Re: [PATCH] v4l2-dbg: report fail reason to the user

["Németh Márton" <nm127@freemail.hu>]

From: Márton Németh <nm127@freemail.hu>

Report the fail reason to the user when writing a register even if
the verbose mode is switched off.

Remove duplicated code ioctl() call which may cause different ioctl()
function call in case of verbose and non verbose if not handled carefully.

Signed-off-by: Márton Németh <nm127@freemail.hu>
---
diff -r 60f784aa071d v4l2-apps/util/v4l2-dbg.cpp
--- a/v4l2-apps/util/v4l2-dbg.cpp	Wed Nov 11 18:28:53 2009 +0100
+++ b/v4l2-apps/util/v4l2-dbg.cpp	Thu Nov 12 08:21:20 2009 +0100
@@ -353,14 +353,21 @@
 static int doioctl(int fd, int request, void *parm, const char *name)
 {
 	int retVal;
+	int ioctl_errno;

 	if (!options[OptVerbose]) return ioctl(fd, request, parm);
 	retVal = ioctl(fd, request, parm);
-	printf("%s: ", name);
-	if (retVal < 0)
-		printf("failed: %s\n", strerror(errno));
-	else
-		printf("ok\n");
+	if (options[OptVerbose]) {
+		/* Save errno because printf() may modify it */
+		ioctl_errno = errno;
+		printf("%s: ", name);
+		if (retVal < 0)
+			printf("failed: %s\n", strerror(errno));
+		else
+			printf("ok\n");
+		/* Restore errno for caller's use */
+		errno = ioctl_errno;
+	}

 	return retVal;
 }
@@ -586,8 +593,8 @@

 				printf(" set to 0x%llx\n", set_reg.val);
 			} else {
-				printf("Failed to set register 0x%08llx value 0x%llx\n",
-					set_reg.reg, set_reg.val);
+				printf("Failed to set register 0x%08llx value 0x%llx: %s\n",
+					set_reg.reg, set_reg.val, strerror(errno));
 			}
 			set_reg.reg++;
 		}