drm/radeon: make sure vertical front porch is at least 1

commit 3104b8128d4d646a574ed9d5b17c7d10752cd70b upstream.

hw doesn't like a 0 value.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alex Deucher 2016-05-02 18:53:27 -04:00 committed by Greg Kroah-Hartman
parent 0f5c3afc75
commit 6b5f7a680d

@ -310,6 +310,10 @@ static bool radeon_atom_mode_fixup(struct drm_encoder *encoder,
&& (mode->crtc_vsync_start < (mode->crtc_vdisplay + 2)))
adjusted_mode->crtc_vsync_start = adjusted_mode->crtc_vdisplay + 2;
/* vertical FP must be at least 1 */
if (mode->crtc_vsync_start == mode->crtc_vdisplay)
adjusted_mode->crtc_vsync_start++;
/* get the native mode for scaling */
if (radeon_encoder->active_device & (ATOM_DEVICE_LCD_SUPPORT)) {
radeon_panel_mode_fixup(encoder, adjusted_mode);