* Re: Re: [PATCH v3] serial: mps2-uart: Check for error irq
@ 2021-12-23 13:27 Jiasheng Jiang
2021-12-23 14:26 ` Robin Murphy
0 siblings, 1 reply; 2+ messages in thread
From: Jiasheng Jiang @ 2021-12-23 13:27 UTC (permalink / raw)
To: robin.murphy, andy.shevchenko, gregkh, jirislaby, liviu.dudau,
sudeep.holla, lorenzo.pieralisi
Cc: linux-serial, linux-arm-kernel, linux-kernel, Jiasheng Jiang
On 2021-12-23 12:54, Robin Murphy wrote:
>> Because of the possible failure of the platform_get_irq(), it should be
>> better to check it to avoid the use of error irq.
>
> As far as I can see, the only "use" of error values is that they will be
> passed to request_irq(), which will then return -EINVAL because they are
> not valid IRQ numbers, and that error will be handled appropriately. I
> think that's a relatively common pattern, so your commit message should
> really describe why you think it's a problem and why this addition is a
> meaningful improvement.
Thanks for your reminder, and I correct my commit message as follow.
If that's ok, I will correct my other patches like this.
For the possible failure of the platform_get_irq(), the returned irq
could be error number and will finally cause the failure of the request_irq().
So it might be better to check just now in order to avoid the waste of
later processes.
Sincerely thanks,
Jiasheng
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH v3] serial: mps2-uart: Check for error irq
2021-12-23 13:27 Re: [PATCH v3] serial: mps2-uart: Check for error irq Jiasheng Jiang
@ 2021-12-23 14:26 ` Robin Murphy
0 siblings, 0 replies; 2+ messages in thread
From: Robin Murphy @ 2021-12-23 14:26 UTC (permalink / raw)
To: Jiasheng Jiang, andy.shevchenko, gregkh, jirislaby, liviu.dudau,
sudeep.holla, lorenzo.pieralisi
Cc: linux-serial, linux-arm-kernel, linux-kernel
On 2021-12-23 13:27, Jiasheng Jiang wrote:
> On 2021-12-23 12:54, Robin Murphy wrote:
>>> Because of the possible failure of the platform_get_irq(), it should be
>>> better to check it to avoid the use of error irq.
>>
>> As far as I can see, the only "use" of error values is that they will be
>> passed to request_irq(), which will then return -EINVAL because they are
>> not valid IRQ numbers, and that error will be handled appropriately. I
>> think that's a relatively common pattern, so your commit message should
>> really describe why you think it's a problem and why this addition is a
>> meaningful improvement.
>
> Thanks for your reminder, and I correct my commit message as follow.
> If that's ok, I will correct my other patches like this.
>
> For the possible failure of the platform_get_irq(), the returned irq
> could be error number and will finally cause the failure of the request_irq().
> So it might be better to check just now in order to avoid the waste of
> later processes.
Even better, consider that platform_get_irq() can now in certain cases
return -EPROBE_DEFER, and the consequences of letting request_irq()
effectively convert that into -EINVAL, even at probe time rather than
later on ;)
Cheers,
Robin.
>
> Sincerely thanks,
> Jiasheng
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2021-12-23 14:26 ` Robin Murphy
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