From patchwork Thu Mar 8 17:20:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guennadi Liakhovetski X-Patchwork-Id: 10268555 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 84003602C8 for ; Thu, 8 Mar 2018 17:21:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 729BC299FB for ; Thu, 8 Mar 2018 17:21:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6D464299AC; Thu, 8 Mar 2018 17:21:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,FREEMAIL_FROM, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C369829B0C for ; Thu, 8 Mar 2018 17:21:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934073AbeCHRVL (ORCPT ); Thu, 8 Mar 2018 12:21:11 -0500 Received: from mout.gmx.net ([212.227.15.19]:52663 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934104AbeCHRVK (ORCPT ); Thu, 8 Mar 2018 12:21:10 -0500 Received: from axis700.grange ([84.44.204.122]) by mail.gmx.com (mrgmx002 [212.227.17.190]) with ESMTPSA (Nemesis) id 0MhAAr-1fFcns0L8D-00MI7N; Thu, 08 Mar 2018 18:20:53 +0100 Received: by axis700.grange (Postfix, from userid 1000) id 5CE7060EFB; Thu, 8 Mar 2018 18:20:51 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by axis700.grange (Postfix) with ESMTP id 4A9B960AE4; Thu, 8 Mar 2018 18:20:51 +0100 (CET) Date: Thu, 8 Mar 2018 18:20:50 +0100 (CET) From: Guennadi Liakhovetski X-X-Sender: lyakh@axis700.grange To: Linux Media Mailing List cc: Laurent Pinchart , Mauro Carvalho Chehab , Hans Verkuil Subject: [PATCH RESEND 1/2 v6] uvcvideo: send a control event when a Control Change interrupt arrives Message-ID: User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 X-Provags-ID: V03:K0:gxpRWodV929vMvmkWjzuSwgwfIBDYIdjleJqIJsOuvlVD7VOU0j 3lH4e+hZLyD/UH82qBCaqP833nJVa/xTxfIhpgOnt3uKqOw9lbi8z4rkwPFTmmO2QtHsfwQ H3LYxv6uj3lDqlqLQ23wBg7jpXEAzuMXZcn/TT7CkfUUeFn8WKBFLTodOk3+OICSDsHh42c R3CwUk9wXOi9xzAMTiQSg== X-UI-Out-Filterresults: notjunk:1; V01:K0:jyZ1Dj7XiGE=:1lFQDVJjFr3WL7xjooPnEx +Xc7drtDZkLkEBqi4RU0bELKcjNpCkxTEZiz2fpeyEwIH/7AcZc6vfXZkJocodF8sphxE+ePD VQR+TZ2/ceC1PRcRvV4+VZqp/M7dNeQnUMjMNR3N/g1gGR3O3thpoKwre6NNz1k4RCitQ9dMI 71xRyOJ78SopViJU132mrzUGWPy/POxiXdTYmHmiljy+CmofdZlO3tLzjpvY0Djb8KGs8sfSN ZDq3RUQzph/QFcg0tzQS5YIzP0vM2HM1pFRQQCiiqBRAZ0Hm31qTXzt0uBPjzbm43WWp7hHsj JXm89TIPLy3Q6xZ/Hz9M5Fg6l4x6Cj4gvf7oZHPPeL7Jmu5bRTJ5P4y8Uoar0qU/e1xYXkBqq EnRcvpVGkTfsoFuvpZfblwYzcze4Ezk9ahANFHxTlmtyrpSskrICZznWlO1iRmrjwjSnF8vTI DPfaJ/K6KjDSKskIiCl2SBjthJ311hiAJsQeanYhCh/MvW8WMrgDf6Zd94qie7Eb9Jnp9mVVY tNCLw//hdBX2V2IACnEuNKHwKc6ew6bjjwwj/tfrU8hyiJmdhugRzUKpTqgRneBpepkeggWLs Jb3iGb2oAHjfv3cIAvPf2U0KxhH92K9qum5EzDBkAnWYCa6UCfniTRMWScbEiAgGkhCJjNvx5 r3KeRb2ayCqJWXVTqQzfelECzv0cZfvbvARvnwPyZA86qAZqEcGhJovlH3LShcLgZF81zMZFm 0blUoPztSCqqStK2u2l/r73EerHy/GVpABYf3GeFIBegQlXf+H690DFFZjghSfHxzOybS/OZt yiImsf4h0vViCG6P/Rm2w1HhH12xztIe8ceyf2JWhPSoJ5xxTA= Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP UVC defines a method of handling asynchronous controls, which sends a USB packet over the interrupt pipe. This patch implements support for such packets by sending a control event to the user. Since this can involve USB traffic and, therefore, scheduling, this has to be done in a work queue. Signed-off-by: Guennadi Liakhovetski --- drivers/media/usb/uvc/uvc_ctrl.c | 166 +++++++++++++++++++++++++++++++++---- drivers/media/usb/uvc/uvc_status.c | 111 ++++++++++++++++++++++--- drivers/media/usb/uvc/uvc_v4l2.c | 4 +- drivers/media/usb/uvc/uvcvideo.h | 15 +++- include/uapi/linux/uvcvideo.h | 2 + 5 files changed, 269 insertions(+), 29 deletions(-) diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index 20397ab..2a592c2 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -1222,30 +1223,134 @@ static