[PATCH 00/78] media: use pm_runtime_resume_and_get() instead of pm_runtime_get_sync()

[PATCH 00/78] media: use pm_runtime_resume_and_get() instead of pm_runtime_get_sync()

[Mauro Carvalho Chehab]

During the review of the patches from unm.edu, one of the patterns
I noticed is the amount of patches trying to fix pm_runtime_get_sync()
calls.

On contrary of the common sense that a foo_get() function will
only increment the usage on success,  pm_runtime_get_sync()
increments it unconditionally.

Due to that, there are bugs on lots of places, that ended being
gradually fixed, but, still there are a few places on media where
this is still broken.

Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
added a new method to does a pm_runtime get, which increments
the usage count only on success.

This series replace all places where the old  pm_runtime_get_sync()
is called, using  pm_runtime_resume_and_get() instead.

This should help to avoid future mistakes like that, as people
tend to use the existing drivers as examples for newer ones.

compile-tested only.

Mauro Carvalho Chehab (78):
  media: atmel: properly get pm_runtime
  media: marvel-ccic: fix some issues when getting pm_runtime
  media: mdk-mdp: fix pm_runtime_get_sync() usage count
  media: rcar_fdp1: fix  usage count
  media: mdk-mdp: fix pm_runtime_get_sync() usage count
  media: renesas-ceu: fix pm_runtime_get_sync() usage count
  media: s5p: fix pm_runtime_get_sync() usage count
  media: am437x:: fix pm_runtime_get_sync() usage count
  media: sh_vou: fix pm_runtime_get_sync() usage count
  media: sti/hva: use pm_runtime_resume_and_get()
  staging: media: rkvdec: fix pm_runtime_get_sync() usage count
  staging: media: atomisp_fops: use pm_runtime_resume_and_get()
  staging: media: hantro_drv: use pm_runtime_resume_and_get()
  staging: media: imx7-mipi-csis: use pm_runtime_resume_and_get()
  staging: media: ipu3: use pm_runtime_resume_and_get()
  staging: media: cedrus_video: use pm_runtime_resume_and_get()
  staging: media: vde: use pm_runtime_resume_and_get()
  staging: media: csi: use pm_runtime_resume_and_get()
  staging: media: vi: use pm_runtime_resume_and_get()
  media: mtk-vcodec: fix pm_runtime_get_sync() usage count
  media: s5p-jpeg: fix pm_runtime_get_sync() usage count
  media: delta-v4l2: fix pm_runtime_get_sync() usage count
  media: sun8i_rotate: fix pm_runtime_get_sync() usage count
  media: i2c: ak7375: use pm_runtime_resume_and_get()
  media: i2c: ccs-core: use pm_runtime_resume_and_get()
  media: i2c: dw9714: use pm_runtime_resume_and_get()
  media: i2c: dw9768: use pm_runtime_resume_and_get()
  media: i2c: dw9807-vcm: use pm_runtime_resume_and_get()
  media: i2c: hi556: use pm_runtime_resume_and_get()
  media: i2c: imx214: use pm_runtime_resume_and_get()
  media: i2c: imx219: use pm_runtime_resume_and_get()
  media: i2c: imx258: use pm_runtime_resume_and_get()
  media: i2c: imx274: use pm_runtime_resume_and_get()
  media: i2c: imx290: use pm_runtime_resume_and_get()
  media: i2c: imx319: use pm_runtime_resume_and_get()
  media: i2c: imx334: use pm_runtime_resume_and_get()
  media: i2c: imx355: use pm_runtime_resume_and_get()
  media: i2c: mt9m001: use pm_runtime_resume_and_get()
  media: i2c: ov02a10: use pm_runtime_resume_and_get()
  media: i2c: ov13858: use pm_runtime_resume_and_get()
  media: i2c: ov2659: use pm_runtime_resume_and_get()
  media: i2c: ov2685: use pm_runtime_resume_and_get()
  media: i2c: ov2740: use pm_runtime_resume_and_get()
  media: i2c: ov5647: use pm_runtime_resume_and_get()
  media: i2c: ov5648: use pm_runtime_resume_and_get()
  media: i2c: ov5670: use pm_runtime_resume_and_get()
  media: i2c: ov5675: use pm_runtime_resume_and_get()
  media: i2c: ov5695: use pm_runtime_resume_and_get()
  media: i2c: ov7740: use pm_runtime_resume_and_get()
  media: i2c: ov8856: use pm_runtime_resume_and_get()
  media: i2c: ov8865: use pm_runtime_resume_and_get()
  media: i2c: ov9734: use pm_runtime_resume_and_get()
  media: i2c: tvp5150: use pm_runtime_resume_and_get()
  media: i2c: video-i2c: use pm_runtime_resume_and_get()
  media: ipu3: use pm_runtime_resume_and_get()
  media: coda: use pm_runtime_resume_and_get()
  media: exynos4-is: use pm_runtime_resume_and_get()
  media: exynos-gsc: use pm_runtime_resume_and_get()
  media: mtk-jpeg: use pm_runtime_resume_and_get()
  media: camss-csid: use pm_runtime_resume_and_get()
  media: camss-csiphy: use pm_runtime_resume_and_get()
  media: camss-ispif: use pm_runtime_resume_and_get()
  media: camss-vfe: use pm_runtime_resume_and_get()
  media: core: use pm_runtime_resume_and_get()
  media: pm_helpers: use pm_runtime_resume_and_get()
  media: vdec: use pm_runtime_resume_and_get()
  media: venc: use pm_runtime_resume_and_get()
  media: rcar-fcp: use pm_runtime_resume_and_get()
  media: rcar-vin: use pm_runtime_resume_and_get()
  media: rga-buf: use pm_runtime_resume_and_get()
  media: rkisp1-capture: use pm_runtime_resume_and_get()
  media: s3c-camif: use pm_runtime_resume_and_get()
  media: s5p-mfc: use pm_runtime_resume_and_get()
  media: bdisp-v4l2: use pm_runtime_resume_and_get()
  media: stm32: use pm_runtime_resume_and_get()
  media: sun4i_v4l2: use pm_runtime_resume_and_get()
  media: ti-vpe: use pm_runtime_resume_and_get()
  media: vsp1: use pm_runtime_resume_and_get()

