2021-12-21 07:30:28

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH 1/3] tty: serial: meson: modify request_irq and free_irq

On Tue, Dec 21, 2021 at 03:16:32PM +0800, Yu Tu wrote:
> Change request_irq to devm_request_irq and free_irq to devm_free_irq.
> It's better to change the code this way.

Why? What did this fix up? You still are manually requesting and
freeing the irq. What bug did you fix?

>
> The IRQF_SHARED interrupt flag was added because an interrupt error was
> detected when the serial port was opened twice in a row on the project.

That is a different change. Make that a different patch.

thanks,

greg k-h


2021-12-22 08:44:28

by Yu Tu

[permalink] [raw]
Subject: Re: [PATCH 1/3] tty: serial: meson: modify request_irq and free_irq



On 2021/12/21 15:30, Greg Kroah-Hartman wrote:
> [ EXTERNAL EMAIL ]
>
> On Tue, Dec 21, 2021 at 03:16:32PM +0800, Yu Tu wrote:
>> Change request_irq to devm_request_irq and free_irq to devm_free_irq.
>> It's better to change the code this way.
>
> Why? What did this fix up? You still are manually requesting and
> freeing the irq. What bug did you fix?
>
I think this is exactly what you said. It's not necessary.
>>
>> The IRQF_SHARED interrupt flag was added because an interrupt error was
>> detected when the serial port was opened twice in a row on the project.
>
> That is a different change. Make that a different patch.
>
The main purpose of this change is that I found some users in the actual
project with the following usages:
(1)open(/dev/ttyAML0);
(2)open(/dev/ttyAML0);
The open function calls the meson_uart_startup function. If this is the
case, an interrupt error is reported.So So the IRQF_SHARED flag was added.

I'm going to do this for now, remove free_irq and request_irq
function,then add devm_request_irq in meson_uart_probe function.
This solves the above problem without adding IRQF_SHARED.
> thanks,
>
> greg k-h
>