void uvc_ctrl_send_event(struct uvc_fh *handle, { struct v4l2_subscribed_event *sev; struct v4l2_event ev; + bool autoupdate; if (list_empty(&mapping->ev_subs)) return; + if (!handle) { + autoupdate = true; + sev = list_first_entry(&mapping->ev_subs, + struct v4l2_subscribed_event, node); + handle = container_of(sev->fh, struct uvc_fh, vfh); + } else { + autoupdate = false; + } + uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, value, changes); list_for_each_entry(sev, &mapping->ev_subs, node) { if (sev->fh && (sev->fh != &handle->vfh || (sev->flags & V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK) || - (changes & V4L2_EVENT_CTRL_CH_FLAGS))) + (changes & V4L2_EVENT_CTRL_CH_FLAGS) || autoupdate)) v4l2_event_queue_fh(sev->fh, &ev); } } -static void uvc_ctrl_send_slave_event(struct uvc_fh *handle, - struct uvc_control *master, u32 slave_id, - const struct v4l2_ext_control *xctrls, unsigned int xctrls_count) +static void __uvc_ctrl_send_slave_event(struct uvc_fh *handle, + struct uvc_control *master, u32 slave_id) { struct uvc_control_mapping *mapping = NULL; struct uvc_control *ctrl = NULL; u32 changes = V4L2_EVENT_CTRL_CH_FLAGS; - unsigned int i; s32 val = 0; + __uvc_find_control(master->entity, slave_id, &mapping, &ctrl, 0); + if (ctrl == NULL) + return; + + if (__uvc_ctrl_get(handle->chain, ctrl, mapping, &val) == 0) + changes |= V4L2_EVENT_CTRL_CH_VALUE; + + uvc_ctrl_send_event(handle, ctrl, mapping, val, changes); +} + +static void uvc_ctrl_status_event_work(struct work_struct *work) +{ + struct uvc_device *dev = container_of(work, struct uvc_device, + async_ctrl.work); + struct uvc_video_chain *chain; + struct uvc_ctrl_work *w = &dev->async_ctrl; + struct uvc_control_mapping *mapping; + struct uvc_control *ctrl; + struct uvc_fh *handle; + __u8 *data; + unsigned int i; + + spin_lock_irq(&w->lock); + data = w->data; + w->data = NULL; + chain = w->chain; + ctrl = w->ctrl; + handle = ctrl->handle; + ctrl->handle = NULL; + spin_unlock_irq(&w->lock); + + if (mutex_lock_interruptible(&chain->ctrl_mutex)) + goto free; + + list_for_each_entry(mapping, &ctrl->info.mappings, list) { + s32 value = mapping->get(mapping, UVC_GET_CUR, data); + + for (i = 0; i < ARRAY_SIZE(mapping->slave_ids); ++i) { + if (!mapping->slave_ids[i]) + break; + + __uvc_ctrl_send_slave_event(handle, ctrl, + mapping->slave_ids[i]); + } + + if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) { + struct uvc_menu_info *menu = mapping->menu_info; + unsigned int i; + + for (i = 0; i < mapping->menu_count; ++i, ++menu) + if (menu->value == value) { + value = i; + break; + } + } + + uvc_ctrl_send_event(handle, ctrl, mapping, value, + V4L2_EVENT_CTRL_CH_VALUE); + } + + mutex_unlock(&chain->ctrl_mutex); + +free: + kfree(data); +} + +void uvc_ctrl_status_event(struct uvc_video_chain *chain, + struct uvc_control *ctrl, __u8 *data, size_t len) +{ + struct uvc_device *dev = chain->dev; + struct uvc_ctrl_work *w = &dev->async_ctrl; + + if (list_empty(&ctrl->info.mappings)) + return; + + spin_lock(&w->lock); + if (w->data) + /* A previous event work hasn't run yet, we lose 1 event */ + kfree(w->data); + + w->data = kmalloc(len, GFP_ATOMIC); + if (w->data) { + memcpy(w->data, data, len); + w->chain = chain; + w->ctrl = ctrl; + schedule_work(&w->work); + } + spin_unlock(&w->lock); +} + +static void uvc_ctrl_send_slave_event(struct uvc_fh *handle, + struct uvc_control *master, u32 slave_id, + const struct v4l2_ext_control *xctrls, unsigned int xctrls_count) +{ + unsigned int i; + /* * We can skip sending an event for the slave if the slave * is being modified in the same transaction. @@ -1255,14 +1360,7 @@ static void