ui: Reduce logging in ui::ClientNativePixmapDmaBuf.

ui/ozone/platform/drm/common/client_native_pixmap_dmabuf.cc

 // Copyright 2016 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 "ui/ozone/platform/drm/common/client_native_pixmap_dmabuf.h"
 
 #include <fcntl.h>
 #include <linux/version.h>
 #include <stddef.h>
 #include <sys/mman.h>
@@ skipping 22 matching lines @@
 
 #define LOCAL_DMA_BUF_BASE 'b'
 #define LOCAL_DMA_BUF_IOCTL_SYNC \
   _IOW(LOCAL_DMA_BUF_BASE, 0, struct local_dma_buf_sync)
 
 #else
 #include <linux/dma-buf.h>
 #endif
 
 namespace ui {
-
 namespace {
 
-void PrimeSyncStart(int dmabuf_fd) {
+bool PrimeSyncStart(int dmabuf_fd) {
   struct local_dma_buf_sync sync_start = {0};
 
   sync_start.flags = LOCAL_DMA_BUF_SYNC_START | LOCAL_DMA_BUF_SYNC_RW;
-  if (drmIoctl(dmabuf_fd, LOCAL_DMA_BUF_IOCTL_SYNC, &sync_start))
-    PLOG(ERROR) << "Failed DMA_BUF_SYNC_START";
+  return !drmIoctl(dmabuf_fd, LOCAL_DMA_BUF_IOCTL_SYNC, &sync_start);
 }
 
-void PrimeSyncEnd(int dmabuf_fd) {
+bool PrimeSyncEnd(int dmabuf_fd) {
   struct local_dma_buf_sync sync_end = {0};
 
   sync_end.flags = LOCAL_DMA_BUF_SYNC_END | LOCAL_DMA_BUF_SYNC_RW;
-  if (drmIoctl(dmabuf_fd, LOCAL_DMA_BUF_IOCTL_SYNC, &sync_end))
-    PLOG(ERROR) << "Failed DMA_BUF_SYNC_END";
+  return !drmIoctl(dmabuf_fd, LOCAL_DMA_BUF_IOCTL_SYNC, &sync_end);
 }
 
 }  // namespace
 
 // static
 std::unique_ptr<ClientNativePixmap> ClientNativePixmapDmaBuf::ImportFromDmabuf(
     const gfx::NativePixmapHandle& handle,
     const gfx::Size& size) {
   return base::WrapUnique(new ClientNativePixmapDmaBuf(handle, size));
 }
@@ skipping 47 matching lines @@
   TRACE_EVENT0("drm", "~ClientNativePixmapDmaBuf");
   size_t map_size =
       pixmap_handle_.planes.back().offset + pixmap_handle_.planes.back().size;
   int ret = munmap(data_, map_size);
   DCHECK(!ret);
 }
 
 bool ClientNativePixmapDmaBuf::Map() {
   TRACE_EVENT0("drm", "DmaBuf:Map");
   if (data_ != nullptr) {
-    PrimeSyncStart(dmabuf_fd_.get());
+    bool rv = PrimeSyncStart(dmabuf_fd_.get());
+    PLOG_IF(ERROR, !rv && !map_count_) << "PrimeSyncStart Failed";
     return true;
   }
   return false;
 }
 
 void ClientNativePixmapDmaBuf::Unmap() {
   TRACE_EVENT0("drm", "DmaBuf:Unmap");
-  PrimeSyncEnd(dmabuf_fd_.get());
+  bool rv = PrimeSyncEnd(dmabuf_fd_.get());
+  PLOG_IF(ERROR, !rv && !map_count_) << "PrimeSyncEnd Failed";
+  ++map_count_;

[Daniele Castagna, 2017/03/24 00:53:10]

nit: If we increment it here it's not really a map count (i.e: if someones calls
map once then map_count is still 0).
Can we think of a better name than map_count_?

Another option could be to increment it in map and log only when map_count_ is
1.

 }
 
 void* ClientNativePixmapDmaBuf::GetMemoryAddress(size_t plane) const {
   DCHECK_LT(plane, pixmap_handle_.planes.size());
   uint8_t* address = reinterpret_cast<uint8_t*>(data_);
   return address + pixmap_handle_.planes[plane].offset;
 }
 
 int ClientNativePixmapDmaBuf::GetStride(size_t plane) const {
   DCHECK_LT(plane, pixmap_handle_.planes.size());
   return pixmap_handle_.planes[plane].stride;
 }
 
 }  // namespace ui