[PATCH] [v4] spi: spi-zynqmp-gqspi: Fix runtime PM imbalance in zynqmp_qspi_probe

[PATCH] [v4] spi: spi-zynqmp-gqspi: Fix runtime PM imbalance in zynqmp_qspi_probe

[Dinghao Liu]

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.liu@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.

v4: - Add error message on failure of pm_runtime_get_sync().
---
 drivers/spi/spi-zynqmp-gqspi.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index c8fa6ee18ae7..38f3ddd3ea7c 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -1160,11 +1160,16 @@ 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) {
+		dev_err(&pdev->dev, "Failed to pm_runtime_get_sync: %d\n", ret);
+		goto clk_dis_all;
+	}
+
 	/* 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 +1192,7 @@ 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 +1200,13 @@ 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);
-- 
2.17.1

Re: [PATCH] [v4] spi: spi-zynqmp-gqspi: Fix runtime PM imbalance in zynqmp_qspi_probe

[quanyang.wang]

On 4/15/21 3:46 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.liu@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.
>
> v4: - Add error message on failure of pm_runtime_get_sync().
> ---
>   drivers/spi/spi-zynqmp-gqspi.c | 14 ++++++++++++--
>   1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
> index c8fa6ee18ae7..38f3ddd3ea7c 100644
> --- a/drivers/spi/spi-zynqmp-gqspi.c
> +++ b/drivers/spi/spi-zynqmp-gqspi.c
> @@ -1160,11 +1160,16 @@ 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) {
> +		dev_err(&pdev->dev, "Failed to pm_runtime_get_sync: %d\n", ret);
> +		goto clk_dis_all;
> +	}
> +
>   	/* 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 +1192,7 @@ 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 +1200,13 @@ 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);

Test this patch at zcu102 board:

root@xilinx-zynqmp:~# dmesg | grep domain2
[    0.905407] zynqmp_gpd_attach_dev() ff0f0000.spi attached to domain2 
domain
[    0.912390] zynqmp_gpd_power_on() Powered on domain2 domain
[    4.350331] zynqmp_gpd_power_off() Powered off domain2 domain
root@xilinx-zynqmp:~# flash_erase /dev/mtd3 0 0
Erasing 4 Kibyte @ 0 --  0 % complete [  153.125894] 
zynqmp_gpd_power_on() Powered on domain2 domain
Erasing 4 Kibyte @ 2e8000 -- 49 % complete [  156.134884] 
zynqmp_gpd_power_off() Powered off domain2 domain
[  156.142648] zynqmp_gpd_power_on() Powered on domain2 domain
Erasing 4 Kibyte @ 5d5000 -- 99 % complete [  159.148329] 
zynqmp_gpd_power_off() Powered off domain2 domain
[  159.154579] zynqmp_gpd_power_on() Powered on domain2 domain
Erasing 4 Kibyte @ 5df000 -- 100 % complete
root@xilinx-zynqmp:~# [  162.910329] zynqmp_gpd_power_off() Powered off 
domain2 domain

pm_runtime works now. So

Tested-by: Quanyang Wang <quanyang.wang@windriver.com>

Regards,

Quanyang

Re: [PATCH] [v4] spi: spi-zynqmp-gqspi: Fix runtime PM imbalance in zynqmp_qspi_probe

[Mark Brown]

On Thu, 15 Apr 2021 15:46:44 +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.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: spi-zynqmp-gqspi: Fix runtime PM imbalance in zynqmp_qspi_probe
      commit: 58eaa7b2d07d3c25e1068b0bf42ca7e7464f4bca

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark