Re: [PATCH v2 1/3] spi: spi-mem: add automatic poll status functions

[Patrice CHOTARD <patrice.chotard@xxxxxxxxxxx>]

Hi Boris

On 5/10/21 11:22 AM, Boris Brezillon wrote:
> On Mon, 10 May 2021 10:46:48 +0200
> Patrice CHOTARD <patrice.chotard@xxxxxxxxxxx> wrote:
> 
>>>   
>>>> +
>>>> +	if (ctlr->mem_ops && ctlr->mem_ops->poll_status) {
>>>> +		ret = spi_mem_access_start(mem);
>>>> +		if (ret)
>>>> +			return ret;
>>>> +
>>>> +		reinit_completion(&ctlr->xfer_completion);
>>>> +
>>>> +		ret = ctlr->mem_ops->poll_status(mem, op, mask, match,
>>>> +						 timeout_ms);
>>>> +
>>>> +		ms = wait_for_completion_timeout(&ctlr->xfer_completion,
>>>> +						 msecs_to_jiffies(timeout_ms));  
>>>
>>> Why do you need to wait here? I'd expect the poll_status to take care
>>> of this wait.  
>>
>> It was a request from Mark Brown [1]. The idea is to implement
>> similar mechanism already used in SPI framework.
> 
> Well, you have to choose, either you pass a timeout to ->poll_status()
> and let the driver wait for the status change (and return -ETIMEDOUT if
> it didn't happen in time), or you do it here and the driver only has to
> signal the core completion object. I think it's preferable to let the
> driver handle the timeout though, because you don't know how the
> status check will be implemented, and it's not like the
> reinit_completion()+wait_for_completion_timeout() done here would
> greatly simplify the drivers wait logic anyway.
> 

Ok i will remove the reinit/wait_completion() as you suggested.
Thanks
Patrice