uvc_ctrl_send_slave_event(struct uvc_fh *handle, return; } - __uvc_find_control(master->entity, slave_id, &mapping, &ctrl, 0); - if (ctrl == NULL) - return; - - if (__uvc_ctrl_get(handle->chain, ctrl, mapping, &val) == 0) - changes |= V4L2_EVENT_CTRL_CH_VALUE; - - uvc_ctrl_send_event(handle, ctrl, mapping, val, changes); + __uvc_ctrl_send_slave_event(handle, master, slave_id); } static void uvc_ctrl_send_events(struct uvc_fh *handle, @@ -1277,6 +1375,10 @@ static void uvc_ctrl_send_events(struct uvc_fh *handle, for (i = 0; i < xctrls_count; ++i) { ctrl = uvc_find_control(handle->chain, xctrls[i].id, &mapping); + if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS) + /* Notification will be sent from an Interrupt event */ + continue; + for (j = 0; j < ARRAY_SIZE(mapping->slave_ids); ++j) { if (!mapping->slave_ids[j]) break; @@ -1472,9 +1574,10 @@ int uvc_ctrl_get(struct uvc_video_chain *chain, return __uvc_ctrl_get(chain, ctrl, mapping, &xctrl->value); } -int uvc_ctrl_set(struct uvc_video_chain *chain, +int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl) { + struct uvc_video_chain *chain = handle->chain; struct uvc_control *ctrl; struct uvc_control_mapping *mapping; s32 value; @@ -1488,6 +1591,25 @@ int uvc_ctrl_set(struct uvc_video_chain *chain, return -EINVAL; if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR)) return -EACCES; + if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS) { + if (ctrl->handle) + /* + * We have already sent this control to the camera + * recently and are currently waiting for a completion + * notification. The camera might already have completed + * its processing and is ready to accept a new control + * or it's still busy processing. If we send a new + * instance of this control now, in the former case the + * camera will process this one too and we'll get + * completions for both, but we will only deliver an + * event for one of them back to the user. In the latter + * case the camera will reply with a STALL. It's easier + * and more reliable to return an error now and let the + * user retry. + */ + return -EBUSY; + ctrl->handle = handle; + } /* Clamp out of range values. */ switch (mapping->v4l2_type) { @@ -1676,7 +1798,9 @@ static int uvc_ctrl_fill_xu_info(struct uvc_device *dev, | (data[0] & UVC_CONTROL_CAP_SET ? UVC_CTRL_FLAG_SET_CUR : 0) | (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ? - UVC_CTRL_FLAG_AUTO_UPDATE : 0); + UVC_CTRL_FLAG_AUTO_UPDATE : 0) + | (data[0] & UVC_CONTROL_CAP_ASYNCHRONOUS ? + UVC_CTRL_FLAG_ASYNCHRONOUS : 0); uvc_ctrl_fixup_xu_info(dev, ctrl, info); @@ -2131,6 +2255,13 @@ static void uvc_ctrl_init_ctrl(struct uvc_device *dev, struct uvc_control *ctrl) if (!ctrl->initialized) return; + /* Temporarily abuse DATA_CURRENT buffer to avoid 1 byte allocation */ + if (!uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, + dev->intfnum, info->selector, + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT), 1) && + uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT)[0] & 0x10) + ctrl->info.flags |= UVC_CTRL_FLAG_ASYNCHRONOUS; + for (; mapping < mend; ++mapping) { if (uvc_entity_match_guid(ctrl->entity, mapping->entity) && ctrl->info.selector == mapping->selector) @@ -2146,6 +2277,9 @@ int uvc_ctrl_init_device(struct uvc_device *dev) struct uvc_entity *entity; unsigned int i; + spin_lock_init(&dev->async_ctrl.lock); + INIT_WORK(&dev->async_ctrl.work, uvc_ctrl_status_event_work); + /* Walk the entities list and instantiate controls */ list_for_each_entry(entity, &dev->entities, list) { struct uvc_control *ctrl; @@ -2214,6 +2348,8 @@ void uvc_ctrl_cleanup_device(struct uvc_device *dev) struct uvc_entity *entity; unsigned