media: atmel: properly get pm_runtime

There are several issues in the way the atmel driver handles
pm_runtime_get_sync():

- it doesn't check return codes;
- it doesn't properly decrement the usage_count on all places;
- it starts streaming even if pm_runtime_get_sync() fails.
- while it tries to get pm_runtime at the clock enable logic,
  it doesn't check if the operation was suceeded.

Replace all occurrences of it to use the new kAPI:
pm_runtime_resume_and_get(), which ensures that, if the
return code is not negative, the usage_count was incremented.

With that, add additional checks when this is called, in order
to ensure that errors will be properly addressed.

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

diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
index fe3ec8d..ce8e135 100644 (file)
--- a/drivers/media/platform/atmel/atmel-isc-base.c
+++ b/drivers/media/platform/atmel/atmel-isc-base.c
@@ -294,9 +294,13 @@ static int isc_wait_clk_stable(struct clk_hw *hw)
 static int isc_clk_prepare(struct clk_hw *hw)
 {
        struct isc_clk *isc_clk = to_isc_clk(hw);
+       int ret;
 
-       if (isc_clk->id == ISC_ISPCK)
-               pm_runtime_get_sync(isc_clk->dev);
+       if (isc_clk->id == ISC_ISPCK) {
+               ret = pm_runtime_resume_and_get(isc_clk->dev);
+               if (ret < 0)
+                       return ret;
+       }
 
        return isc_wait_clk_stable(hw);
 }
@@ -353,9 +357,13 @@ static int isc_clk_is_enabled(struct clk_hw *hw)
 {
        struct isc_clk *isc_clk = to_isc_clk(hw);
        u32 status;
+       int ret;
 
-       if (isc_clk->id == ISC_ISPCK)
-               pm_runtime_get_sync(isc_clk->dev);
+       if (isc_clk->id == ISC_ISPCK) {
+               ret = pm_runtime_resume_and_get(isc_clk->dev);
+               if (ret < 0)
+                       return 0;
+       }
 
        regmap_read(isc_clk->regmap, ISC_CLKSR, &status);
 
@@ -807,7 +815,12 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
                goto err_start_stream;
        }
 
-       pm_runtime_get_sync(isc->dev);
+       ret = pm_runtime_resume_and_get(isc->dev);
+       if (ret < 0) {
+               v4l2_err(&isc->v4l2_dev, "RPM resume failed in subdev %d\n",
+                        ret);
+               goto err_pm_get;
+       }
 
        ret = isc_configure(isc);
        if (unlikely(ret))
@@ -838,7 +851,7 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
 
 err_configure:
        pm_runtime_put_sync(isc->dev);
-
+err_pm_get:
        v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 0);
 
 err_start_stream:
@@ -1809,6 +1822,7 @@ static void isc_awb_work(struct work_struct *w)
        u32 baysel;
        unsigned long flags;
        u32 min, max;
+       int ret;
 
        /* streaming is not active anymore */
        if (isc->stop)
@@ -1831,7 +1845,9 @@ static void isc_awb_work(struct work_struct *w)
        ctrls->hist_id = hist_id;
        baysel = isc->config.sd_format->cfa_baycfg << ISC_HIS_CFG_BAYSEL_SHIFT;
 
-       pm_runtime_get_sync(isc->dev);
+       ret = pm_runtime_resume_and_get(isc->dev);
+       if (ret < 0)
+               return;
 
        /*
         * only update if we have all the required histograms and controls

diff --git a/drivers/media/platform/atmel/atmel-isi.c b/drivers/media/platform/atmel/atmel-isi.c
index e392b3e..5b1dd35 100644 (file)
--- a/drivers/media/platform/atmel/atmel-isi.c
+++ b/drivers/media/platform/atmel/atmel-isi.c
@@ -422,7 +422,9 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
        struct frame_buffer *buf, *node;
        int ret;
 
-       pm_runtime_get_sync(isi->dev);
+       ret = pm_runtime_resume_and_get(isi->dev);
+       if (ret < 0)
+               return ret;
 
        /* Enable stream on the sub device */
        ret = v4l2_subdev_call(isi->entity.subdev, video, s_stream, 1);
@@ -782,9 +784,10 @@ static int isi_enum_frameintervals(struct file *file, void *fh,
        return 0;
 }
 
-static void isi_camera_set_bus_param(struct atmel_isi *isi)
+static int isi_camera_set_bus_param(struct atmel_isi *isi)
 {
        u32 cfg1 = 0;
+       int ret;
 
        /* set bus param for ISI */
        if (isi->pdata.hsync_act_low)
@@ -801,12 +804,16 @@ static void isi_camera_set_bus_param(struct atmel_isi *isi)
        cfg1 |= ISI_CFG1_THMASK_BEATS_16;
 
        /* Enable PM and peripheral clock before operate isi registers */
-       pm_runtime_get_sync(isi->dev);
+       ret = pm_runtime_resume_and_get(isi->dev);
+       if (ret < 0)
+               return ret;
 
        isi_writel(isi, ISI_CTRL, ISI_CTRL_DIS);
        isi_writel(isi, ISI_CFG1, cfg1);
 
        pm_runtime_put(isi->dev);
+
+       return 0;
 }
 
 /* -----------------------------------------------------------------------*/
@@ -1085,7 +1092,11 @@ static int isi_graph_notify_complete(struct v4l2_async_notifier *notifier)
                dev_err(isi->dev, "No supported mediabus format found\n");
                return ret;
        }
-       isi_camera_set_bus_param(isi);
+       ret = isi_camera_set_bus_param(isi);
+       if (ret) {
+               dev_err(isi->dev, "Can't wake up device\n");
+               return ret;
+       }
 
        ret = isi_set_default_fmt(isi);
        if (ret) {