Add use_v4lplugin flag to enable v4l2 library

content/common/gpu/media/exynos_v4l2_video_device.cc

Index: content/common/gpu/media/exynos_v4l2_video_device.cc
diff --git a/content/common/gpu/media/exynos_v4l2_video_device.cc b/content/common/gpu/media/exynos_v4l2_video_device.cc
index 214a4311ab39466d8a7b37b9940fa119a8dabadb..20efe2c9e9fbd68b5d66b24402e5c50ae06ea132 100644
--- a/content/common/gpu/media/exynos_v4l2_video_device.cc
+++ b/content/common/gpu/media/exynos_v4l2_video_device.cc
@@ -17,6 +17,29 @@
 #include "content/common/gpu/media/exynos_v4l2_video_device.h"
 #include "ui/gl/gl_bindings.h"
 
+#ifdef USE_LIBV4L2
+#  include<libv4l2.h>

[Pawel Osciak, 2014/11/18 08:36:30]

No indent please. And space before '<'.

[henryhsu, 2014/11/19 03:49:47]

Done.

+#  include "content/common/gpu/media/v4l2_stubs.h"
+
+using content_common_gpu_media::kModuleV4l2;
+using content_common_gpu_media::InitializeStubs;
+using content_common_gpu_media::StubPathMap;
+
+static const base::FilePath::CharType kV4l2Lib[] =
+    FILE_PATH_LITERAL("libv4l2.so");
+#else
+#  define V4L2_DISABLE_CONVERSION 0x01
+#  define v4l2_close close

[Pawel Osciak, 2014/11/18 08:36:30]

No indent please.

[henryhsu, 2014/11/19 03:49:46]

Done.

+#  define v4l2_ioctl ioctl
+#  define v4l2_read read

[Pawel Osciak, 2014/11/18 08:36:29]

We don't use read or write.

[henryhsu, 2014/11/19 03:49:47]

Done.

+#  define v4l2_write write
+#  define v4l2_mmap mmap

[Pawel Osciak, 2014/11/18 08:36:30]

We don't want to do this if we don't do conversion, there is a lot of stuff
going on in there and the mmap call in the library doesn't seem to be checking
for the flag. Is there a fast path through v4l2_mmap if we passed
DISABLE_CONVERSION?
For now I'd remove this. Maybe we can have a patch for the library to ensure
DISABLE_CONVERSION is honored everywhere?

[henryhsu, 2014/11/19 03:49:47]

Agree. use mmap first and then add a patch at the next step.

+#  define v4l2_munmap munmap

[Pawel Osciak, 2014/11/18 08:36:30]

Ditto.

[henryhsu, 2014/11/19 03:49:46]

Done.

+int v4l2_fd_open(int fd, int v4l2_flags) {

[Pawel Osciak, 2014/11/18 08:36:30]

Better just ifdef the call out instead of this and the define for the flag.

[henryhsu, 2014/11/19 03:49:46]

Done.

+  return 0;
+}
+#endif
+
 namespace content {
 
 namespace {
@@ -28,21 +51,28 @@ const char kImageProcessorDevice[] = "/dev/gsc1";
 ExynosV4L2Device::ExynosV4L2Device(Type type)
     : type_(type),
       device_fd_(-1),
-      device_poll_interrupt_fd_(-1) {}
+      device_poll_interrupt_fd_(-1) {
+#ifdef USE_LIBV4L2

[Pawel Osciak, 2014/11/18 08:36:30]

Please extract this to PostSandboxInitialization(). See example at
https://code.google.com/p/chromium/codesearch#chromium/src/content/common/gpu...

[henryhsu, 2014/11/19 03:49:46]

Done.

+  StubPathMap paths;
+  paths[kModuleV4l2].push_back(kV4l2Lib);
+  if (!InitializeStubs(paths))
+    LOG(ERROR) << "Failed to initialize LIBV4L2 libs";

[Pawel Osciak, 2014/11/18 08:36:30]

Shouldn't this be a critical error? Please do this in Initialize() so that we
can return an error.

[henryhsu, 2014/11/19 03:49:46]

Done.

+#endif
+}
 
 ExynosV4L2Device::~ExynosV4L2Device() {
   if (device_poll_interrupt_fd_ != -1) {
-    close(device_poll_interrupt_fd_);
+    v4l2_close(device_poll_interrupt_fd_);

[Pawel Osciak, 2014/11/18 08:36:30]

We should not use v4l2_* functions on interrupt fd, this is not a v4l2 fd.

[henryhsu, 2014/11/19 03:49:47]

Done.

     device_poll_interrupt_fd_ = -1;
   }
   if (device_fd_ != -1) {
-    close(device_fd_);
+    v4l2_close(device_fd_);
     device_fd_ = -1;
   }
 }
 
 int ExynosV4L2Device::Ioctl(int request, void* arg) {
-  return HANDLE_EINTR(ioctl(device_fd_, request, arg));
+  return HANDLE_EINTR(v4l2_ioctl(device_fd_, request, arg));
 }
 
 bool ExynosV4L2Device::Poll(bool poll_device, bool* event_pending) {
@@ -75,18 +105,19 @@ void* ExynosV4L2Device::Mmap(void* addr,
                              int prot,
                              int flags,
                              unsigned int offset) {
-  return mmap(addr, len, prot, flags, device_fd_, offset);
+  return v4l2_mmap(addr, len, prot, flags, device_fd_, offset);
 }
 
 void ExynosV4L2Device::Munmap(void* addr, unsigned int len) {
-  munmap(addr, len);
+  v4l2_munmap(addr, len);
 }
 
 bool ExynosV4L2Device::SetDevicePollInterrupt() {
   DVLOG(3) << "SetDevicePollInterrupt()";
 
   const uint64 buf = 1;
-  if (HANDLE_EINTR(write(device_poll_interrupt_fd_, &buf, sizeof(buf))) == -1) {
+  if (HANDLE_EINTR(
+      v4l2_write(device_poll_interrupt_fd_, &buf, sizeof(buf))) == -1) {
     DPLOG(ERROR) << "SetDevicePollInterrupt(): write() failed";
     return false;
   }
@@ -97,7 +128,8 @@ bool ExynosV4L2Device::ClearDevicePollInterrupt() {
   DVLOG(3) << "ClearDevicePollInterrupt()";
 
   uint64 buf;
-  if (HANDLE_EINTR(read(device_poll_interrupt_fd_, &buf, sizeof(buf))) == -1) {
+  if (HANDLE_EINTR(
+      v4l2_read(device_poll_interrupt_fd_, &buf, sizeof(buf))) == -1) {
     if (errno == EAGAIN) {
       // No interrupt flag set, and we're reading nonblocking.  Not an error.
       return true;
@@ -129,6 +161,10 @@ bool ExynosV4L2Device::Initialize() {
   if (device_fd_ == -1) {
     return false;
   }
+  if (v4l2_fd_open(device_fd_, V4L2_DISABLE_CONVERSION) == -1) {

[Pawel Osciak, 2014/11/18 08:36:30]

Do we need to HANDLE_EINTR?

[henryhsu, 2014/11/19 03:49:47]

Done.

+    v4l2_close(device_fd_);
+    return false;
+  }
 
   device_poll_interrupt_fd_ = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
   if (device_poll_interrupt_fd_ == -1) {