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

[Marek Vasut]

On 6/14/24 4:02 PM, Patrice CHOTARD wrote:
> 
> 
> 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

Thank you !