lkml.org 
[lkml]   [2021]   [Apr]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] spi: spi-zynqmp-gqspi: Fix runtime PM imbalance in zynqmp_qspi_probe
From
Date
Hi Dinghao,

On 4/8/21 6:33 PM, Michal Simek wrote:
> ++
>
> On 4/8/21 11:25 AM, Dinghao Liu wrote:
>> When platform_get_irq() fails, a pairing PM usage counter
>> increment is needed to keep the counter balanced. It's the
>> same for the following error paths.
>>
>> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
>> ---
>> drivers/spi/spi-zynqmp-gqspi.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
>> index c8fa6ee18ae7..95963a2de64a 100644
>> --- a/drivers/spi/spi-zynqmp-gqspi.c
>> +++ b/drivers/spi/spi-zynqmp-gqspi.c
>> @@ -1197,6 +1197,7 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
>> return 0;
>>
>> clk_dis_all:
>> + pm_runtime_get_noresume(&pdev->dev);
>> pm_runtime_set_suspended(&pdev->dev);
>> pm_runtime_disable(&pdev->dev);
>> clk_disable_unprepare(xqspi->refclk);
>>
The imbalance is because pm_runtime_put_autosuspend is called to make
counter to be -1.

It looks strange that there is no counter increament op before
pm_runtime_put_autosuspend.

In my limited understanding, it should look like:

......

pm_runtime_enable

pm_runtime_get_sync   //increase counter to one to resume device

DO OPERATIONS HERE

pm_runtime_mark_last_busy
pm_runtime_put_autosuspend   //decrease counter to zero and trigger suspend

return 0;

error_path:

pm_runtime_put_sync

pm_runtime_disable

return err;


Am I missing something?

Thanks,

Quanyang


\
 
 \ /
  Last update: 2021-04-09 03:34    [W:0.074 / U:2.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site