WATCHDOG is not set to "n" (else it will be set to y because of new "imply WATCHDOG" inside of "config WDT").

@tom can you please include this 2 Patches in master?

regards Frank

[U-Boot] [PATCH v2 1/3] board_r: move initr_watchdog to be called after initr_serial

[Stefan Roese]

Hi Frank,

On 29.06.19 10:44, Frank Wunderlich wrote:
> Hi Stefan/Tom
> 
> this Patch in combination with https://patchwork.ozlabs.org/patch/1113120/

This one already is applied in mainline:

https://gitlab.denx.de/u-boot/u-boot/commit/2bc1821e8662f9ed67cc6eeb680148bb5c148379

Even though the coding style is pretty messed up. We should clean this
file up a bit.

Thanks,
Stefan

[U-Boot] [PATCH v2 1/3] board_r: move initr_watchdog to be called after initr_serial

[Frank Wunderlich]

Hi

It looks this fix is not yet merged. Tom can you add it before release? Without it bpi-r2 and maybe other boards are broken.

Regards Frank

[U-Boot] [PATCH v2 1/3] board_r: move initr_watchdog to be called after initr_serial

[Frank Wunderlich]

Tested-by: Frank Wunderlich <frank-w@public-files.de>

[U-Boot] [PATCH v2 1/3] board_r: move initr_watchdog to be called after initr_serial

[Suniel Mahesh]

Agreed with frank. My patches for watchdog DM conversion depends on this change set.

tested on AM335x based Beaglebone Black

Tested-by: Suniel Mahesh <sunil.m@techveda.org>

Regards
-- 
Suniel Mahesh
Embedded Linux, Kernel & U-Boot engineer
https://github.com/sunielmahesh
www.tuxtrons.com
https://github.com/techveda
Hyderabad, India

[U-Boot] [PATCH v2 1/3] board_r: move initr_watchdog to be called after initr_serial

[Tom Rini]

On Thu, May 16, 2019 at 05:19:13PM +0800, Weijie Gao wrote:

> The initr_watchdog is currently placed before initr_serial. The
> initr_watchdog calls printf and printf finally calls ops->putc of a serial
> driver.
> 
> However, gd->cur_serial_dev points to a udevice allocated in board_f. The
> gd->cur_serial_dev->driver->ops->putc points the the code region before
> relocation.
> 
> Some serial drivers call WATCHDOG_RESET() in ops->putc. When DM is enabled
> for watchdog, watchdog_reset() is called. watchdog_reset() calls get_timer
> to get current timer.
> 
> On some platforms the timer driver is also a DM driver. initr_watchdog is
> placed right after initr_dm, which means the timer driver hasn't been
> initialized. So dm_timer_init() is called. To create a new udevice, calloc
> is called.
> 
> However start from ops->putc, u-boot execution flow is redirected into the
> memory region before relocation (board_f). In board_f, dlmalloc hasn't
> been initialized. The call to calloc will fail, and this will cause DM to
> print out an error message, and it will call printf again, causing
> recursive error outputs.
> 
> This patch places initr_watchdog after initr_serial to solve this issue.
> 
> Cc: Stefan Roese <sr@denx.de>
> Reviewed-by: Ryder Lee <ryder.lee@mediatek.com>
> Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
> Reviewed-by: Stefan Roese <sr@denx.de>
> Tested-by: Frank Wunderlich <frank-w@public-files.de>
> Tested-by: Suniel Mahesh <sunil.m@techveda.org>

Applied to u-boot/master, thanks!

-- 
Tom
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