[PATCH] [v2] spi: spi-zynqmp-gqspi: Fix runtime PM imbalance in zynqmp_qspi_probe

[dinghao.liu at zju.edu.cn]

> Hi Dinghao,
> On Mon, Apr 12, 2021 at 03:31:54PM +0800, Dinghao Liu wrote:
> > There is a PM usage counter decrement after zynqmp_qspi_init_hw()
> > without any refcount increment, which leads to refcount leak.Add
> > a refcount increment to balance the refcount. Also set
> > auto_runtime_pm to resume suspended spi controller.
> > 
> > Signed-off-by: Dinghao Liu <dinghao.liu at zju.edu.cn>
> > ---
> > changelog:
> > 
> > v2: - Add a refcount increment to fix refcout leak instead of the
> >       refcount decrement on error.
> >       Set ctlr->auto_runtime_pm = true.
> > ---
> >  drivers/spi/spi-zynqmp-gqspi.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
> > index c8fa6ee18ae7..8b21c7b0e7eb 100644
> > --- a/drivers/spi/spi-zynqmp-gqspi.c
> > +++ b/drivers/spi/spi-zynqmp-gqspi.c
> > @@ -1160,6 +1160,7 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
> >  	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
> >  	pm_runtime_set_active(&pdev->dev);
> >  	pm_runtime_enable(&pdev->dev);
> > +	pm_runtime_get_sync(&pdev->dev);
> Please check the return value here, if ret is "< 0", goto error label,
> and a pm_runtime_put_sync is needed in error label
> >  	/* QSPI controller initializations */
> >  	zynqmp_qspi_init_hw(xqspi);
> >  
> > @@ -1187,6 +1188,7 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
> >  	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD |
> >  			    SPI_TX_DUAL | SPI_TX_QUAD;
> >  	ctlr->dev.of_node = np;
> > +	ctlr->auto_runtime_pm = true;
> >  
> >  	ret = devm_spi_register_controller(&pdev->dev, ctlr);
> >  	if (ret) {
> These 2 function
>      pm_runtime_mark_last_busy(&pdev->dev);
>       pm_runtime_put_autosuspend(&pdev->dev);
> are the last operations in probe function since if they runs,
> spi_controller will enter suspend state and disable clks after 3s
> passing. So please move them just before "return 0".
> 
> And would you please cc me when you send V3? I am preparing to send a patch series
> to fix clk and suspend/resume issues which bases on the pm_runtime issue.
> 

Thanks for your advice and I will send a new patch soon.

Regards,
Dinghao