[PATCH 4/4] drm/i915: use current mode if the size matches the preferred mode

Jesse Barnes
2014-10-09T20:06:44Z

From: Kristian Høgsberg <hoegsberg@gmail.com>

The BIOS may set a native mode that doesn't quite match the preferred
mode timings. It should be ok to use however if it uses the same size,
so try to avoid a mode set in that case.

Signed-off-by: Kristian Høgsberg <hoegsberg@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
drivers/gpu/drm/i915/intel_fbdev.c | 47 +++++++++++++++-----------------------
1 file changed, 18 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index 9b584f3..79dd814 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -398,42 +398,31 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
/* go for command line mode first */
modes[i] = drm_pick_cmdline_mode(fb_conn, width, height);

- /* try for preferred next */
+ /* try for preferred next or match current */
if (!modes[i]) {
- DRM_DEBUG_KMS("looking for preferred mode on connector %s\n",
- connector->name);
- modes[i] = drm_has_preferred_mode(fb_conn, width,
- height);
- }
+ struct drm_display_mode *preferred;

- /* No preferred mode marked by the EDID? Are there any modes? */
- if (!modes[i] && !list_empty(&connector->modes)) {
- DRM_DEBUG_KMS("using first mode listed on connector %s\n",
+ DRM_DEBUG_KMS("looking for preferred mode on connector %s\n",
connector->name);
- modes[i] = list_first_entry(&connector->modes,
- struct drm_display_mode,
- head);
- }
+ preferred = drm_has_preferred_mode(fb_conn, width,
+ height);

- /* last resort: use current mode */
- if (!modes[i]) {
- /*
- * IMPORTANT: We want to use the adjusted mode (i.e.
- * after the panel fitter upscaling) as the initial
- * config, not the input mode, which is what crtc->mode
- * usually contains. But since our current fastboot
- * code puts a mode derived from the post-pfit timings
- * into crtc->mode this works out correctly. We don't
- * use hwmode anywhere right now, so use it for this
- * since the fb helper layer wants a pointer to
- * something we own.
- */
- DRM_DEBUG_KMS("looking for current mode on connector %s\n",
- connector->name);
intel_mode_from_pipe_config(&encoder->crtc->hwmode,
&to_intel_crtc(encoder->crtc)->config);
- modes[i] = &encoder->crtc->hwmode;
+ modes[i] = &encoder->crtc->hwmode;
+
+ if (preferred &&
+ !drm_mode_same_size(preferred, modes[i])) {
+ DRM_DEBUG_KMS("using preferred mode %s "
+ "instead of current mode %s "
+ "on connector %d\n",
+ preferred->name,
+ modes[i]->name,
+ fb_conn->connector->base.id);
+ modes[i] = preferred;
+ }
}
+
crtcs[i] = new_crtc;

DRM_DEBUG_KMS("connector %s on pipe %c [CRTC:%d]: %dx%d%s\n",
--
1.9.1