int i; + cancel_work_sync(&dev->async_ctrl.work); + /* Free controls and control mappings for all entities. */ list_for_each_entry(entity, &dev->entities, list) { for (i = 0; i < entity->ncontrols; ++i) { diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c index 1ef20e7..440a7be 100644 --- a/drivers/media/usb/uvc/uvc_status.c +++ b/drivers/media/usb/uvc/uvc_status.c @@ -78,7 +78,24 @@ static void uvc_input_report_key(struct uvc_device *dev, unsigned int code, /* -------------------------------------------------------------------------- * Status interrupt endpoint */ -static void uvc_event_streaming(struct uvc_device *dev, __u8 *data, int len) +struct uvc_streaming_status { + __u8 bStatusType; + __u8 bOriginator; + __u8 bEvent; + __u8 bValue[]; +} __packed; + +struct uvc_control_status { + __u8 bStatusType; + __u8 bOriginator; + __u8 bEvent; + __u8 bSelector; + __u8 bAttribute; + __u8 bValue[]; +} __packed; + +static void uvc_event_streaming(struct uvc_device *dev, + struct uvc_streaming_status *status, int len) { if (len < 3) { uvc_trace(UVC_TRACE_STATUS, "Invalid streaming status event " @@ -86,31 +103,101 @@ static void uvc_event_streaming(struct uvc_device *dev, __u8 *data, int len) return; } - if (data[2] == 0) { + if (status->bEvent == 0) { if (len < 4) return; uvc_trace(UVC_TRACE_STATUS, "Button (intf %u) %s len %d\n", - data[1], data[3] ? "pressed" : "released", len); - uvc_input_report_key(dev, KEY_CAMERA, data[3]); + status->bOriginator, + status->bValue[0] ? "pressed" : "released", len); + uvc_input_report_key(dev, KEY_CAMERA, status->bValue[0]); } else { uvc_trace(UVC_TRACE_STATUS, "Stream %u error event %02x len %d.\n", - data[1], data[2], len); + status->bOriginator, status->bEvent, len); } } -static void uvc_event_control(struct uvc_device *dev, __u8 *data, int len) +#define UVC_CTRL_VALUE_CHANGE 0 +#define UVC_CTRL_INFO_CHANGE 1 +#define UVC_CTRL_FAILURE_CHANGE 2 +#define UVC_CTRL_MIN_CHANGE 3 +#define UVC_CTRL_MAX_CHANGE 4 + +static struct uvc_control *uvc_event_entity_ctrl(struct uvc_entity *entity, + __u8 selector) +{ + struct uvc_control *ctrl; + unsigned int i; + + for (i = 0, ctrl = entity->controls; i < entity->ncontrols; i++, ctrl++) + if (ctrl->info.selector == selector) + return ctrl; + + return NULL; +} + +static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev, + struct uvc_control_status *status, + struct uvc_video_chain **chain) +{ + list_for_each_entry((*chain), &dev->chains, list) { + struct uvc_entity *entity; + struct uvc_control *ctrl; + + list_for_each_entry(entity, &(*chain)->entities, chain) { + if (entity->id == status->bOriginator) { + ctrl = uvc_event_entity_ctrl(entity, + status->bSelector); + /* + * Some buggy cameras send asynchronous Control + * Change events for control, other than the + * ones, that had been changed, even though the + * AutoUpdate flag isn't set for the control. + */ + if (ctrl && (!ctrl->handle || + ctrl->handle->chain == *chain)) + return ctrl; + } + } + } + + return NULL; +} + +static void uvc_event_control(struct uvc_device *dev, + struct uvc_control_status *status, int len) { - char *attrs[3] = { "value", "info", "failure" }; + struct uvc_video_chain *chain; + struct uvc_control *ctrl; + char *attrs[] = { "value", "info", "failure", "min", "max" }; - if (len < 6 || data[2] != 0 || data[4] > 2) { + if (len < 6 || status->bEvent != 0 || + status->bAttribute >= ARRAY_SIZE(attrs)) { uvc_trace(UVC_TRACE_STATUS, "Invalid control status event " "received.\n"); return; } uvc_trace(UVC_TRACE_STATUS, "Control %u/%u %s change len %d.