On Thu, 17 May 2018, Jani Nikula <jani.nikula@xxxxxxxxx> wrote: > On Wed, 16 May 2018, Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> wrote: >> On Wed, 2018-05-16 at 11:01 +0300, Jani Nikula wrote: >>> This reverts commit dc911f5bd8aacfcf8aabd5c26c88e04c837a938e. >>> >>> Per the report, no matter what display mode you select with xrandr, >>> the >>> i915 driver will always select the alternate fixed mode. For the >>> reporter this means that the display will always run at 40Hz which is >>> quite annoying. This may be due to the mode comparison. >>> >>> But there are some other potential issues. The choice of >>> alt_fixed_mode >>> seems dubious. It's the first non-preferred mode, but there are no >>> guarantees that the only difference would be refresh rate. Similarly, >>> there may be more than one preferred mode in the probed modes list, >>> and >>> the commit changes the preferred mode selection to choose the last >>> one >>> on the list instead of the first. >>> >>> (Note that the probed modes list is the raw, unfiltered, unsorted >>> list >>> of modes from drm_add_edid_modes(), not the pretty result after a >>> drm_helper_probe_single_connector_modes() call.) >>> >>> Finally, we already have eerily similar code in place to find the >>> downclock mode for DRRS that seems like could be reused here. >>> >>> Back to the drawing board. >>> >>> Note: This is a hand-crafted revert due to conflicts. If it fails to >>> backport, please just try reverting the original commit directly. >>> >>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105469 >>> Reported-by: Rune Petersen <rune@xxxxxxxxxxxx> >>> Reported-by: Mark Spencer <n7u4722r35@xxxxxxxxxxxxxxxxx> >>> Fixes: dc911f5bd8aa ("drm/i915/edp: Allow alternate fixed mode for >>> eDP if available.") >>> Cc: Clint Taylor <clinton.a.taylor@xxxxxxxxx> >>> Cc: David Weinehall <david.weinehall@xxxxxxxxxxxxxxx> >>> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> >>> Cc: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> >>> Cc: Jani Nikula <jani.nikula@xxxxxxxxx> >>> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >>> Cc: Jim Bride <jim.bride@xxxxxxxxxxxxxxx> >>> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> >>> Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> >>> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx >>> Cc: <stable@xxxxxxxxxxxxxxx> # v4.14+ >>> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> >>> --- >>> drivers/gpu/drm/i915/intel_dp.c | 38 +++++----------------------- >>> ---------- >>> drivers/gpu/drm/i915/intel_drv.h | 2 -- >>> drivers/gpu/drm/i915/intel_dsi.c | 2 +- >>> drivers/gpu/drm/i915/intel_dvo.c | 2 +- >>> drivers/gpu/drm/i915/intel_lvds.c | 3 +-- >>> drivers/gpu/drm/i915/intel_panel.c | 6 ------ >>> 6 files changed, 8 insertions(+), 45 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/i915/intel_dp.c >>> b/drivers/gpu/drm/i915/intel_dp.c >>> index dde92e4af5d3..8320f0e8e3be 100644 >>> --- a/drivers/gpu/drm/i915/intel_dp.c >>> +++ b/drivers/gpu/drm/i915/intel_dp.c >>> @@ -1679,23 +1679,6 @@ static int intel_dp_compute_bpp(struct >>> intel_dp *intel_dp, >>> return bpp; >>> } >>> >>> -static bool intel_edp_compare_alt_mode(struct drm_display_mode *m1, >>> - struct drm_display_mode *m2) >>> -{ >>> - bool bres = false; >>> - >>> - if (m1 && m2) >>> - bres = (m1->hdisplay == m2->hdisplay && >>> - m1->hsync_start == m2->hsync_start && >>> - m1->hsync_end == m2->hsync_end && >>> - m1->htotal == m2->htotal && >>> - m1->vdisplay == m2->vdisplay && >>> - m1->vsync_start == m2->vsync_start && >>> - m1->vsync_end == m2->vsync_end && >>> - m1->vtotal == m2->vtotal); >>> - return