Merge "Add some error logs for FdTrigger errors" into main am: eaf71ed468 am: 70822d3927

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/3260554

Change-Id: Id4ecbc160b65274c2ab4defdfd446869e1f6b750
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/libs/binder/FdTrigger.cpp b/libs/binder/FdTrigger.cpp
index 455a433..f0aa801 100644
--- a/libs/binder/FdTrigger.cpp
+++ b/libs/binder/FdTrigger.cpp
@@ -82,7 +82,9 @@
 
     int ret = TEMP_FAILURE_RETRY(poll(pfd, countof(pfd), -1));
     if (ret < 0) {
-        return -errno;
+        int saved_errno = errno;
+        ALOGE("FdTrigger poll returned error: %d, with error: %s", ret, strerror(saved_errno));
+        return -saved_errno;
     }
     LOG_ALWAYS_FATAL_IF(ret == 0, "poll(%d) returns 0 with infinite timeout", transportFd.fd.get());
 
@@ -106,6 +108,7 @@
 
     // POLLNVAL: invalid FD number, e.g. not opened.
     if (pfd[0].revents & POLLNVAL) {
+        ALOGE("Invalid FD number (%d) in FdTrigger (POLLNVAL)", pfd[0].fd);
         return BAD_VALUE;
     }