[PATCH] board: mediatek: disable watchdog on BananaPi R2

[Heinrich Schuchardt]

Am 11. Januar 2021 08:02:12 MEZ schrieb Stefan Roese <sr at denx.de>:
>Added Heinrich to Cc.
>
>On 10.01.21 19:44, Matthias Brugger wrote:
>> On 09/01/2021 15:57, Stefan Roese wrote:
>>> On 09.01.21 03:32, Matthias Brugger wrote:
>>>> On 08/01/2021 08:39, Stefan Roese wrote:
>>>>> On 07.01.21 16:36, matthias.bgg at kernel.org wrote:
>>>>>> From: Matthias Brugger <mbrugger at suse.com>
>>>>>>
>>>>>> Watchdog timeout comes in before we are able to load the
>>>>>> kernel and reset the watchdog. Disable the watchdog late in the
>boot
>>>>>> process to be able to boot the board.
>>>>>
>>>>> Can't you change the WDT reset timeout instead to a higher value?
>>>>>
>>>>
>>>> I tried that, but the HW has a max timeout of 15984 ms.
>Unfortunately that's not
>>>> enough.
>>>
>>> Nearly 16 seconds is not enough to boot into Linux so that the Linux
>>> watchdog daemon can take control?
>>>
>> 
>> Exactly. I'm using a standard distro image. I think the main problem
>is, that it
>> needs 14 seconds for the EFI stub to actually boot the kernel.
>
>I've not much experience (yet) with the "EFI stub". But if it takes
>this
>long, wouldn't it make sense that this stub also supports the WDT?

efi_timer_check() calls WATCHDOG_RESET() trying to avoid that the hardware watchdog is triggered. There is a software watchdog defaulting to 5 minutes in efi_watchdog.c which can be modified via the EFI API.

Is there a U-Boot API to disable the hardware watchdog?

Best regards

Heinrich


>
>Thanks,
>Stefan
>
>> I've already the
>> watchdog timer as build-in (which is not the best to do, taking into
>account
>> that we don't want to bloat our distro kernel with random board
>specific drivers
>> build-in. If we I had the watchdog driver as kernel module it would
>take forever
>> to get that loaded.
>> 
>> You can find a serial log with timestamp from the moment U-Boot got
>loaded until
>> the kernel actually boots here:
>> https://paste.opensuse.org/98390849
>> 
>> Regards,
>> Matthias
>> 
>>> Thanks,
>>> Stefan
>>>
>>>> Regards,
>>>> Matthias
>>>>
>>>>> Thanks,
>>>>> Stefan
>>>>>
>>>>>> Signed-off-by: Matthias Brugger <mbrugger at suse.com>
>>>>>>
>>>>>> ---
>>>>>>
>>>>>>     board/mediatek/mt7623/mt7623_rfb.c | 8 ++++++++
>>>>>>     configs/mt7623n_bpir2_defconfig    | 1 +
>>>>>>     2 files changed, 9 insertions(+)
>>>>>>
>>>>>> diff --git a/board/mediatek/mt7623/mt7623_rfb.c
>>>>>> b/board/mediatek/mt7623/mt7623_rfb.c
>>>>>> index 984e75ccaf..22120be412 100644
>>>>>> --- a/board/mediatek/mt7623/mt7623_rfb.c
>>>>>> +++ b/board/mediatek/mt7623/mt7623_rfb.c
>>>>>> @@ -5,6 +5,7 @@
>>>>>>       #include <common.h>
>>>>>>     #include <mmc.h>
>>>>>> +#include <watchdog.h>
>>>>>>       DECLARE_GLOBAL_DATA_PTR;
>>>>>>     @@ -40,3 +41,10 @@ int mmc_get_env_dev(void)
>>>>>>         return mmc_get_boot_dev();
>>>>>>     }
>>>>>>     #endif
>>>>>> +
>>>>>> +#ifdef CONFIG_BOARD_LATE_INIT
>>>>>> +int board_late_init(void)
>>>>>> +{
>>>>>> +    wdt_stop(gd->watchdog_dev);
>>>>>> +}
>>>>>> +#endif
>>>>>> diff --git a/configs/mt7623n_bpir2_defconfig
>b/configs/mt7623n_bpir2_defconfig
>>>>>> index 9177c17dff..fe0b6259dd 100644
>>>>>> --- a/configs/mt7623n_bpir2_defconfig
>>>>>> +++ b/configs/mt7623n_bpir2_defconfig
>>>>>> @@ -14,6 +14,7 @@ CONFIG_FIT_VERBOSE=y
>>>>>>     CONFIG_BOOTDELAY=3
>>>>>>     CONFIG_SYS_CONSOLE_IS_IN_ENV=y
>>>>>>     CONFIG_DEFAULT_FDT_FILE="mt7623n-bananapi-bpi-r2.dtb"
>>>>>> +CONFIG_BOARD_LATE_INIT=y
>>>>>>     # CONFIG_DISPLAY_BOARDINFO is not set
>>>>>>     CONFIG_SYS_PROMPT="U-Boot> "
>>>>>>     CONFIG_CMD_BOOTMENU=y
>>>>>>
>>>>>
>>>>>
>>>>> Viele Grüße,
>>>>> Stefan
>>>>>
>>>>
>>>
>>>
>>> Viele Grüße,
>>> Stefan
>>>
>> 
>
>
>Viele Grüße,
>Stefan