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Message-ID: <2ce27899-684f-4fe2-4401-a66649b35d60@leemhuis.info>
Date:   Fri, 22 Apr 2022 16:29:22 +0200
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Subject: Re: [REGRESSION] Missing IRQ via amd_gpio
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From:   Thorsten Leemhuis <regressions@leemhuis.info>
To:     Takashi Iwai <tiwai@suse.de>
Cc:     Shreeya Patel <shreeya.patel@collabora.com>,
        linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
        regressions@lists.linux.dev,
        Mario Limonciello <mario.limonciello@amd.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <brgl@bgdev.pl>
References: <s5ha6cdtglj.wl-tiwai@suse.de>
 <e4c9bb60-210d-243a-e225-6b3546c0b42b@leemhuis.info>
In-Reply-To: <e4c9bb60-210d-243a-e225-6b3546c0b42b@leemhuis.info>
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On 22.04.22 16:17, Thorsten Leemhuis wrote:
> Hi Takashi! Thx for CCing the regression list.
> 
> On 22.04.22 15:03, Takashi Iwai wrote:
>> Hi,
>>
>> we received a bug report for 5.17.3 kernel showing a new error:
>>
>>  amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x003D to IRQ, err -517
>>
>> Not only an error message but in practice this leads to a missing IRQ
>> assignment; the IRQ 27 is no longer assigned to amd_gpio driver.
>>
>> As the error number (EPROBE_DEFER) indicates, this seems to be the
>> side-effect of the recent fix, the upstream commit 5467801f1fcb
>> ("gpio: Restrict usage of GPIO chip irq members before
>> initialization").  As far as I understand, the problem is in
>> acpi_gpiochip_request_interrupts() call that is called from
>> gpiochip_add_irqchip() itself.  Since it's called before the
>> initialized flag set, it always fails now.
>>
>> Below is a temporary quick fix and it seems working.  But I'm not sure
>> whether I overlooked something obvious...
> 
> A patch that afaics will fix this hopefully should get merged really
> soon now:
> 
> https://lore.kernel.org/all/20220422131452.20757-1-mario.limonciello@amd.com/
> 
> See also v1:
> 
> https://lore.kernel.org/all/20220414025705.598-1-mario.limonciello@amd.com/

Sorry, I shouldn't have stripped the rest of the message, mario might be
interested in at least the link, so here it is:

>> -- 8< --
>> From: Takashi Iwai <tiwai@suse.de>
>> Subject: [PATCH] gpio: Fix missing IRQ assginment for ACPI gpiochip
>> 
>> The recent fix for gpiolib caused an error like:
>>   amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x003D to IRQ, err -517
>> It indicates -EPROBE_DEFER, and since the function
>> acpi_gpiochip_request_interrupts() doesn't handle the deferred probe,
>> this leads to the missing IRQs. 
>> 
>> The problem is that acpi_gpiochip_request_interrupts() itself is
>> called from gpiochip_add_irqchip() but before gc->irq.initialized flag
>> is set.  For fixing the regression, let's move the call of
>> acpi_gpiochip_request_interrupts() after the initialized flag setup.
>> 
>> Fixes: 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members before initialization")
>> BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1198697
>> Signed-off-by: Takashi Iwai <tiwai@suse.de>
>> ---
>>  drivers/gpio/gpiolib.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
>> index 085348e08986..b7694171655c 100644
>> --- a/drivers/gpio/gpiolib.c
>> +++ b/drivers/gpio/gpiolib.c
>> @@ -1601,8 +1601,6 @@ static int gpiochip_add_irqchip(struct gpio_chip *gc,
>>  
>>  	gpiochip_set_irq_hooks(gc);
>>  
>> -	acpi_gpiochip_request_interrupts(gc);
>> -
>>  	/*
>>  	 * Using barrier() here to prevent compiler from reordering
>>  	 * gc->irq.initialized before initialization of above
>> @@ -1612,6 +1610,8 @@ static int gpiochip_add_irqchip(struct gpio_chip *gc,
>>  
>>  	gc->irq.initialized = true;
>>  
>> +	acpi_gpiochip_request_interrupts(gc);
>> +
>>  	return 0;
>>  }