Re: [PATCH] [v3] spi: spi-zynqmp-gqspi: Fix runtime PM imbalance in zynqmp_qspi_probe

[quanyang.wang]

Hi Dinghao,

On 4/15/21 3:17 PM, 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.
Fixes: 9e3a000362aec ("spi: zynqmp: Add pm runtime support")
Signed-off-by: Dinghao Liu <dinghao....@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.

v3: - Add fix tag.
       Add a return value check against pm_runtime_get_sync().
       Move pm_runtime_{mark_last_busy & put_autosuspend} to the
       end of current function.
---
  drivers/spi/spi-zynqmp-gqspi.c | 12 ++++++++++--
  1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index c8fa6ee18ae7..781ef3fc76e2 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -1160,11 +1160,14 @@ 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);
+
+       ret = pm_runtime_get_sync(&pdev->dev);
+       if (ret < 0)
+               goto clk_dis_all;

Would you please add some error info output here? Just like:

+       if (ret < 0) {
+               dev_err(&pdev->dev, "failed to pm_runtime_get_sync: 
%d\n", ret);
+               goto clk_dis_all;
+       }
Because sometimes it is very helpful to analyse probe failure.

Thanks,

Quanyang

+
        /* QSPI controller initializations */
        zynqmp_qspi_init_hw(xqspi);
  
-	pm_runtime_mark_last_busy(&pdev->dev);
-       pm_runtime_put_autosuspend(&pdev->dev);
        xqspi->irq = platform_get_irq(pdev, 0);
        if (xqspi->irq <= 0) {
                ret = -ENXIO;
@@ -1187,6 +1190,7 @@ 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) {
@@ -1194,9 +1198,13 @@ static int zynqmp_qspi_probe(struct platform_device 
*pdev)
                goto clk_dis_all;
        }
  
+	pm_runtime_mark_last_busy(&pdev->dev);
+       pm_runtime_put_autosuspend(&pdev->dev);
+
        return 0;
  
  clk_dis_all:
+       pm_runtime_put_sync(&pdev->dev);
        pm_runtime_set_suspended(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
        clk_disable_unprepare(xqspi->refclk);