\n", - data[1], data[3], attrs[data[4]], len); + status->bOriginator, status->bSelector, + attrs[status->bAttribute], len); + + /* Find the control. */ + ctrl = uvc_event_find_ctrl(dev, status, &chain); + if (!ctrl) + return; + + switch (status->bAttribute) { + case UVC_CTRL_VALUE_CHANGE: + uvc_ctrl_status_event(chain, ctrl, status->bValue, len - + offsetof(struct uvc_control_status, bValue)); + break; + case UVC_CTRL_INFO_CHANGE: + case UVC_CTRL_FAILURE_CHANGE: + case UVC_CTRL_MIN_CHANGE: + case UVC_CTRL_MAX_CHANGE: + break; + } } static void uvc_status_complete(struct urb *urb) @@ -139,11 +226,13 @@ static void uvc_status_complete(struct urb *urb) if (len > 0) { switch (dev->status[0] & 0x0f) { case UVC_STATUS_TYPE_CONTROL: - uvc_event_control(dev, dev->status, len); + uvc_event_control(dev, + (struct uvc_control_status *)dev->status, len); break; case UVC_STATUS_TYPE_STREAMING: - uvc_event_streaming(dev, dev->status, len); + uvc_event_streaming(dev, + (struct uvc_streaming_status *)dev->status, len); break; default: diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c index 5e03239..40863eb 100644 --- a/drivers/media/usb/uvc/uvc_v4l2.c +++ b/drivers/media/usb/uvc/uvc_v4l2.c @@ -966,7 +966,7 @@ static int uvc_ioctl_s_ctrl(struct file *file, void *fh, if (ret < 0) return ret; - ret = uvc_ctrl_set(chain, &xctrl); + ret = uvc_ctrl_set(handle, &xctrl); if (ret < 0) { uvc_ctrl_rollback(handle); return ret; @@ -1041,7 +1041,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle, return ret; for (i = 0; i < ctrls->count; ++ctrl, ++i) { - ret = uvc_ctrl_set(chain, ctrl); + ret = uvc_ctrl_set(handle, ctrl); if (ret < 0) { uvc_ctrl_rollback(handle); ctrls->error_idx = commit ? ctrls->count : i; diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h index b65e86b..3fa089f 100644 --- a/drivers/media/usb/uvc/uvcvideo.h +++ b/drivers/media/usb/uvc/uvcvideo.h @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -255,6 +256,8 @@ struct uvc_control { initialized:1; __u8 *uvc_data; + + struct uvc_fh *handle; /* Used for asynchronous event delivery */ }; struct uvc_format_desc { @@ -599,6 +602,14 @@ struct uvc_device { __u8 *status; struct input_dev *input; char input_phys[64]; + + struct uvc_ctrl_work { + struct work_struct work; + struct uvc_video_chain *chain; + struct uvc_control *ctrl; + spinlock_t lock; + void *data; + } async_ctrl; }; enum uvc_handle_state { @@ -754,6 +765,8 @@ extern int uvc_ctrl_add_mapping(struct uvc_video_chain *chain, extern int uvc_ctrl_init_device(struct uvc_device *dev); extern void uvc_ctrl_cleanup_device(struct uvc_device *dev); extern int uvc_ctrl_restore_values(struct uvc_device *dev); +extern void uvc_ctrl_status_event(struct uvc_video_chain *chain, + struct uvc_control *ctrl, __u8 *data, size_t len); extern int uvc_ctrl_begin(struct uvc_video_chain *chain); extern int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback, @@ -772,7 +785,7 @@ static inline int uvc_ctrl_rollback(struct uvc_fh *handle) extern int uvc_ctrl_get(struct uvc_video_chain *chain, struct v4l2_ext_control *xctrl); -extern int uvc_ctrl_set(struct uvc_video_chain *chain, +extern int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl); extern int uvc_xu_ctrl_query(struct uvc_video_chain *chain, diff --git a/include/uapi/linux/uvcvideo.h b/include/uapi/linux/uvcvideo.h index 8381ca7c..ee0a5ec 100644 --- a/include/uapi/linux/uvcvideo.h +++ b/include/uapi/linux/uvcvideo.h @@ -27,6 +27,8 @@ #define UVC_CTRL_FLAG_RESTORE (1 << 6) /* Control can be updated by the camera. */ #define UVC_CTRL_FLAG_AUTO_UPDATE (1 << 7) +/* Control supports asynchronous reporting */ +#define UVC_CTRL_FLAG_ASYNCHRONOUS (1 << 8) #define UVC_CTRL_FLAG_GET_RANGE \ (UVC_CTRL_FLAG_GET_CUR | UVC_CTRL_FLAG_GET_MIN | \