[Intel-gfx] [PATCH] drm: Fix for invalid pruning of modes in dual display cases

[Vidya Srinivas]

Currently in dual display connected boot scenarios, minimum of the resolutions
is taken for fb width and height as reference. Based on this resolution, other
modes are pruned.

Example Scenario: If DSI mode is 2560x1440 and HDMI is 1920x1080, during the probing
the fb width and height is set to max 1920x1080 and the DSI mode gets pruned as it is
more than the reference. As a result, there is no DSI display.
Patch fixes this issue by taking the max of the resolutions and creating the fb
based on the same.

Signed-off-by: Vidya Srinivas <vidya.srinivas at intel.com>
Signed-off-by: Uma Shankar <uma.shankar at intel.com>
---
 drivers/gpu/drm/drm_fb_helper.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index e934b54..6afc06f 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1482,8 +1482,8 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
 	memset(&sizes, 0, sizeof(struct drm_fb_helper_surface_size));
 	sizes.surface_depth = 24;
 	sizes.surface_bpp = 32;
-	sizes.fb_width = (unsigned)-1;
-	sizes.fb_height = (unsigned)-1;
+	sizes.fb_width = 0;
+	sizes.fb_height = 0;
 
 	/* if driver picks 8 or 16 by default use that
 	   for both depth/bpp */
@@ -1560,9 +1560,9 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper,
 		}
 
 		if (lasth)
-			sizes.fb_width  = min_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
+			sizes.fb_width  = max_t(u32, desired_mode->hdisplay + x, sizes.fb_width);
 		if (lastv)
-			sizes.fb_height = min_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
+			sizes.fb_height = max_t(u32, desired_mode->vdisplay + y, sizes.fb_height);
 	}
 
 	if (crtc_count == 0 || sizes.fb_width == -1 || sizes.fb_height == -1) {
-- 
1.9.1