 drivers/media/cec/platform/s5p/s5p_cec.c      |  5 +++-
 drivers/media/i2c/ak7375.c                    | 10 +------
 drivers/media/i2c/ccs/ccs-core.c              | 11 ++++----
 drivers/media/i2c/dw9714.c                    | 10 +------
 drivers/media/i2c/dw9768.c                    | 10 +------
 drivers/media/i2c/dw9807-vcm.c                | 10 +------
 drivers/media/i2c/hi556.c                     |  3 +--
 drivers/media/i2c/imx214.c                    |  6 ++---
 drivers/media/i2c/imx219.c                    |  6 ++---
 drivers/media/i2c/imx258.c                    |  6 ++---
 drivers/media/i2c/imx274.c                    |  3 +--
 drivers/media/i2c/imx290.c                    |  6 ++---
 drivers/media/i2c/imx319.c                    |  6 ++---
 drivers/media/i2c/imx334.c                    |  5 ++--
 drivers/media/i2c/imx355.c                    |  6 ++---
 drivers/media/i2c/mt9m001.c                   |  7 ++---
 drivers/media/i2c/ov02a10.c                   |  6 ++---
 drivers/media/i2c/ov13858.c                   |  6 ++---
 drivers/media/i2c/ov2659.c                    |  6 ++---
 drivers/media/i2c/ov2685.c                    |  7 +++--
 drivers/media/i2c/ov2740.c                    |  6 ++---
 drivers/media/i2c/ov5647.c                    |  9 ++++---
 drivers/media/i2c/ov5648.c                    |  6 ++---
 drivers/media/i2c/ov5670.c                    |  6 ++---
 drivers/media/i2c/ov5675.c                    |  3 +--
 drivers/media/i2c/ov5695.c                    |  6 ++---
 drivers/media/i2c/ov7740.c                    |  8 +++---
 drivers/media/i2c/ov8856.c                    |  3 +--
 drivers/media/i2c/ov8865.c                    |  6 ++---
 drivers/media/i2c/ov9734.c                    |  3 +--
 drivers/media/i2c/tvp5150.c                   | 16 +++---------
 drivers/media/i2c/video-i2c.c                 | 14 ++++------
 drivers/media/pci/intel/ipu3/ipu3-cio2-main.c |  3 +--
 drivers/media/platform/am437x/am437x-vpfe.c   | 10 ++++---
 drivers/media/platform/atmel/atmel-isc-base.c | 26 ++++++++++++++-----
 drivers/media/platform/atmel/atmel-isi.c      | 19 +++++++++++---
 drivers/media/platform/coda/coda-common.c     |  2 +-
 drivers/media/platform/exynos-gsc/gsc-core.c  |  3 +--
 drivers/media/platform/exynos-gsc/gsc-m2m.c   |  2 +-
 .../media/platform/exynos4-is/fimc-capture.c  |  6 ++---
 drivers/media/platform/exynos4-is/fimc-is.c   |  3 ++-
 .../platform/exynos4-is/fimc-isp-video.c      |  3 +--
 drivers/media/platform/exynos4-is/fimc-isp.c  |  7 +++--
 drivers/media/platform/exynos4-is/fimc-lite.c |  5 ++--
 drivers/media/platform/exynos4-is/fimc-m2m.c  |  2 +-
 drivers/media/platform/exynos4-is/media-dev.c |  8 +++---
 drivers/media/platform/exynos4-is/mipi-csis.c |  5 ++--
 .../media/platform/marvell-ccic/mcam-core.c   |  9 +++++--
 .../media/platform/mtk-jpeg/mtk_jpeg_core.c   |  4 +--
 drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c  |  6 ++---
 .../platform/mtk-vcodec/mtk_vcodec_dec_pm.c   |  4 +--
 .../media/platform/qcom/camss/camss-csid.c    |  6 ++---
 .../media/platform/qcom/camss/camss-csiphy.c  |  6 ++---
 .../media/platform/qcom/camss/camss-ispif.c   |  6 ++---
 drivers/media/platform/qcom/camss/camss-vfe.c |  5 ++--
 drivers/media/platform/qcom/venus/core.c      | 19 +++++++-------
 .../media/platform/qcom/venus/pm_helpers.c    | 10 +++----
 drivers/media/platform/qcom/venus/vdec.c      |  4 +--
 drivers/media/platform/qcom/venus/venc.c      |  5 ++--
 drivers/media/platform/rcar-fcp.c             |  6 ++---
 drivers/media/platform/rcar-vin/rcar-csi2.c   |  2 +-
 drivers/media/platform/rcar-vin/rcar-dma.c    |  6 ++---
 drivers/media/platform/rcar-vin/rcar-v4l2.c   |  6 ++---
 drivers/media/platform/rcar_fdp1.c            | 12 +++++++--
 drivers/media/platform/renesas-ceu.c          |  5 +++-
 drivers/media/platform/rockchip/rga/rga-buf.c |  3 +--
 drivers/media/platform/rockchip/rga/rga.c     |  4 ++-
 .../platform/rockchip/rkisp1/rkisp1-capture.c |  3 +--
 .../media/platform/s3c-camif/camif-capture.c  |  5 ++--
 drivers/media/platform/s3c-camif/camif-core.c |  5 ++--
 drivers/media/platform/s5p-jpeg/jpeg-core.c   |  2 +-
 drivers/media/platform/s5p-mfc/s5p_mfc_pm.c   |  6 ++---
 drivers/media/platform/sh_vou.c               |  6 ++++-
 drivers/media/platform/sti/bdisp/bdisp-v4l2.c |  7 ++---
 drivers/media/platform/sti/delta/delta-v4l2.c |  4 +--
 drivers/media/platform/sti/hva/hva-hw.c       | 17 ++++++------
 drivers/media/platform/stm32/stm32-dcmi.c     |  5 ++--
 .../platform/sunxi/sun4i-csi/sun4i_v4l2.c     |  7 +++--
 .../sunxi/sun8i-rotate/sun8i_rotate.c         |  2 +-
 drivers/media/platform/ti-vpe/cal-video.c     |  4 ++-
 drivers/media/platform/ti-vpe/cal.c           |  8 +++---
 drivers/media/platform/ti-vpe/vpe.c           |  4 +--
 drivers/media/platform/vsp1/vsp1_drv.c        |  6 ++---
 .../staging/media/atomisp/pci/atomisp_fops.c  |  6 ++---
 drivers/staging/media/hantro/hantro_drv.c     |  2 +-
 drivers/staging/media/imx/imx7-mipi-csis.c    |  7 +++--
 drivers/staging/media/ipu3/ipu3.c             |  3 +--
 drivers/staging/media/rkvdec/rkvdec.c         |  2 +-
 .../staging/media/sunxi/cedrus/cedrus_video.c |  6 ++---
 drivers/staging/media/tegra-vde/vde.c         | 16 +++++++-----
 drivers/staging/media/tegra-video/csi.c       |  3 +--
 drivers/staging/media/tegra-video/vi.c        |  3 +--
 92 files changed, 270 insertions(+), 322 deletions(-)

