Re: [PATCH v2] platform: finally disallow IRQ0 in platform_get_irq() and its ilk

From: Sergey Shtylyov
Date: Wed Apr 27 2022 - 15:08:03 EST


On 4/26/22 1:46 PM, Greg Kroah-Hartman wrote:

>> The commit a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is
>> invalid") only calls WARN() when IRQ0 is about to be returned, however
>> using IRQ0 is considered invalid (according to Linus) outside the arch/
>> code where it's used by the i8253 drivers. Many driver subsystems treat
>> 0 specially (e.g. as an indication of the polling mode by libata), so
>> the users of platform_get_irq[_byname]() in them would have to filter
>> out IRQ0 explicitly and this (quite obviously) doesn't scale...
>> Let's finally get this straight and return -EINVAL instead of IRQ0!
>> Fixes: a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid")
>> Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
>> Acked-by: Marc Zyngier <maz@xxxxxxxxxx>


> Ok, let's try this now.

Well, better late than never! :-)

> Worst case, we revert it later :)

Please just don't revert it outright on the 1st issue report -- give me time
to look at the issue(s) reported...
BTW, I've CC'ed you on the SH patch that avoids using IRQ0. Please help to
merge it (v1/v2 were posted on February 11th and there was no motion since then)!

> thanks,
> greg k-h

MBR, Sergey