From b91c42837046875cd41420d6d87c5428c2dac31a Mon Sep 17 00:00:00 2001
From: tonton th <sigfood@dinorama.fr>
Date: Sun, 28 Feb 2021 18:18:26 +0100
Subject: [PATCH] opening a raspi bug hunt

---
 v4l2/grabvidseq.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/v4l2/grabvidseq.c b/v4l2/grabvidseq.c
index 16b0acf8..9ef351ca 100644
--- a/v4l2/grabvidseq.c
+++ b/v4l2/grabvidseq.c
@@ -46,7 +46,8 @@ struct buffer {
 	size_t length;
 	};
 
-int		verbosity;
+int			verbosity;
+static int		systrace;
 
 /* --------------------------------------------------------------------- */
 
@@ -54,6 +55,11 @@ static void xioctl(int fh, int request, void *arg)
 {
 int	r;
 
+/* may be imagine a system for displaying all call to this function ? */
+if (systrace) {
+	fprintf(stderr, "xioctl fd=%d req=%d arg=%p\n", fh, request, arg);
+	}
+
 do	{
 	r = v4l2_ioctl(fh, request, arg);
 	} while (r == -1 && ((errno == EINTR) || (errno == EAGAIN)));
@@ -83,6 +89,7 @@ puts("\t-s WxH\t\tsize of capture");
 puts("\t-c mode\t\tcontrast enhancement");
 puts("\t-u\t\ttry upscaling...");
 puts("\t-v\t\tincrease verbosity");
+puts("\t-Z\t\tenable systrace");
 if (verbosity) {
 	puts("\n\t\tXXX list all the contrast modes, please\n");
 	}
@@ -124,7 +131,7 @@ char		*outfile = "out.pnm";
 FloatImg	cumul, tmpfimg, *to_save;
 #endif
 
-while ((opt = getopt(argc, argv, "c:d:ghn:o:O:p:r:s:uv")) != -1) {
+while ((opt = getopt(argc, argv, "c:d:ghn:o:O:p:r:s:uvZ")) != -1) {
 	switch(opt) {
 		case 'c':	contrast = fimg_id_contraste(optarg);
 				if (contrast < 0) {
@@ -151,7 +158,7 @@ while ((opt = getopt(argc, argv, "c:d:ghn:o:O:p:r:s:uv")) != -1) {
 				break;
 		case 'u':	upscaling = 1;			break;
 		case 'v':	verbosity++;			break;
-
+		case 'Z':	systrace = 1;			break;
 		default:
 			fprintf(stderr, "option '%c' is wtf\n", opt);
 			exit(1);