[PATCH libdrm v3] modetest: Use floating vrefresh while dumping mode

[Devarsh Thakkar]

Add function to derive floating value of vertical
refresh rate from drm mode using pixel clock,
horizontal total size and vertical total size.

Use this function to find suitable mode having vrefresh
value which is matching with user provided vrefresh value.

If user doesn't provide any vrefresh value in args then
update vertical refresh rate value in pipe args using this
function.

Also use this function for printing floating vrefresh while
dumping all available modes.

This will give more accurate picture to user for available modes
differentiated by floating vertical refresh rate and help user
select more appropriate mode using suitable refresh rate value.

V3: Change name of function used to derive refresh rate.
V2: 1) Don't use inline function for deriving refresh rate from mode.
    2) If requested mode not found, print refresh rate only
       if user had provided it in args.

Signed-off-by: Devarsh Thakkar <devarsh.thakkar at xilinx.com>
---
 tests/modetest/modetest.c | 40 +++++++++++++++++++++++++++-------------
 1 file changed, 27 insertions(+), 13 deletions(-)

diff --git a/tests/modetest/modetest.c b/tests/modetest/modetest.c
index b4edfcb..19ce20f 100644
--- a/tests/modetest/modetest.c
+++ b/tests/modetest/modetest.c
@@ -133,6 +133,12 @@ static inline int64_t U642I64(uint64_t val)
 	return (int64_t)*((int64_t *)&val);
 }
 
+static float mode_vrefresh(drmModeModeInfo *mode)
+{
+	return  mode->clock * 1000.00
+			/ (mode->htotal * mode->vtotal);
+}
+
 #define bit_name_fn(res)					\
 const char * res##_str(int type) {				\
 	unsigned int i;						\
@@ -210,9 +216,9 @@ static void dump_encoders(struct device *dev)
 
 static void dump_mode(drmModeModeInfo *mode)
 {
-	printf("  %s %d %d %d %d %d %d %d %d %d %d",
+	printf("  %s %.2f %d %d %d %d %d %d %d %d %d",
 	       mode->name,
-	       mode->vrefresh,
+	       mode_vrefresh(mode),
 	       mode->hdisplay,
 	       mode->hsync_start,
 	       mode->hsync_end,
@@ -823,12 +829,11 @@ struct plane_arg {
 
 static drmModeModeInfo *
 connector_find_mode(struct device *dev, uint32_t con_id, const char *mode_str,
-	const float vrefresh)
+	float *vrefresh)
 {
 	drmModeConnector *connector;
 	drmModeModeInfo *mode;
 	int i;
-	float mode_vrefresh;
 
 	connector = get_connector_by_id(dev, con_id);
 	if (!connector || !connector->count_modes)
@@ -837,16 +842,19 @@ connector_find_mode(struct device *dev, uint32_t con_id, const char *mode_str,
 	for (i = 0; i < connector->count_modes; i++) {
 		mode = &connector->modes[i];
 		if (!strcmp(mode->name, mode_str)) {
-			/* If the vertical refresh frequency is not specified then return the
-			 * first mode that match with the name. Else, return the mode that match
-			 * the name and the specified vertical refresh frequency.
+			/* If the vertical refresh frequency is not specified
+			 * then return the first mode that match with the name
+			 * and update corresponding vrefresh in pipe_arg.
+			 * Else, return the mode that match the name and
+			 * the specified vertical refresh frequency.
 			 */
-			mode_vrefresh = mode->clock * 1000.00
-					/ (mode->htotal * mode->vtotal);
-			if (vrefresh == 0)
+			if (*vrefresh == 0) {
+				*vrefresh = mode_vrefresh(mode);
 				return mode;
-			else if (fabs(mode_vrefresh - vrefresh) < 0.005)
+			} else if (fabs(mode_vrefresh(mode)
+				   - *vrefresh) < 0.005) {
 				return mode;
+			}
 		}
 	}
 
@@ -909,9 +917,15 @@ static int pipe_find_crtc_and_mode(struct device *dev, struct pipe_arg *pipe)
 
 	for (i = 0; i < (int)pipe->num_cons; i++) {
 		mode = connector_find_mode(dev, pipe->con_ids[i],
-					   pipe->mode_str, pipe->vrefresh);
+					   pipe->mode_str, &pipe->vrefresh);
 		if (mode == NULL) {
-			fprintf(stderr,
+			if (pipe->vrefresh)
+				fprintf(stderr,
+				"failed to find mode "
+				"\"%s-%.2fHz\" for connector %s\n",
+				pipe->mode_str, pipe->vrefresh, pipe->cons[i]);
+			else
+				fprintf(stderr,
 				"failed to find mode \"%s\" for connector %s\n",
 				pipe->mode_str, pipe->cons[i]);
 			return -EINVAL;
-- 
2.7.4