-- 
2.30.2


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[PATCH 11/78] staging: media: rkvdec: fix pm_runtime_get_sync() usage count

[Mauro Carvalho Chehab]

The pm_runtime_get_sync() internally increments the
dev->power.usage_count without decrementing it, even on errors.
replace it by the new pm_runtime_resume_and_get(), introduced by:
commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
in order to properly decrement the usage counter and avoid memory
leaks.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/rkvdec/rkvdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/media/rkvdec/rkvdec.c b/drivers/staging/media/rkvdec/rkvdec.c
index d821661d30f3..8c17615f3a7a 100644
--- a/drivers/staging/media/rkvdec/rkvdec.c
+++ b/drivers/staging/media/rkvdec/rkvdec.c
@@ -658,7 +658,7 @@ static void rkvdec_device_run(void *priv)
 	if (WARN_ON(!desc))
 		return;
 
-	ret = pm_runtime_get_sync(rkvdec->dev);
+	ret = pm_runtime_resume_and_get(rkvdec->dev);
 	if (ret < 0) {
 		rkvdec_job_finish_no_pm(ctx, VB2_BUF_STATE_ERROR);
 		return;
-- 
2.30.2

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[PATCH 12/78] staging: media: atomisp_fops: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
added pm_runtime_resume_and_get() in order to automatically handle
dev->power.usage_count decrement on errors.

Use the new API, in order to cleanup the error check logic.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/atomisp/pci/atomisp_fops.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_fops.c b/drivers/staging/media/atomisp/pci/atomisp_fops.c
index f1e6b2597853..26d05474a035 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_fops.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_fops.c
@@ -837,7 +837,7 @@ static int atomisp_open(struct file *file)
 	}
 
 	/* runtime power management, turn on ISP */
-	ret = pm_runtime_get_sync(vdev->v4l2_dev->dev);
+	ret = pm_runtime_resume_and_get(vdev->v4l2_dev->dev);
 	if (ret < 0) {
 		dev_err(isp->dev, "Failed to power on device\n");
 		goto error;
@@ -881,9 +881,9 @@ static int atomisp_open(struct file *file)
 
 css_error:
 	atomisp_css_uninit(isp);
-error:
-	hmm_pool_unregister(HMM_POOL_TYPE_DYNAMIC);
 	pm_runtime_put(vdev->v4l2_dev->dev);
+error:
+	hmm_pool_unregister(HMM_POOL_TYPE_DYNAMIC);
 	rt_mutex_unlock(&isp->mutex);
 	return ret;
 }
-- 
2.30.2

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[PATCH 13/78] staging: media: hantro_drv: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
added pm_runtime_resume_and_get() in order to automatically handle
dev->power.usage_count decrement on errors.

Use the new API, in order to cleanup the error check logic.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/hantro/hantro_drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/media/hantro/hantro_drv.c b/drivers/staging/media/hantro/hantro_drv.c
index 595e82a82728..3147dcbebeb9 100644
--- a/drivers/staging/media/hantro/hantro_drv.c
+++ b/drivers/staging/media/hantro/hantro_drv.c
@@ -155,7 +155,7 @@ static void device_run(void *priv)
 	ret = clk_bulk_enable(ctx->dev->variant->num_clocks, ctx->dev->clocks);
 	if (ret)
 		goto err_cancel_job;
-	ret = pm_runtime_get_sync(ctx->dev->dev);
+	ret = pm_runtime_resume_and_get(ctx->dev->dev);
 	if (ret < 0)
 		goto err_cancel_job;
 
-- 
2.30.2

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[PATCH 14/78] staging: media: imx7-mipi-csis: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
added pm_runtime_resume_and_get() in order to automatically handle
dev->power.usage_count decrement on errors.

Use the new API, in order to cleanup the error check logic.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/imx/imx7-mipi-csis.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/media/imx/imx7-mipi-csis.c b/drivers/staging/media/imx/imx7-mipi-csis.c
index 025fdc488bd6..1dc680d94a46 100644
--- a/drivers/staging/media/imx/imx7-mipi-csis.c
+++ b/drivers/staging/media/imx/imx7-mipi-csis.c
@@ -695,11 +695,10 @@ static int mipi_csis_s_stream(struct v4l2_subdev *mipi_sd, int enable)
 
 		mipi_csis_clear_counters(state);
 
-		ret = pm_runtime_get_sync(&state->pdev->dev);
-		if (ret < 0) {
-			pm_runtime_put_noidle(&state->pdev->dev);
+		ret = pm_runtime_resume_and_get(&state->pdev->dev);
+		if (ret < 0)
 			return ret;
-		}
+
 		ret = v4l2_subdev_call(state->src_sd, core, s_power, 1);
 		if (ret < 0 && ret != -ENOIOCTLCMD)
 			goto done;
-- 
2.30.2

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[PATCH 15/78] staging: media: ipu3: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
added pm_runtime_resume_and_get() in order to automatically handle
dev->power.usage_count decrement on errors.