bres; >>> -} >>> - >>> /* Adjust link config limits based on compliance test requests. */ >>> static void >>> intel_dp_adjust_compliance_config(struct intel_dp *intel_dp, >>> @@ -1860,16 +1843,8 @@ intel_dp_compute_config(struct intel_encoder >>> *encoder, >>> pipe_config->has_audio = intel_conn_state- >>> >force_audio == HDMI_AUDIO_ON; >>> >>> if (intel_dp_is_edp(intel_dp) && intel_connector- >>> >panel.fixed_mode) { >>> - struct drm_display_mode *panel_mode = >>> - intel_connector->panel.alt_fixed_mode; >>> - struct drm_display_mode *req_mode = &pipe_config- >>> >base.mode; >>> - >>> - if (!intel_edp_compare_alt_mode(req_mode, >>> panel_mode)) >>> - panel_mode = intel_connector- >>> >panel.fixed_mode; >>> - >>> - drm_mode_debug_printmodeline(panel_mode); >>> - >>> - intel_fixed_panel_mode(panel_mode, adjusted_mode); >>> + intel_fixed_panel_mode(intel_connector- >>> >panel.fixed_mode, >>> + adjusted_mode); >>> >>> if (INTEL_GEN(dev_priv) >= 9) { >>> int ret; >>> @@ -6159,7 +6134,6 @@ static bool intel_edp_init_connector(struct >>> intel_dp *intel_dp, >>> struct drm_i915_private *dev_priv = to_i915(dev); >>> struct drm_connector *connector = &intel_connector->base; >>> struct drm_display_mode *fixed_mode = NULL; >>> - struct drm_display_mode *alt_fixed_mode = NULL; >>> struct drm_display_mode *downclock_mode = NULL; >>> bool has_dpcd; >>> struct drm_display_mode *scan; >>> @@ -6214,14 +6188,13 @@ static bool intel_edp_init_connector(struct >>> intel_dp *intel_dp, >>> } >>> intel_connector->edid = edid; >>> >>> - /* prefer fixed mode from EDID if available, save an alt >>> mode also */ >>> + /* prefer fixed mode from EDID if available */ >>> list_for_each_entry(scan, &connector->probed_modes, head) { >>> if ((scan->type & DRM_MODE_TYPE_PREFERRED)) { >>> fixed_mode = drm_mode_duplicate(dev, scan); >>> downclock_mode = intel_dp_drrs_init( >>> intel_connector, >>> fixed_mode); >>> - } else if (!alt_fixed_mode) { >>> - alt_fixed_mode = drm_mode_duplicate(dev, >>> scan); >>> + break; >> >> If multiple preferred modes are present, we'll now end up calling >> drrs_init() only for the first. I see that this is what the original >> code did but this revert does more than removing support for alternate >> modes. > > It boils down to which preferred mode is *the* preferred mode. I think > the original code was, uh, preferrable. Note that drrs init scans the > entire list of modes again to find the same size mode with the lowest > refresh rate. Moreover, as you can see, the original alt mode commit had more subtle changes than catches the eye, it caused regressions, and I feel pretty strongly about getting back to the drawing board and starting over with a clean slate than trying to tweak it when we are quite frankly way overdue with the revert. If after that you think the drrs/downclock selection needs tweaking, let's do that. BR, Jani. > > BR, > Jani. > >> >>> } >>> } >>> >>> @@ -6258,8 +6231,7 @@ static bool intel_edp_init_connector(struct >>> intel_dp *intel_dp, >>> pipe_name(pipe)); >>> } >>> >>> - intel_panel_init(&intel_connector->panel, fixed_mode, >>> alt_fixed_mode, >>> - downclock_mode); >>> + intel_panel_init(&intel_connector->panel, fixed_mode, >>> downclock_mode); >>> intel_connector->panel.backlight.power = >>> intel_edp_backlight_power; >>> intel_panel_setup_backlight(connector, pipe); >>> >>> diff --git a/drivers/gpu/drm/i915/intel_drv.h >>> b/drivers/gpu/drm/i915/intel_drv.h >>> index d7dbca1aabff..0361130500a6 100644 >>> --- a/drivers/gpu/drm/i915/intel_drv.h >>> +++ b/drivers/gpu/drm/i915/intel_drv.h >>> @@ -277,7 +277,6 @@ struct intel_encoder { >>> >>> struct intel_panel { >>> struct drm_display_mode *fixed_mode; >>> - struct drm_display_mode *alt_fixed_mode; >>> struct drm_display_mode *downclock_mode; >>> >>> /* backlight */ >>> @@ -1850,7 +1849,6 @@ void intel_overlay_reset(struct >>> drm_i915_private *dev_priv); >>> /* intel_panel.c */ >>> int intel_panel_init(struct intel_panel *panel, >>> struct drm_display_mode *fixed_mode, >>> - struct drm_display_mode *alt_fixed_mode, >>> struct drm_display_mode *downclock_mode); >>> void intel_panel_fini(struct intel_panel *panel); >>> void intel_fixed_panel_mode(const struct drm_display_mode >>> *fixed_mode, >>> diff --git a/drivers/gpu/drm/i915/intel_dsi.c >>> b/drivers/gpu/drm/i915/intel_dsi.c >>> index 51a1d6868b1e..cf39ca90d887 100644 >>> --- a/drivers/gpu/drm/i915/intel_dsi.c >>> +++ b/drivers/gpu/drm/i915/intel_dsi.c >>> @@ -1846,7 +1846,7 @@ void intel_dsi_init(struct drm_i915_private >>> *dev_priv) >>> connector->display_info.width_mm = fixed_mode->width_mm; >>> connector->display_info.height_mm = fixed_mode->height_mm; >>> >>> - intel_panel_init(&intel_connector->panel, fixed_mode, NULL, >>> NULL); >>> + intel_panel_init(&intel_connector->panel, fixed_mode, NULL); >>> intel_panel_setup_backlight(connector, INVALID_PIPE); >>> >>> intel_dsi_add_properties(intel_connector); >>> diff --git a/drivers/gpu/drm/i915/intel_dvo.c >>> b/drivers/gpu/drm/i915/intel_dvo.c >>> index eb0c559b2715..a70d767313aa 100644 >>> --- a/drivers/gpu/drm/i915/intel_dvo.c >>> +++ b/drivers/gpu/drm/i915/intel_dvo.c >>> @@ -536,7 +536,7 @@ void intel_dvo_init(struct drm_i915_private >>> *dev_priv) >>> */ >>> intel_panel_init(&intel_connector->panel, >>> intel_dvo_get_current_mode( >>> intel_encoder), >>> - NULL, NULL); >>> + NULL); >>> intel_dvo->panel_wants_dither = true; >>> } >>> >>> diff --git a/drivers/gpu/drm/i915/intel_lvds.c >>> b/drivers/gpu/drm/i915/intel_lvds.c >>> index 8691c86f579c..d8ece907ff54 100644 >>> --- a/drivers/gpu/drm/i915/intel_lvds.c >>> +++ b/drivers/gpu/drm/i915/intel_lvds.c >>> @@ -1140,8 +1140,7 @@ void intel_lvds_init(struct drm_i915_private >>> *dev_priv) >>> out: >>> mutex_unlock(&dev->mode_config.mutex); >>> >>> - intel_panel_init(&intel_connector->panel, fixed_mode, NULL, >>> - downclock_mode); >>> + intel_panel_init(&intel_connector->panel, fixed_mode, >>> downclock_mode); >>> intel_panel_setup_backlight(connector, INVALID_PIPE); >>> >>> lvds_encoder->is_dual_link = >>> compute_is_dual_link_lvds(lvds_encoder); >>> diff --git a/drivers/gpu/drm/i915/intel_panel.c >>> b/drivers/gpu/drm/i915/intel_panel.c >>> index 41d00b1603e3..b443278e569c 100644 >>> --- a/drivers/gpu/drm/i915/intel_panel.c >>> +++ b/drivers/gpu/drm/i915/intel_panel.c >>> @@ -1928,13 +1928,11 @@ intel_panel_init_backlight_funcs(struct >>> intel_panel *panel) >>> >>> int intel_panel_init(struct intel_panel *panel, >>> struct drm_display_mode *fixed_mode, >>> - struct drm_display_mode *alt_fixed_mode, >>> struct drm_display_mode *downclock_mode) >>> { >>> intel_panel_init_backlight_funcs(panel); >>> >>> panel->fixed_mode = fixed_mode; >>> - panel->alt_fixed_mode = alt_fixed_mode; >>> panel->downclock_mode = downclock_mode; >>> >>> return 0; >>> @@ -1948,10 +1946,6 @@ void intel_panel_fini(struct intel_panel >>> *panel) >>> if (panel->fixed_mode) >>> drm_mode_destroy(intel_connector->base.dev, panel- >>> >fixed_mode); >>> >>> - if (panel->alt_fixed_mode) >>> - drm_mode_destroy(intel_connector->base.dev, >>> - panel->alt_fixed_mode); >>> - >>> if (panel->downclock_mode) >>> drm_mode_destroy(intel_connector->base.dev, >>> panel->downclock_mode); -- Jani Nikula, Intel Open Source Technology Center
