[PATCH v2 1/2] [media] exynos-gsc: Fix unbalanced pm_runtime_enable() error

[PATCH v2 1/2] [media] exynos-gsc: Fix unbalanced pm_runtime_enable() error

[Javier Martinez Canillas]

Commit a006c04e6218 ("[media] exynos-gsc: Fixup clock management at
->remove()") changed the driver's .remove function logic to fist do
a pm_runtime_get_sync() to make sure the device is powered before
attempting to gate the gsc clock.

But the commit also removed a pm_runtime_disable() call that leads
to an unbalanced pm_runtime_enable() error if the driver is removed
and re-probed:

exynos-gsc 13e00000.video-scaler: Unbalanced pm_runtime_enable!
exynos-gsc 13e10000.video-scaler: Unbalanced pm_runtime_enable!

Fixes: a006c04e6218 ("[media] exynos-gsc: Fixup clock management at ->remove()")
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>

---

Changes in v2:
  - Added Marek Szyprowski's Acked-by tag.

 drivers/media/platform/exynos-gsc/gsc-core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c
index cbf75b6194b4..83272f10722d 100644
--- a/drivers/media/platform/exynos-gsc/gsc-core.c
+++ b/drivers/media/platform/exynos-gsc/gsc-core.c
@@ -1118,6 +1118,7 @@ static int gsc_remove(struct platform_device *pdev)
 		clk_disable_unprepare(gsc->clock[i]);
 
 	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
 
 	dev_dbg(&pdev->dev, "%s driver unloaded\n", pdev->name);
 	return 0;
-- 
2.7.4

[PATCH v2 2/2] [media] exynos-gsc: Only reset the GSC HW on probe() if !CONFIG_PM

[Javier Martinez Canillas]

Commit 15f90ab57acc ("[media] exynos-gsc: Make driver functional when
CONFIG_PM is unset") removed the implicit dependency that the driver
had with CONFIG_PM, since it relied on the config option to be enabled.

In order to work with !CONFIG_PM, the GSC reset logic that happens in
the runtime resume callback had to be executed on the probe function.

But there's no need to do this if CONFIG_PM is enabled, since in this
case the runtime PM resume callback will be called by VIDIOC_STREAMON
ioctl, so the resume handler will call the GSC HW reset function.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>

---

I-ve only tested with CONFIG_PM enabled since my Exynos5422 Odroid
XU4 board fails to boot when the config option is disabled.

Best regards,
Javier

Changes in v2:
 - Remove the Fixes tag and reword the commit message after feedback
   from Marek Szyprowski.

 drivers/media/platform/exynos-gsc/gsc-core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/exynos-gsc/gsc-core.c b/drivers/media/platform/exynos-gsc/gsc-core.c
index 83272f10722d..42e1e09ea915 100644
--- a/drivers/media/platform/exynos-gsc/gsc-core.c
+++ b/drivers/media/platform/exynos-gsc/gsc-core.c
@@ -1083,8 +1083,10 @@ static int gsc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, gsc);
 
-	gsc_hw_set_sw_reset(gsc);
-	gsc_wait_reset(gsc);
+	if (!IS_ENABLED(CONFIG_PM)) {
+		gsc_hw_set_sw_reset(gsc);
+		gsc_wait_reset(gsc);
+	}
 
 	vb2_dma_contig_set_max_seg_size(dev, DMA_BIT_MASK(32));
 
-- 
2.7.4

Re: [PATCH v2 2/2] [media] exynos-gsc: Only reset the GSC HW on probe() if !CONFIG_PM

[Javier Martinez Canillas]

Hello,

On 01/19/2017 07:36 PM, Javier Martinez Canillas wrote:
> Commit 15f90ab57acc ("[media] exynos-gsc: Make driver functional when
> CONFIG_PM is unset") removed the implicit dependency that the driver
> had with CONFIG_PM, since it relied on the config option to be enabled.
> 
> In order to work with !CONFIG_PM, the GSC reset logic that happens in
> the runtime resume callback had to be executed on the probe function.
> 
> But there's no need to do this if CONFIG_PM is enabled, since in this
> case the runtime PM resume callback will be called by VIDIOC_STREAMON
> ioctl, so the resume handler will call the GSC HW reset function.
> 
> Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
> 

Please ignore this patch as suggested by Marek in other thread.

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America