[media] pwc: Read new preset values when changing awb control to a preset

So that events get generated for the new red + blue bal values when switching
to a preset. This allows apps to solely rely on events instead of needing
to do a query + g_ctrl on all controls when a control with the update flag
set is gets set or gets an event.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 23 insertions, 8 deletions

diff --git a/drivers/media/video/pwc/pwc-v4l.c b/drivers/media/video/pwc/pwc-v4l.c
index 97e8d629582..566b09c7980 100644
--- a/drivers/media/video/pwc/pwc-v4l.c
+++ b/drivers/media/video/pwc/pwc-v4l.c
@@ -575,18 +575,14 @@ static int pwc_s_input(struct file *file, void *fh, unsigned int i)
         return i ? -EINVAL : 0;
 }
 
-static int pwc_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
+static int pwc_g_volatile_ctrl_unlocked(struct v4l2_ctrl *ctrl)
 {
         struct pwc_device *pdev =
                 container_of(ctrl->handler, struct pwc_device, ctrl_handler);
         int ret = 0;
 
-        mutex_lock(&pdev->udevlock);
-
-        if (!pdev->udev) {
-                ret = -ENODEV;
-                goto leave;
-        }
+        if (!pdev->udev)
+                return -ENODEV;
 
         switch (ctrl->id) {
         case V4L2_CID_AUTO_WHITE_BALANCE:
@@ -651,7 +647,17 @@ static int pwc_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
         if (ret)
                 PWC_ERROR("g_ctrl %s error %d\n", ctrl->name, ret);
 
-leave:
+        return ret;
+}
+
+static int pwc_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
+{
+        struct pwc_device *pdev =
+                container_of(ctrl->handler, struct pwc_device, ctrl_handler);
+        int ret;
+
+        mutex_lock(&pdev->udevlock);
+        ret = pwc_g_volatile_ctrl_unlocked(ctrl);
         mutex_unlock(&pdev->udevlock);
         return ret;
 }
@@ -669,6 +675,15 @@ static int pwc_set_awb(struct pwc_device *pdev)
 
                 if (pdev->auto_white_balance->val != awb_manual)
                         pdev->color_bal_valid = false; /* Force cache update */
+
+                /*
+                 * If this is a preset, update our red / blue balance values
+                 * so that events get generated for the new preset values
+                 */
+                if (pdev->auto_white_balance->val == awb_indoor ||
+                    pdev->auto_white_balance->val == awb_outdoor ||
+                    pdev->auto_white_balance->val == awb_fl)
+                        pwc_g_volatile_ctrl_unlocked(pdev->auto_white_balance);
         }
         if (pdev->auto_white_balance->val != awb_manual)
                 return 0;