drm/fb: Fix video= mode computation

Reduced blanking is valid only when doing CVT modes.  Also, generate GTF
modes unless CVT was requested; CVT devices are required to support GTF,
but the reverse is not true.

[airlied: fix typo]

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 13 insertions, 6 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 08c4c926e65f..1f2cc6b09623 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -146,7 +146,7 @@ static bool drm_fb_helper_connector_parse_command_line(struct drm_fb_helper_conn
                                 cvt = 1;
                         break;
                 case 'R':
-                        if (!cvt)
+                        if (cvt)
                                 rb = 1;
                         break;
                 case 'm':
@@ -1024,11 +1024,18 @@ static struct drm_display_mode *drm_pick_cmdline_mode(struct drm_fb_helper_conne
         }
 
 create_mode:
-        mode = drm_cvt_mode(fb_helper_conn->connector->dev, cmdline_mode->xres,
-                            cmdline_mode->yres,
-                            cmdline_mode->refresh_specified ? cmdline_mode->refresh : 60,
-                            cmdline_mode->rb, cmdline_mode->interlace,
-                            cmdline_mode->margins);
+        if (cmdline_mode->cvt)
+                mode = drm_cvt_mode(fb_helper_conn->connector->dev,
+                                    cmdline_mode->xres, cmdline_mode->yres,
+                                    cmdline_mode->refresh_specified ? cmdline_mode->refresh : 60,
+                                    cmdline_mode->rb, cmdline_mode->interlace,
+                                    cmdline_mode->margins);
+        else
+                mode = drm_gtf_mode(fb_helper_conn->connector->dev,
+                                    cmdline_mode->xres, cmdline_mode->yres,
+                                    cmdline_mode->refresh_specified ? cmdline_mode->refresh : 60,
+                                    cmdline_mode->interlace,
+                                    cmdline_mode->margins);
         drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
         list_add(&mode->head, &fb_helper_conn->connector->modes);
         return mode;