drm_hwcomposer: Improve error messages.

- Don't negate errno before passing to strerror, at least on
  bionic this results in "Unknown error -x" instead of the actual
  error.
- Fix another error message to print strerror(errno) instead of the
  returned fd which will always be -1.
- Fix another error message to call strerror for consistency.

Signed-off-by: Peter Collingbourne <pcc@google.com>

2 files changed, 3 insertions, 3 deletions

diff --git a/drm/drmdevice.cpp b/drm/drmdevice.cpp
index bcb9ddd..bef41d8 100644
--- a/drm/drmdevice.cpp
+++ b/drm/drmdevice.cpp
@@ -126,7 +126,7 @@ std::tuple<int, int> DrmDevice::Init(const char *path, int num_displays) {
   /* TODO: Use drmOpenControl here instead */
   fd_.Set(open(path, O_RDWR));
   if (fd() < 0) {
-    ALOGE("Failed to open dri- %s", strerror(-errno));
+    ALOGE("Failed to open dri %s: %s", path, strerror(errno));
     return std::make_tuple(-ENODEV, 0);
   }
 
diff --git a/drm/drmeventlistener.cpp b/drm/drmeventlistener.cpp
index 8f655a7..ccee0d6 100644
--- a/drm/drmeventlistener.cpp
+++ b/drm/drmeventlistener.cpp
@@ -38,7 +38,7 @@ DrmEventListener::DrmEventListener(DrmDevice *drm)
 int DrmEventListener::Init() {
   uevent_fd_.Set(socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT));
   if (uevent_fd_.get() < 0) {
-    ALOGE("Failed to open uevent socket %d", uevent_fd_.get());
+    ALOGE("Failed to open uevent socket: %s", strerror(errno));
     return uevent_fd_.get();
   }
 
@@ -50,7 +50,7 @@ int DrmEventListener::Init() {
 
   int ret = bind(uevent_fd_.get(), (struct sockaddr *)&addr, sizeof(addr));
   if (ret) {
-    ALOGE("Failed to bind uevent socket %d", -errno);
+    ALOGE("Failed to bind uevent socket: %s", strerror(errno));
     return -errno;
   }