ImageCapture v4l2: reset user controls when opening the device

media/capture/video/linux/v4l2_capture_delegate.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/capture/video/linux/v4l2_capture_delegate.h"
 
 #include <linux/version.h>
 #include <linux/videodev2.h>
 #include <poll.h>
 #include <sys/fcntl.h>
@@ skipping 340 matching lines @@
   client_ = std::move(client);
 
   // Need to open camera with O_RDWR after Linux kernel 3.3.
   device_fd_.reset(
       HANDLE_EINTR(open(device_descriptor_.device_id.c_str(), O_RDWR)));
   if (!device_fd_.is_valid()) {
     SetErrorState(FROM_HERE, "Failed to open V4L2 device driver file.");
     return;
   }
 
+  ResetUserAndCameraControlsToDefault(device_fd_.get());
+
   v4l2_capability cap = {};
   if (!((HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_QUERYCAP, &cap)) == 0) &&
         ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) &&
          !(cap.capabilities & V4L2_CAP_VIDEO_OUTPUT)))) {
     device_fd_.reset();
     SetErrorState(FROM_HERE, "This is not a V4L2 video capture device");
     return;
   }
 
   // Get supported video formats in preferred order. For large resolutions,
@@ skipping 110 matching lines @@
     return;
   }
 
   buffer_tracker_pool_.clear();
 
   v4l2_requestbuffers r_buffer;
   FillV4L2RequestBuffer(&r_buffer, 0);
   if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_REQBUFS, &r_buffer)) < 0)
     SetErrorState(FROM_HERE, "Failed to VIDIOC_REQBUFS with count = 0");
 
-  ResetUserAndCameraControlsToDefault(device_fd_.get());
   // At this point we can close the device.
   // This is also needed for correctly changing settings later via VIDIOC_S_FMT.
   device_fd_.reset();
   is_capturing_ = false;
   client_.reset();
 }
 
 void V4L2CaptureDelegate::TakePhoto(
     VideoCaptureDevice::TakePhotoCallback callback) {
   DCHECK(v4l2_task_runner_->BelongsToCurrentThread());
@@ skipping 278 matching lines @@
     DLOG(ERROR) << "Error mmap()ing a V4L2 buffer into userspace";
     return false;
   }
   start_ = static_cast<uint8_t*>(start);
   length_ = buffer.length;
   payload_size_ = 0;
   return true;
 }
 
 }  // namespace media