From: Ricardo Ribalda Date: Mon, 24 Feb 2025 10:34:55 +0000 (+0000) Subject: media: uvcvideo: Rollback non processed entities on error X-Git-Tag: v5.10.240~79 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f18d72695d67b4c3b042c03317f9263efedc1665;p=thirdparty%2Fkernel%2Fstable.git media: uvcvideo: Rollback non processed entities on error commit a70705d3c020d0d5c3ab6a5cc93e011ac35e7d48 upstream. If we fail to commit an entity, we need to restore the UVC_CTRL_DATA_BACKUP for the other uncommitted entities. Otherwise the control cache and the device would be out of sync. Cc: stable@kernel.org Fixes: b4012002f3a3 ("[media] uvcvideo: Add support for control events") Reported-by: Hans de Goede Closes: https://lore.kernel.org/linux-media/fe845e04-9fde-46ee-9763-a6f00867929a@redhat.com/ Signed-off-by: Ricardo Ribalda Message-ID: <20250224-uvc-data-backup-v2-3-de993ed9823b@chromium.org> Signed-off-by: Hans de Goede Signed-off-by: Hans Verkuil Signed-off-by: Ricardo Ribalda Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index a4b082df3b063..4f67ba3a7c028 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -1577,7 +1577,7 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev, unsigned int processed_ctrls = 0; struct uvc_control *ctrl; unsigned int i; - int ret; + int ret = 0; if (entity == NULL) return 0; @@ -1605,8 +1605,6 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev, dev->intfnum, ctrl->info.selector, uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT), ctrl->info.size); - else - ret = 0; if (!ret) processed_ctrls++; @@ -1618,14 +1616,22 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev, ctrl->dirty = 0; - if (ret < 0) - return ret; - - if (!rollback && handle && + if (!rollback && handle && !ret && ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS) uvc_ctrl_set_handle(handle, ctrl, handle); + + if (ret < 0 && !rollback) { + /* + * If we fail to set a control, we need to rollback + * the next ones. + */ + rollback = 1; + } } + if (ret) + return ret; + return processed_ctrls; } @@ -1635,23 +1641,31 @@ int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback, { struct uvc_video_chain *chain = handle->chain; struct uvc_entity *entity; - int ret = 0; + int ret_out = 0; + int ret; /* Find the control. */ list_for_each_entry(entity, &chain->entities, chain) { ret = uvc_ctrl_commit_entity(chain->dev, handle, entity, rollback); - if (ret < 0) - goto done; - else if (ret > 0 && !rollback) + if (ret < 0) { + /* + * When we fail to commit an entity, we need to + * restore the UVC_CTRL_DATA_BACKUP for all the + * controls in the other entities, otherwise our cache + * and the hardware will be out of sync. + */ + rollback = 1; + + ret_out = ret; + } else if (ret > 0 && !rollback) { uvc_ctrl_send_events(handle, entity, xctrls, xctrls_count); + } } - ret = 0; -done: mutex_unlock(&chain->ctrl_mutex); - return ret; + return ret_out; } int uvc_ctrl_get(struct uvc_video_chain *chain,