Use the new API, in order to cleanup the error check logic.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/ipu3/ipu3.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/staging/media/ipu3/ipu3.c b/drivers/staging/media/ipu3/ipu3.c
index ee1bba6bdcac..8e1e9e46e604 100644
--- a/drivers/staging/media/ipu3/ipu3.c
+++ b/drivers/staging/media/ipu3/ipu3.c
@@ -392,10 +392,9 @@ int imgu_s_stream(struct imgu_device *imgu, int enable)
 	}
 
 	/* Set Power */
-	r = pm_runtime_get_sync(dev);
+	r = pm_runtime_resume_and_get(dev);
 	if (r < 0) {
 		dev_err(dev, "failed to set imgu power\n");
-		pm_runtime_put(dev);
 		return r;
 	}
 
-- 
2.30.2

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[PATCH 16/78] staging: media: cedrus_video: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
added pm_runtime_resume_and_get() in order to automatically handle
dev->power.usage_count decrement on errors.

Use the new API, in order to cleanup the error check logic.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/sunxi/cedrus/cedrus_video.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_video.c b/drivers/staging/media/sunxi/cedrus/cedrus_video.c
index b62eb8e84057..9ddd789d0b1f 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus_video.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_video.c
@@ -490,11 +490,9 @@ static int cedrus_start_streaming(struct vb2_queue *vq, unsigned int count)
 	}
 
 	if (V4L2_TYPE_IS_OUTPUT(vq->type)) {
-		ret = pm_runtime_get_sync(dev->dev);
-		if (ret < 0) {
-			pm_runtime_put_noidle(dev->dev);
+		ret = pm_runtime_resume_and_get(dev->dev);
+		if (ret < 0)
 			goto err_cleanup;
-		}
 
 		if (dev->dec_ops[ctx->current_codec]->start) {
 			ret = dev->dec_ops[ctx->current_codec]->start(ctx);
-- 
2.30.2

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[PATCH 17/78] staging: media: vde: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
added pm_runtime_resume_and_get() in order to automatically handle
dev->power.usage_count decrement on errors.

Use the new API, in order to cleanup the error check logic.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/tegra-vde/vde.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/media/tegra-vde/vde.c b/drivers/staging/media/tegra-vde/vde.c
index 28845b5bafaf..8936f140a246 100644
--- a/drivers/staging/media/tegra-vde/vde.c
+++ b/drivers/staging/media/tegra-vde/vde.c
@@ -775,9 +775,9 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
 	if (ret)
 		goto release_dpb_frames;
 
-	ret = pm_runtime_get_sync(dev);
+	ret = pm_runtime_resume_and_get(dev);
 	if (ret < 0)
-		goto put_runtime_pm;
+		goto unlock;
 
 	/*
 	 * We rely on the VDE registers reset value, otherwise VDE
@@ -843,6 +843,8 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
 put_runtime_pm:
 	pm_runtime_mark_last_busy(dev);
 	pm_runtime_put_autosuspend(dev);
+
+unlock:
 	mutex_unlock(&vde->lock);
 
 release_dpb_frames:
@@ -1069,8 +1071,8 @@ static int tegra_vde_probe(struct platform_device *pdev)
 	 * power-cycle it in order to put hardware into a predictable lower
 	 * power state.
 	 */
-	pm_runtime_get_sync(dev);
-	pm_runtime_put(dev);
+	if (pm_runtime_resume_and_get(dev) >= 0)
+		pm_runtime_put(dev);
 
 	return 0;
 
@@ -1088,8 +1090,9 @@ static int tegra_vde_remove(struct platform_device *pdev)
 {
 	struct tegra_vde *vde = platform_get_drvdata(pdev);
 	struct device *dev = &pdev->dev;
+	int ret;
 
-	pm_runtime_get_sync(dev);
+	ret = pm_runtime_resume_and_get(dev);
 	pm_runtime_dont_use_autosuspend(dev);
 	pm_runtime_disable(dev);
 
@@ -1097,7 +1100,8 @@ static int tegra_vde_remove(struct platform_device *pdev)
 	 * Balance RPM state, the VDE power domain is left ON and hardware
 	 * is clock-gated. It's safe to reboot machine now.
 	 */
-	pm_runtime_put_noidle(dev);
+	if (ret >= 0)
+		pm_runtime_put_noidle(dev);
 	clk_disable_unprepare(vde->clk);
 
 	misc_deregister(&vde->miscdev);
-- 
2.30.2

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[PATCH 18/78] staging: media: csi: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
added pm_runtime_resume_and_get() in order to automatically handle
dev->power.usage_count decrement on errors.

Use the new API, in order to cleanup the error check logic.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/tegra-video/csi.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/staging/media/tegra-video/csi.c b/drivers/staging/media/tegra-video/csi.c
index 033a6935c26d..e938bf4c48b6 100644
--- a/drivers/staging/media/tegra-video/csi.c
+++ b/drivers/staging/media/tegra-video/csi.c
@@ -298,10 +298,9 @@ static int tegra_csi_enable_stream(struct v4l2_subdev *subdev)
 	struct tegra_csi *csi = csi_chan->csi;
 	int ret, err;
 
-	ret = pm_runtime_get_sync(csi->dev);
+	ret = pm_runtime_resume_and_get(csi->dev);
 	if (ret < 0) {
 		dev_err(csi->dev, "failed to get runtime PM: %d\n", ret);
-		pm_runtime_put_noidle(csi->dev);
 		return ret;
 	}
 
-- 
2.30.2

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[PATCH 19/78] staging: media: vi: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
added pm_runtime_resume_and_get() in order to automatically handle
dev->power.usage_count decrement on errors.

