[PATCH v8 15/19] media: uvcvideo: Set error_idx during ctrl_commit errors

[Ricardo Ribalda]

If we have an error setting a control, return the affected control in
the error_idx field.

Signed-off-by: Ricardo Ribalda <riba...@chromium.org>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 42 ++++++++++++++++++++++++++------
 drivers/media/usb/uvc/uvc_v4l2.c |  2 +-
 drivers/media/usb/uvc/uvcvideo.h | 10 +++-----
 3 files changed, 40 insertions(+), 14 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 24fd5afc4e4f..bcebf9d1a46f 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1586,7 +1586,7 @@ int uvc_ctrl_begin(struct uvc_video_chain *chain)
 }
 
 static int uvc_ctrl_commit_entity(struct uvc_device *dev,
-       struct uvc_entity *entity, int rollback)
+       struct uvc_entity *entity, int rollback, struct uvc_control **err_ctrl)
 {
        struct uvc_control *ctrl;
        unsigned int i;
@@ -1628,31 +1628,59 @@ static int uvc_ctrl_commit_entity(struct uvc_device 
*dev,
 
                ctrl->dirty = 0;
 
-               if (ret < 0)
+               if (ret < 0) {
+                       if (err_ctrl)
+                               *err_ctrl = ctrl;
                        return ret;
+               }
        }
 
        return 0;
 }
 
+static int uvc_ctrl_find_ctrlidx(struct uvc_entity *entity,
+                                struct v4l2_ext_controls *ctrls,
+                                struct uvc_control *uvc_control)
+{
+       struct uvc_control_mapping *mapping;
+       struct uvc_control *ctrl_found;
+       unsigned int i;
+
+       if (!entity)
+               return ctrls->count;
+
+       for (i = 0; i < ctrls->count; i++) {
+               __uvc_find_control(entity, ctrls->controls[i].id, &mapping,
+                                  &ctrl_found, 0);
+               if (uvc_control == ctrl_found)
+                       return i;
+       }
+
+       return ctrls->count;
+}
+
 int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
-                     const struct v4l2_ext_control *xctrls,
-                     unsigned int xctrls_count)
+                     struct v4l2_ext_controls *ctrls)
 {
        struct uvc_video_chain *chain = handle->chain;
+       struct uvc_control *err_ctrl;
        struct uvc_entity *entity;
        int ret = 0;
 
        /* Find the control. */
        list_for_each_entry(entity, &chain->entities, chain) {
-               ret = uvc_ctrl_commit_entity(chain->dev, entity, rollback);
+               ret = uvc_ctrl_commit_entity(chain->dev, entity, rollback,
+                                            &err_ctrl);
                if (ret < 0)
                        goto done;
        }
 
        if (!rollback)
-               uvc_ctrl_send_events(handle, xctrls, xctrls_count);
+               uvc_ctrl_send_events(handle, ctrls->controls, ctrls->count);
 done:
+       if (ret < 0 && ctrls)
+               ctrls->error_idx = uvc_ctrl_find_ctrlidx(entity, ctrls,
+                                                        err_ctrl);
        mutex_unlock(&chain->ctrl_mutex);
        return ret;
 }
@@ -2110,7 +2138,7 @@ int uvc_ctrl_restore_values(struct uvc_device *dev)
                        ctrl->dirty = 1;
                }
 
-               ret = uvc_ctrl_commit_entity(dev, entity, 0);
+               ret = uvc_ctrl_commit_entity(dev, entity, 0, NULL);
                if (ret < 0)
                        return ret;
        }
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index a3ee1dc003fc..8d8b12a4db34 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -1088,7 +1088,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh 
*handle,
        ctrls->error_idx = 0;
 
        if (ioctl == VIDIOC_S_EXT_CTRLS)
-               return uvc_ctrl_commit(handle, ctrls->controls, ctrls->count);
+               return uvc_ctrl_commit(handle, ctrls);
        else
                return uvc_ctrl_rollback(handle);
 }
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 9471c342a310..0313b30f0cea 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -887,17 +887,15 @@ void uvc_ctrl_status_event(struct uvc_video_chain *chain,
 
 int uvc_ctrl_begin(struct uvc_video_chain *chain);
 int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
-                     const struct v4l2_ext_control *xctrls,
-                     unsigned int xctrls_count);
+                     struct v4l2_ext_controls *ctrls);
 static inline int uvc_ctrl_commit(struct uvc_fh *handle,
-                                 const struct v4l2_ext_control *xctrls,
-                                 unsigned int xctrls_count)
+                                 struct v4l2_ext_controls *ctrls)
 {
-       return __uvc_ctrl_commit(handle, 0, xctrls, xctrls_count);
+       return __uvc_ctrl_commit(handle, 0, ctrls);
 }
 static inline int uvc_ctrl_rollback(struct uvc_fh *handle)
 {
-       return __uvc_ctrl_commit(handle, 1, NULL, 0);
+       return __uvc_ctrl_commit(handle, 1, NULL);
 }
 
 int uvc_ctrl_get(struct uvc_video_chain *chain, struct v4l2_ext_control 
*xctrl);
-- 
2.31.0.rc2.261.g7f71774620-goog