[PATCH] ARM: stm32: Ping IWDG on exit from PSCI suspend code

[Patrice CHOTARD]

On 6/14/24 15:06, Marek Vasut wrote:
> On 6/14/24 2:00 PM, Patrice CHOTARD wrote:
>>
>>
>> On 4/20/24 00:03, Marek Vasut wrote:
>>> Make sure the OS would not get any spurious IWDG pretimeout IRQ
>>> right after the system wakes up. This may happen in case the SoC
>>> got woken up by another source than the IWDG pretimeout and the
>>> pretimeout IRQ arrived immediately afterward, but too late to be
>>> handled by the suspend main loop. In case either of the IWDG is
>>> enabled, ping it first and then return to the OS.
>>>
>>> Signed-off-by: Marek Vasut <marex at denx.de>
>>> ---
>>> Cc: Igor Opaniuk <igor.opaniuk at foundries.io>
>>> Cc: Patrice Chotard <patrice.chotard at foss.st.com>
>>> Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
>>> Cc: Simon Glass <sjg at chromium.org>
>>> Cc: Tom Rini <trini at konsulko.com>
>>> Cc: u-boot at dh-electronics.com
>>> Cc: uboot-stm32 at st-md-mailman.stormreply.com
>>> ---
>>>   arch/arm/mach-stm32mp/stm32mp1/psci.c | 21 +++++++++++++++++++++
>>>   1 file changed, 21 insertions(+)
>>>
>>> diff --git a/arch/arm/mach-stm32mp/stm32mp1/psci.c b/arch/arm/mach-stm32mp/stm32mp1/psci.c
>>> index 4f2379df45f..e99103910d9 100644
>>> --- a/arch/arm/mach-stm32mp/stm32mp1/psci.c
>>> +++ b/arch/arm/mach-stm32mp/stm32mp1/psci.c
>>> @@ -808,6 +808,27 @@ void __secure psci_system_suspend(u32 __always_unused function_id,
>>>       writel(SYSCFG_CMPENR_MPUEN, STM32_SYSCFG_BASE + SYSCFG_CMPENSETR);
>>>       clrbits_le32(STM32_SYSCFG_BASE + SYSCFG_CMPCR, SYSCFG_CMPCR_SW_CTRL);
>>>   +    /*
>>> +     * Make sure the OS would not get any spurious IWDG pretimeout IRQ
>>> +     * right after the system wakes up. This may happen in case the SoC
>>> +     * got woken up by another source than the IWDG pretimeout and the
>>> +     * pretimeout IRQ arrived immediately afterward, but too late to be
>>> +     * handled by the main loop above. In case either of the IWDG is
>>> +     * enabled, ping it first and then return to the OS.
>>> +     */
>>> +
>>> +    /* Ping IWDG1 and ACK pretimer IRQ */
>>> +    if (gic_enabled[4] & BIT(22)) {
>>> +        writel(IWDG_KR_RELOAD_KEY, STM32_IWDG1_BASE + IWDG_KR);
>>> +        writel(IWDG_EWCR_EWIC, STM32_IWDG1_BASE + IWDG_EWCR);
>>> +    }
>>> +
>>> +    /* Ping IWDG2 and ACK pretimer IRQ */
>>> +    if (gic_enabled[4] & BIT(23)) {
>>> +        writel(IWDG_KR_RELOAD_KEY, STM32_IWDG2_BASE + IWDG_KR);
>>> +        writel(IWDG_EWCR_EWIC, STM32_IWDG2_BASE + IWDG_EWCR);
>>> +    }
>>> +
>>>       /*
>>>        * The system has resumed successfully. Rewrite LR register stored
>>>        * on stack with 'ep' value, so that on return from this PSCI call,
>> Applied to u-boot-stm32/next
> 
> This is a fix, should go into /master .

Ah yes :-( , i will send another PR for fixes on monday

Thanks for pointing this

PAtrice