Use the new API, in order to cleanup the error check logic.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/tegra-video/vi.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/staging/media/tegra-video/vi.c b/drivers/staging/media/tegra-video/vi.c
index 7a09061cda57..1298740a9c6c 100644
--- a/drivers/staging/media/tegra-video/vi.c
+++ b/drivers/staging/media/tegra-video/vi.c
@@ -297,10 +297,9 @@ static int tegra_channel_start_streaming(struct vb2_queue *vq, u32 count)
 	struct tegra_vi_channel *chan = vb2_get_drv_priv(vq);
 	int ret;
 
-	ret = pm_runtime_get_sync(chan->vi->dev);
+	ret = pm_runtime_resume_and_get(chan->vi->dev);
 	if (ret < 0) {
 		dev_err(chan->vi->dev, "failed to get runtime PM: %d\n", ret);
-		pm_runtime_put_noidle(chan->vi->dev);
 		return ret;
 	}
 
-- 
2.30.2

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Re: [PATCH 17/78] staging: media: vde: use pm_runtime_resume_and_get()

[Dmitry Osipenko]

24.04.2021 09:44, Mauro Carvalho Chehab пишет:
> Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> added pm_runtime_resume_and_get() in order to automatically handle
> dev->power.usage_count decrement on errors.
> 
> Use the new API, in order to cleanup the error check logic.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> ---
>  drivers/staging/media/tegra-vde/vde.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/staging/media/tegra-vde/vde.c b/drivers/staging/media/tegra-vde/vde.c
> index 28845b5bafaf..8936f140a246 100644
> --- a/drivers/staging/media/tegra-vde/vde.c
> +++ b/drivers/staging/media/tegra-vde/vde.c
> @@ -775,9 +775,9 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>  	if (ret)
>  		goto release_dpb_frames;
>  
> -	ret = pm_runtime_get_sync(dev);
> +	ret = pm_runtime_resume_and_get(dev);
>  	if (ret < 0)
> -		goto put_runtime_pm;
> +		goto unlock;
>  
>  	/*
>  	 * We rely on the VDE registers reset value, otherwise VDE
> @@ -843,6 +843,8 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>  put_runtime_pm:
>  	pm_runtime_mark_last_busy(dev);
>  	pm_runtime_put_autosuspend(dev);
> +
> +unlock:
>  	mutex_unlock(&vde->lock);
>  
>  release_dpb_frames:
> @@ -1069,8 +1071,8 @@ static int tegra_vde_probe(struct platform_device *pdev)
>  	 * power-cycle it in order to put hardware into a predictable lower
>  	 * power state.
>  	 */
> -	pm_runtime_get_sync(dev);
> -	pm_runtime_put(dev);
> +	if (pm_runtime_resume_and_get(dev) >= 0)
> +		pm_runtime_put(dev);
>  
>  	return 0;
>  
> @@ -1088,8 +1090,9 @@ static int tegra_vde_remove(struct platform_device *pdev)
>  {
>  	struct tegra_vde *vde = platform_get_drvdata(pdev);
>  	struct device *dev = &pdev->dev;
> +	int ret;
>  
> -	pm_runtime_get_sync(dev);
> +	ret = pm_runtime_resume_and_get(dev);
>  	pm_runtime_dont_use_autosuspend(dev);
>  	pm_runtime_disable(dev);
>  
> @@ -1097,7 +1100,8 @@ static int tegra_vde_remove(struct platform_device *pdev)
>  	 * Balance RPM state, the VDE power domain is left ON and hardware
>  	 * is clock-gated. It's safe to reboot machine now.
>  	 */
> -	pm_runtime_put_noidle(dev);
> +	if (ret >= 0)
> +		pm_runtime_put_noidle(dev);
>  	clk_disable_unprepare(vde->clk);
>  
>  	misc_deregister(&vde->miscdev);
> 

Hello Mauro,

Thank you very much for the patch. It looks to me that the original
variant was a bit simpler, this patch adds more code lines without
changing the previous behaviour. Or am I missing something?
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Re: [PATCH 11/78] staging: media: rkvdec: fix pm_runtime_get_sync() usage count

[Ezequiel Garcia]

On Sat, 2021-04-24 at 08:44 +0200, Mauro Carvalho Chehab wrote:
> The pm_runtime_get_sync() internally increments the
> dev->power.usage_count without decrementing it, even on errors.
> replace it by the new pm_runtime_resume_and_get(), introduced by:
> commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> in order to properly decrement the usage counter and avoid memory
> leaks.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>

Thanks a lot for taking care of this.

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Re: [PATCH 13/78] staging: media: hantro_drv: use pm_runtime_resume_and_get()

[Ezequiel Garcia]

Hi Mauro,

On Sat, 2021-04-24 at 08:44 +0200, Mauro Carvalho Chehab wrote:
> Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> added pm_runtime_resume_and_get() in order to automatically handle
> dev->power.usage_count decrement on errors.
> 
> Use the new API, in order to cleanup the error check logic.
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> ---
>  drivers/staging/media/hantro/hantro_drv.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/media/hantro/hantro_drv.c b/drivers/staging/media/hantro/hantro_drv.c
> index 595e82a82728..3147dcbebeb9 100644
> --- a/drivers/staging/media/hantro/hantro_drv.c
> +++ b/drivers/staging/media/hantro/hantro_drv.c
> @@ -155,7 +155,7 @@ static void device_run(void *priv)
>         ret = clk_bulk_enable(ctx->dev->variant->num_clocks, ctx->dev->clocks);
>         if (ret)
>                 goto err_cancel_job;
> -       ret = pm_runtime_get_sync(ctx->dev->dev);
> +       ret = pm_runtime_resume_and_get(ctx->dev->dev);
>         if (ret < 0)
>                 goto err_cancel_job;
>  

Seems this one needs a different fix: err_cancel_job
will call hantro_job_finish which has a pm_runtime put.

Thanks,
Ezequiel 

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Re: [PATCH 14/78] staging: media: imx7-mipi-csis: use pm_runtime_resume_and_get()

[Rui Miguel Silva]

Hi Mauro,
On Sat Apr 24, 2021 at 7:44 AM WEST, Mauro Carvalho Chehab wrote:
> Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> added pm_runtime_resume_and_get() in order to automatically handle
> dev->power.usage_count decrement on errors.
>
> Use the new API, in order to cleanup the error check logic.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Thanks, looks good.

Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>

------
Cheers,
	 Rui
> ---
>  drivers/staging/media/imx/imx7-mipi-csis.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/staging/media/imx/imx7-mipi-csis.c b/drivers/staging/media/imx/imx7-mipi-csis.c
> index 025fdc488bd6..1dc680d94a46 100644
> --- a/drivers/staging/media/imx/imx7-mipi-csis.c
> +++ b/drivers/staging/media/imx/imx7-mipi-csis.c
> @@ -695,11 +695,10 @@ static int mipi_csis_s_stream(struct v4l2_subdev *mipi_sd, int enable)
>  
>  		mipi_csis_clear_counters(state);
>  
> -		ret = pm_runtime_get_sync(&state->pdev->dev);
> -		if (ret < 0) {
> -			pm_runtime_put_noidle(&state->pdev->dev);
> +		ret = pm_runtime_resume_and_get(&state->pdev->dev);
> +		if (ret < 0)
>  			return ret;
> -		}
> +
>  		ret = v4l2_subdev_call(state->src_sd, core, s_power, 1);
>  		if (ret < 0 && ret != -ENOIOCTLCMD)
>  			goto done;
> -- 
> 2.30.2


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Re: [PATCH 13/78] staging: media: hantro_drv: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Em Sat, 24 Apr 2021 20:23:53 -0300
Ezequiel Garcia <ezequiel@collabora.com> escreveu:

> Hi Mauro,
> 
> On Sat, 2021-04-24 at 08:44 +0200, Mauro Carvalho Chehab wrote:
> > Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> > added pm_runtime_resume_and_get() in order to automatically handle
> > dev->power.usage_count decrement on errors.
> > 
> > Use the new API, in order to cleanup the error check logic.
> > 
> > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> > ---
> >  drivers/staging/media/hantro/hantro_drv.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/staging/media/hantro/hantro_drv.c b/drivers/staging/media/hantro/hantro_drv.c
> > index 595e82a82728..3147dcbebeb9 100644
> > --- a/drivers/staging/media/hantro/hantro_drv.c
> > +++ b/drivers/staging/media/hantro/hantro_drv.c
> > @@ -155,7 +155,7 @@ static void device_run(void *priv)
> >         ret = clk_bulk_enable(ctx->dev->variant->num_clocks, ctx->dev->clocks);
> >         if (ret)
> >                 goto err_cancel_job;
> > -       ret = pm_runtime_get_sync(ctx->dev->dev);
> > +       ret = pm_runtime_resume_and_get(ctx->dev->dev);
> >         if (ret < 0)
> >                 goto err_cancel_job;
> >    
> 
> Seems this one needs a different fix: err_cancel_job
> will call hantro_job_finish which has a pm_runtime put.

Good point. Thanks for reviewing it!

It sounds that this is a place where the best seems
to keep using pm_runtime_get_sync(), but let's at least add a
comment explaining why it should be kept here. This should
help to avoid people to copy-and-paste the code on situations
where pm_runtime_resume_and_get() should be used instead.

See enclosed patch.

Thanks,
Mauro

[PATCH] media: hantro: document the usage of pm_runtime_get_sync()

Despite other *_get()/*_put() functions, where usage count is
incremented only if not errors, the pm_runtime_get_sync() has
a different behavior, incrementing the counter *even* on
errors.

That's an error prone behavior, as people often forget to
decrement the usage counter.

However, the hantro driver depends on this behavior, as it
will decrement the usage_count unconditionally at the m2m
job finish time, which makes sense.

So, intead of using the pm_runtime_resume_and_get() that
would decrement the counter on error, keep the current
API, but add a documentation explaining the rationale for
keep using pm_runtime_get_sync().

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/staging/media/hantro/hantro_drv.c b/drivers/staging/media/hantro/hantro_drv.c
index 595e82a82728..96f940c1c85c 100644
--- a/drivers/staging/media/hantro/hantro_drv.c
+++ b/drivers/staging/media/hantro/hantro_drv.c
@@ -155,6 +155,13 @@ static void device_run(void *priv)
 	ret = clk_bulk_enable(ctx->dev->variant->num_clocks, ctx->dev->clocks);
 	if (ret)
 		goto err_cancel_job;
+
+	/*
+	 * The pm_runtime_get_sync() will increment dev->power.usage_count,
+	 * even on errors. That's the expected behavior here, since the
+	 * hantro_job_finish() function at the error handling code
+	 * will internally call pm_runtime_put_autosuspend().
+	 */
 	ret = pm_runtime_get_sync(ctx->dev->dev);
 	if (ret < 0)
 		goto err_cancel_job;


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Re: [PATCH 13/78] staging: media: hantro_drv: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Em Mon, 26 Apr 2021 14:33:27 +0200
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> escreveu:

> Em Sat, 24 Apr 2021 20:23:53 -0300
> Ezequiel Garcia <ezequiel@collabora.com> escreveu:
> 
> > Hi Mauro,
> > 
> > On Sat, 2021-04-24 at 08:44 +0200, Mauro Carvalho Chehab wrote:  
> > > Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> > > added pm_runtime_resume_and_get() in order to automatically handle
> > > dev->power.usage_count decrement on errors.
> > > 
> > > Use the new API, in order to cleanup the error check logic.
> > > 
> > > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> > > ---
> > >  drivers/staging/media/hantro/hantro_drv.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/staging/media/hantro/hantro_drv.c b/drivers/staging/media/hantro/hantro_drv.c
> > > index 595e82a82728..3147dcbebeb9 100644
> > > --- a/drivers/staging/media/hantro/hantro_drv.c
> > > +++ b/drivers/staging/media/hantro/hantro_drv.c
> > > @@ -155,7 +155,7 @@ static void device_run(void *priv)
> > >         ret = clk_bulk_enable(ctx->dev->variant->num_clocks, ctx->dev->clocks);
> > >         if (ret)
> > >                 goto err_cancel_job;
> > > -       ret = pm_runtime_get_sync(ctx->dev->dev);
> > > +       ret = pm_runtime_resume_and_get(ctx->dev->dev);
> > >         if (ret < 0)
> > >                 goto err_cancel_job;
> > >      
> > 
> > Seems this one needs a different fix: err_cancel_job
> > will call hantro_job_finish which has a pm_runtime put.  
> 
> Good point. Thanks for reviewing it!
> 
> It sounds that this is a place where the best seems
> to keep using pm_runtime_get_sync(), but let's at least add a
> comment explaining why it should be kept here. This should
> help to avoid people to copy-and-paste the code on situations
> where pm_runtime_resume_and_get() should be used instead.
> 
> See enclosed patch.
> 
> Thanks,
> Mauro
> 
> [PATCH] media: hantro: document the usage of pm_runtime_get_sync()
> 
> Despite other *_get()/*_put() functions, where usage count is
> incremented only if not errors, the pm_runtime_get_sync() has
> a different behavior, incrementing the counter *even* on
> errors.
> 
> That's an error prone behavior, as people often forget to
> decrement the usage counter.
> 
> However, the hantro driver depends on this behavior, as it
> will decrement the usage_count unconditionally at the m2m
> job finish time, which makes sense.
> 
> So, intead of using the pm_runtime_resume_and_get() that
> would decrement the counter on error, keep the current
> API, but add a documentation explaining the rationale for
> keep using pm_runtime_get_sync().
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Hmm... maybe it can, instead, use the same solution as the
rkvdec driver does, having a job_finish_no_pm() plus the normal
job_finish().

