Subject: Re: [PATCH v1 1/2] ata: libahci_platform: Get rid of dup message when
 IRQ can't be retrieved
To:     Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        <linux-ide@vger.kernel.org>, <linux-kernel@vger.kernel.org>
CC:     Hans de Goede <hdegoede@redhat.com>, Jens Axboe <axboe@kernel.dk>
References: <20211209145937.77719-1-andriy.shevchenko@linux.intel.com>
 <d91cf14d-c7d8-1c61-9071-102f38e8c924@opensource.wdc.com>
From:   Sergey Shtylyov <s.shtylyov@omp.ru>
Organization: Open Mobile Platform
Message-ID: <febc7f73-929f-d8a6-ea01-5056b9101b46@omp.ru>
Date:   Fri, 10 Dec 2021 11:59:00 +0300
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On 12/10/21 1:49 AM, Damien Le Moal wrote:

>> platform_get_irq() will print a message when it fails.
>> No need to repeat this.
>>
>> While at it, drop redundant check for 0 as platform_get_irq() spills
>> out a big WARN() in such case.
> 
> The reason you should be able to remove the "if (!irq)" test is that
> platform_get_irq() never returns 0. At least, that is what the function kdoc
> says. But looking at platform_get_irq_optional(), which is called by
> platform_get_irq(), the out label is:
> 
> 	WARN(ret == 0, "0 is an invalid IRQ number\n");
> 	return ret;
> 
> So 0 will be returned as-is. That is rather weird. That should be fixed to
> return -ENXIO:
> 
> 	if (WARN(ret == 0, "0 is an invalid IRQ number\n"))
> 		return -ENXIO;
> 	return ret;

   My unmerged patch (https://marc.info/?l=linux-kernel&m=163623041902285) does this
but returns -EINVAL instead.

> Otherwise, I do not think that removing the "if (!irq)" hunk is safe. no ?

   Of course it isn't...

>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[...]

MBR, Sergey