Re: [PATCH 01/10] spi: dw: Add support for polled operation via no IRQ specified in DT

From: Lars Povlsen
Date: Tue May 19 2020 - 06:26:04 EST



Andy Shevchenko writes:

> On Wed, May 13, 2020 at 5:03 PM Lars Povlsen <lars.povlsen@xxxxxxxxxxxxx> wrote:
>>
>> With this change a SPI controller can be added without having a IRQ
>> associated, and causing all transfers to be polled. For SPI controllers
>> without DMA, this can significantly improve performance by less
>> interrupt handling overhead.
>
> ...
>
>> +#define VALID_IRQ(i) (i >= 0)
>
> drivers/rtc/rtc-cmos.c:95:#define is_valid_irq(n) ((n) > 0)
>
> Candidate to be in include/linux/irq.h ?
>
> ...
>
>> + if (VALID_IRQ(dws->irq))
>> + free_irq(dws->irq, master);
>
> Isn't free_irq() aware of invalid ones (not found IRQ in the tree or
> any other backend container won't do anything)?
>
>
>> err_free_master:
>> spi_controller_put(master);
>> return ret;
>> --
>> 2.26.2

I'll rework this with Serge.

Thank you!

--
Lars Povlsen,
Microchip