What do you think?

Regards,
Mauro

> 
> diff --git a/drivers/staging/media/hantro/hantro_drv.c b/drivers/staging/media/hantro/hantro_drv.c
> index 595e82a82728..96f940c1c85c 100644
> --- a/drivers/staging/media/hantro/hantro_drv.c
> +++ b/drivers/staging/media/hantro/hantro_drv.c
> @@ -155,6 +155,13 @@ static void device_run(void *priv)
>  	ret = clk_bulk_enable(ctx->dev->variant->num_clocks, ctx->dev->clocks);
>  	if (ret)
>  		goto err_cancel_job;
> +
> +	/*
> +	 * The pm_runtime_get_sync() will increment dev->power.usage_count,
> +	 * even on errors. That's the expected behavior here, since the
> +	 * hantro_job_finish() function at the error handling code
> +	 * will internally call pm_runtime_put_autosuspend().
> +	 */
>  	ret = pm_runtime_get_sync(ctx->dev->dev);
>  	if (ret < 0)
>  		goto err_cancel_job;
> 
> 



Thanks,
Mauro
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Re: [PATCH 17/78] staging: media: vde: use pm_runtime_resume_and_get()

[Mauro Carvalho Chehab]

Hi Dmitry,

Em Sat, 24 Apr 2021 10:35:22 +0300
Dmitry Osipenko <digetx@gmail.com> escreveu:

> 24.04.2021 09:44, Mauro Carvalho Chehab пишет:
> > Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> > added pm_runtime_resume_and_get() in order to automatically handle
> > dev->power.usage_count decrement on errors.
> > 
> > Use the new API, in order to cleanup the error check logic.
> > 
> > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> > ---
> >  drivers/staging/media/tegra-vde/vde.c | 16 ++++++++++------
> >  1 file changed, 10 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/staging/media/tegra-vde/vde.c b/drivers/staging/media/tegra-vde/vde.c
> > index 28845b5bafaf..8936f140a246 100644
> > --- a/drivers/staging/media/tegra-vde/vde.c
> > +++ b/drivers/staging/media/tegra-vde/vde.c
> > @@ -775,9 +775,9 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
> >  	if (ret)
> >  		goto release_dpb_frames;
> >  
> > -	ret = pm_runtime_get_sync(dev);
> > +	ret = pm_runtime_resume_and_get(dev);
> >  	if (ret < 0)
> > -		goto put_runtime_pm;
> > +		goto unlock;
> >  
> >  	/*
> >  	 * We rely on the VDE registers reset value, otherwise VDE
> > @@ -843,6 +843,8 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
> >  put_runtime_pm:
> >  	pm_runtime_mark_last_busy(dev);
> >  	pm_runtime_put_autosuspend(dev);
> > +
> > +unlock:
> >  	mutex_unlock(&vde->lock);
> >  
> >  release_dpb_frames:
> > @@ -1069,8 +1071,8 @@ static int tegra_vde_probe(struct platform_device *pdev)
> >  	 * power-cycle it in order to put hardware into a predictable lower
> >  	 * power state.
> >  	 */
> > -	pm_runtime_get_sync(dev);
> > -	pm_runtime_put(dev);
> > +	if (pm_runtime_resume_and_get(dev) >= 0)
> > +		pm_runtime_put(dev);
> >  
> >  	return 0;
> >  
> > @@ -1088,8 +1090,9 @@ static int tegra_vde_remove(struct platform_device *pdev)
> >  {
> >  	struct tegra_vde *vde = platform_get_drvdata(pdev);
> >  	struct device *dev = &pdev->dev;
> > +	int ret;
> >  
> > -	pm_runtime_get_sync(dev);
> > +	ret = pm_runtime_resume_and_get(dev);
> >  	pm_runtime_dont_use_autosuspend(dev);
> >  	pm_runtime_disable(dev);
> >  
> > @@ -1097,7 +1100,8 @@ static int tegra_vde_remove(struct platform_device *pdev)
> >  	 * Balance RPM state, the VDE power domain is left ON and hardware
> >  	 * is clock-gated. It's safe to reboot machine now.
> >  	 */
> > -	pm_runtime_put_noidle(dev);
> > +	if (ret >= 0)
> > +		pm_runtime_put_noidle(dev);
> >  	clk_disable_unprepare(vde->clk);
> >  
> >  	misc_deregister(&vde->miscdev);
> >   
> 
> Hello Mauro,
> 
> Thank you very much for the patch. It looks to me that the original
> variant was a bit simpler, this patch adds more code lines without
> changing the previous behaviour. Or am I missing something?

While on several places the newer code is simpler, the end goal here is
to replace all occurrences of pm_runtime_get_sync() from the media 
subsystem, due to the number of problems we're having with this:

1. despite its name, this is actually a PM runtime resume call,
   but some developers didn't seem to realize that, as I got this
   pattern on some drivers:

        pm_runtime_get_sync(&client->dev);
        pm_runtime_disable(&client->dev);
        pm_runtime_set_suspended(&client->dev);
        pm_runtime_put_noidle(&client->dev);

   It makes no sense to resume PM just to suspend it again ;-)

   The name of the new variant is a lot clearer:
	pm_runtime_resume_and_get()

2. Usual *_get() methods only increment their use count on success,
   but pm_runtime_get_sync() increments it unconditionally. Due to
   that, several drivers were mistakenly not calling
   pm_runtime_put_noidle() when it fails;

3. Consistency: we did similar changes subsystem wide with
   for instance strlcpy() and strcpy() that got replaced by
   strscpy(). Having all drivers using the same known-to-be-safe
   methods is a good thing;

4. Prevent newer drivers to copy-and-paste a code that it would
   be easier to break if they don't truly understand what's behind
   the scenes.

