ui/ozone/platform/drm/host/drm_device_handle.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ui/ozone/platform/drm/host/drm_device_handle.h"
   6
   7 #include <fcntl.h>
   8 #include <xf86drm.h>
   9 #include <xf86drmMode.h>
  10
  11 #include "base/files/file_path.h"
  12 #include "base/posix/eintr_wrapper.h"
  13 #include "base/threading/thread_restrictions.h"
  14
  15 namespace ui {
  16
  17 namespace {
  18
  19 bool Authenticate(int fd) {
  20   drm_magic_t magic;
  21   memset(&magic, 0, sizeof(magic));
  22   // We need to make sure the DRM device has enough privilege. Use the DRM
  23   // authentication logic to figure out if the device has enough permissions.
  24   return !drmGetMagic(fd, &magic) && !drmAuthMagic(fd, magic);
  25 }
  26
  27 }  // namespace
  28
  29 DrmDeviceHandle::DrmDeviceHandle() {
  30 }
  31
  32 DrmDeviceHandle::~DrmDeviceHandle() {
  33   if (file_.is_valid())
  34     base::ThreadRestrictions::AssertIOAllowed();
  35 }
  36
  37 bool DrmDeviceHandle::Initialize(const base::FilePath& path) {
  38   CHECK(path.DirName() == base::FilePath("/dev/dri"));
  39   base::ThreadRestrictions::AssertIOAllowed();
  40   bool print_warning = true;
  41   while (true) {
  42     file_.reset();
  43     int fd = HANDLE_EINTR(open(path.value().c_str(), O_RDWR | O_CLOEXEC));
  44     if (fd < 0) {
  45       PLOG(ERROR) << "Failed to open " << path.value();
  46       return false;
  47     }
  48
  49     file_.reset(fd);
  50
  51     if (Authenticate(file_.get()))
  52       break;
  53
  54     LOG_IF(WARNING, print_warning) << "Failed to authenticate " << path.value();
  55     print_warning = false;
  56     usleep(100000);
  57   }
  58
  59   VLOG(1) << "Succeeded authenticating " << path.value();
  60   return true;
  61 }
  62
  63 bool DrmDeviceHandle::IsValid() const {
  64   return file_.is_valid();
  65 }
  66
  67 base::ScopedFD DrmDeviceHandle::PassFD() {
  68   return file_.Pass();
  69 }
  70
  71 }  // namespace ui