Thanks,
Mauro
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Re: [PATCH 17/78] staging: media: vde: use pm_runtime_resume_and_get()

[Johan Hovold]

On Tue, Apr 27, 2021 at 11:22:50AM +0200, Mauro Carvalho Chehab wrote:
> Hi Dmitry,
> 
> Em Sat, 24 Apr 2021 10:35:22 +0300
> Dmitry Osipenko <digetx@gmail.com> escreveu:
> 
> > 24.04.2021 09:44, Mauro Carvalho Chehab пишет:
> > > Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> > > added pm_runtime_resume_and_get() in order to automatically handle
> > > dev->power.usage_count decrement on errors.
> > > 
> > > Use the new API, in order to cleanup the error check logic.
> > > 
> > > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
> > > ---
> > >  drivers/staging/media/tegra-vde/vde.c | 16 ++++++++++------
> > >  1 file changed, 10 insertions(+), 6 deletions(-)
> > > 
> > > diff --git a/drivers/staging/media/tegra-vde/vde.c b/drivers/staging/media/tegra-vde/vde.c
> > > index 28845b5bafaf..8936f140a246 100644
> > > --- a/drivers/staging/media/tegra-vde/vde.c
> > > +++ b/drivers/staging/media/tegra-vde/vde.c
> > > @@ -775,9 +775,9 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
> > >  	if (ret)
> > >  		goto release_dpb_frames;
> > >  
> > > -	ret = pm_runtime_get_sync(dev);
> > > +	ret = pm_runtime_resume_and_get(dev);
> > >  	if (ret < 0)
> > > -		goto put_runtime_pm;
> > > +		goto unlock;
> > >  
> > >  	/*
> > >  	 * We rely on the VDE registers reset value, otherwise VDE
> > > @@ -843,6 +843,8 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
> > >  put_runtime_pm:
> > >  	pm_runtime_mark_last_busy(dev);
> > >  	pm_runtime_put_autosuspend(dev);
> > > +
> > > +unlock:
> > >  	mutex_unlock(&vde->lock);
> > >  
> > >  release_dpb_frames:
> > > @@ -1069,8 +1071,8 @@ static int tegra_vde_probe(struct platform_device *pdev)
> > >  	 * power-cycle it in order to put hardware into a predictable lower
> > >  	 * power state.
> > >  	 */
> > > -	pm_runtime_get_sync(dev);
> > > -	pm_runtime_put(dev);
> > > +	if (pm_runtime_resume_and_get(dev) >= 0)
> > > +		pm_runtime_put(dev);
> > >  
> > >  	return 0;
> > >  
> > > @@ -1088,8 +1090,9 @@ static int tegra_vde_remove(struct platform_device *pdev)
> > >  {
> > >  	struct tegra_vde *vde = platform_get_drvdata(pdev);
> > >  	struct device *dev = &pdev->dev;
> > > +	int ret;
> > >  
> > > -	pm_runtime_get_sync(dev);
> > > +	ret = pm_runtime_resume_and_get(dev);
> > >  	pm_runtime_dont_use_autosuspend(dev);
> > >  	pm_runtime_disable(dev);
> > >  
> > > @@ -1097,7 +1100,8 @@ static int tegra_vde_remove(struct platform_device *pdev)
> > >  	 * Balance RPM state, the VDE power domain is left ON and hardware
> > >  	 * is clock-gated. It's safe to reboot machine now.
> > >  	 */
> > > -	pm_runtime_put_noidle(dev);
> > > +	if (ret >= 0)
> > > +		pm_runtime_put_noidle(dev);
> > >  	clk_disable_unprepare(vde->clk);
> > >  
> > >  	misc_deregister(&vde->miscdev);
> > >   
> > 
> > Hello Mauro,
> > 
> > Thank you very much for the patch. It looks to me that the original
> > variant was a bit simpler, this patch adds more code lines without
> > changing the previous behaviour. Or am I missing something?

I agree, the above does not look like an improvement at all.

> While on several places the newer code is simpler, the end goal here is
> to replace all occurrences of pm_runtime_get_sync() from the media 
> subsystem, due to the number of problems we're having with this:
> 
> 1. despite its name, this is actually a PM runtime resume call,
>    but some developers didn't seem to realize that, as I got this
>    pattern on some drivers:
> 
>         pm_runtime_get_sync(&client->dev);
>         pm_runtime_disable(&client->dev);
>         pm_runtime_set_suspended(&client->dev);
>         pm_runtime_put_noidle(&client->dev);
> 
>    It makes no sense to resume PM just to suspend it again ;-)

It very well may. You're resuming the device and leaving it a defined
power state before balancing the PM count, cleaning up and unbinding the
driver.

>    The name of the new variant is a lot clearer:
> 	pm_runtime_resume_and_get()

For people not used to the API perhaps.

> 2. Usual *_get() methods only increment their use count on success,
>    but pm_runtime_get_sync() increments it unconditionally. Due to
>    that, several drivers were mistakenly not calling
>    pm_runtime_put_noidle() when it fails;

As I mentioned elsewhere, all pm_runtime_get calls increment the usage
count so the API is consistent.
 
> 3. Consistency: we did similar changes subsystem wide with
>    for instance strlcpy() and strcpy() that got replaced by
>    strscpy(). Having all drivers using the same known-to-be-safe
>    methods is a good thing;

There's no know-to-be safe API. People will find ways to get this wrong
too.

And the old interface isn't going away from the kernel even if you
manage to not use it in media.

> 4. Prevent newer drivers to copy-and-paste a code that it would
>    be easier to break if they don't truly understand what's behind
>    the scenes.

Johan
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Re: [PATCH 00/78] media: use pm_runtime_resume_and_get() instead of pm_runtime_get_sync()

[Dan Carpenter]

There was a Smatch check for these bugs.  This was a good source of
recurring Reported-by tags for me.  ;)  Thanks for doing this.

regards,
dan carpenter

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