diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index ce3666d53f57d82bc720345de08b2426e9351a25..7c5d28fd5f36a89deaf1d3b067c602e7ec3d0a4b 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -4309,6 +4309,133 @@ static inline bool intel_panel_use_ssc(struct drm_i915_private *dev_priv) return dev_priv->lvds_use_ssc && i915_panel_use_ssc; } +/** + * intel_choose_pipe_bpp_dither - figure out what color depth the pipe should send + * @crtc: CRTC structure + * + * A pipe may be connected to one or more outputs. Based on the depth of the + * attached framebuffer, choose a good color depth to use on the pipe. + * + * If possible, match the pipe depth to the fb depth. In some cases, this + * isn't ideal, because the connected output supports a lesser or restricted + * set of depths. Resolve that here: + * LVDS typically supports only 6bpc, so clamp down in that case + * HDMI supports only 8bpc or 12bpc, so clamp to 8bpc with dither for 10bpc + * Displays may support a restricted set as well, check EDID and clamp as + * appropriate. + * + * RETURNS: + * Dithering requirement (i.e. false if display bpc and pipe bpc match, + * true if they don't match). + */ +static bool intel_choose_pipe_bpp_dither(struct drm_crtc *crtc, + unsigned int *pipe_bpp) +{ + struct drm_device *dev = crtc->dev; + struct drm_i915_private *dev_priv = dev->dev_private; + struct drm_encoder *encoder; + struct drm_connector *connector; + unsigned int display_bpc = UINT_MAX, bpc; + + /* Walk the encoders & connectors on this crtc, get min bpc */ + list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) { + struct intel_encoder *intel_encoder = to_intel_encoder(encoder); + + if (encoder->crtc != crtc) + continue; + + if (intel_encoder->type == INTEL_OUTPUT_LVDS) { + unsigned int lvds_bpc; + + if ((I915_READ(PCH_LVDS) & LVDS_A3_POWER_MASK) == + LVDS_A3_POWER_UP) + lvds_bpc = 8; + else + lvds_bpc = 6; + + if (lvds_bpc < display_bpc) { + DRM_DEBUG_DRIVER("clamping display bpc (was %d) to LVDS (%d)\n", display_bpc, lvds_bpc); + display_bpc = lvds_bpc; + } + continue; + } + + if (intel_encoder->type == INTEL_OUTPUT_EDP) { + /* Use VBT settings if we have an eDP panel */ + unsigned int edp_bpc = dev_priv->edp.bpp / 3; + + if (edp_bpc < display_bpc) { + DRM_DEBUG_DRIVER("clamping display bpc (was %d) to eDP (%d)\n", display_bpc, edp_bpc); + display_bpc = edp_bpc; + } + continue; + } + + /* Not one of the known troublemakers, check the EDID */ + list_for_each_entry(connector, &dev->mode_config.connector_list, + head) { + if (connector->encoder != encoder) + continue; + + if (connector->display_info.bpc < display_bpc) { + DRM_DEBUG_DRIVER("clamping display bpc (was %d) to EDID reported max of %d\n", display_bpc, connector->display_info.bpc); + display_bpc = connector->display_info.bpc; + } + } + + /* + * HDMI is either 12 or 8, so if the display lets 10bpc sneak + * through, clamp it down. (Note: >12bpc will be caught below.) + */ + if (intel_encoder->type == INTEL_OUTPUT_HDMI) { + if (display_bpc > 8 && display_bpc < 12) { + DRM_DEBUG_DRIVER("forcing bpc to 12 for HDMI\n"); + display_bpc = 12; + } else { + DRM_DEBUG_DRIVER("forcing bpc to 8 for HDMI\n"); + display_bpc = 8; + } + } + } + + /* + * We could just drive the pipe at the highest bpc all the time and + * enable dithering as needed, but that costs bandwidth. So choose + * the minimum value that expresses the full color range of the fb but + * also stays within the max display bpc discovered above. + */ + + switch (crtc->fb->depth) { + case 8: + bpc = 8; /* since we go through a colormap */ + break; + case 15: + case 16: + bpc = 6; /* min is 18bpp */ + break; + case 24: + bpc = min((unsigned int)8, display_bpc); + break; + case 30: + bpc = min((unsigned int)10, display_bpc); + break; + case 48: + bpc = min((unsigned int)12, display_bpc); + break; + default: + DRM_DEBUG("unsupported depth, assuming 24 bits\n"); + bpc = min((unsigned int)8, display_bpc); + break; + } + + DRM_DEBUG_DRIVER("setting pipe bpc to %d (max display bpc %d)\n", + bpc, display_bpc); + + *pipe_bpp = bpc * 3; + + return display_bpc != bpc; +} + static int i9xx_crtc_mode_set(struct drm_crtc *crtc, struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode, @@ -4721,7 +4848,9 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc, struct fdi_m_n m_n = {0}; u32 temp; u32 lvds_sync = 0; - int target_clock, pixel_multiplier, lane, link_bw, bpp, factor; + int target_clock, pixel_multiplier, lane, link_bw, factor; + unsigned int pipe_bpp; + bool dither; list_for_each_entry(encoder, &mode_config->encoder_list, base.head) { if (encoder->base.crtc != crtc) @@ -4848,56 +4977,37 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc, /* determine panel color depth */ temp = I915_READ(PIPECONF(pipe)); temp &= ~PIPE_BPC_MASK; - if (is_lvds) { - /* the BPC will be 6 if it is 18-bit LVDS panel */ - if ((I915_READ(PCH_LVDS) & LVDS_A3_POWER_MASK) == LVDS_A3_POWER_UP) - temp |= PIPE_8BPC; - else - temp |= PIPE_6BPC; - } else if (has_edp_encoder) { - switch (dev_priv->edp.bpp/3) { - case 8: - temp |= PIPE_8BPC; - break; - case 10: - temp |= PIPE_10BPC; - break; - case 6: - temp |= PIPE_6BPC; - break; - case 12: - temp |= PIPE_12BPC; - break; - } - } else - temp |= PIPE_8BPC; - I915_WRITE(PIPECONF(pipe), temp); - - switch (temp & PIPE_BPC_MASK) { - case PIPE_8BPC: - bpp = 24; + dither = intel_choose_pipe_bpp_dither(crtc, &pipe_bpp); + switch (pipe_bpp) { + case 18: + temp |= PIPE_6BPC; break; - case PIPE_10BPC: - bpp = 30; + case 24: + temp |= PIPE_8BPC; break; - case PIPE_6BPC: - bpp = 18; + case 30: + temp |= PIPE_10BPC; break; - case PIPE_12BPC: - bpp = 36; + case 36: + temp |= PIPE_12BPC; break; default: - DRM_ERROR("unknown pipe bpc value\n"); - bpp = 24; + WARN(1, "intel_choose_pipe_bpp returned invalid value\n"); + temp |= PIPE_8BPC; + pipe_bpp = 24; + break; } + intel_crtc->bpp = pipe_bpp; + I915_WRITE(PIPECONF(pipe), temp); + if (!lane) { /* * Account for spread spectrum to avoid * oversubscribing the link. Max center spread * is 2.5%; use 5% for safety's sake. */ - u32 bps = target_clock * bpp * 21 / 20; + u32 bps = target_clock * intel_crtc->bpp * 21 / 20; lane = bps / (link_bw * 8) + 1; } @@ -4905,7 +5015,8 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc, if (pixel_multiplier > 1) link_bw *= pixel_multiplier; - ironlake_compute_m_n(bpp, lane, target_clock, link_bw, &m_n); + ironlake_compute_m_n(intel_crtc->bpp, lane, target_clock, link_bw, + &m_n); /* Ironlake: try to setup display ref clock before DPLL * enabling. This is only under driver's control after @@ -5108,14 +5219,12 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc, I915_WRITE(PCH_LVDS, temp); } - /* set the dithering flag and clear for anything other than a panel. */ pipeconf &= ~PIPECONF_DITHER_EN; pipeconf &= ~PIPECONF_DITHER_TYPE_MASK; - if (dev_priv->lvds_dither && (is_lvds || has_edp_encoder)) { + if ((is_lvds && dev_priv->lvds_dither) || dither) { pipeconf |= PIPECONF_DITHER_EN; pipeconf |= PIPECONF_DITHER_TYPE_ST1; } - if (is_dp || intel_encoder_is_pch_edp(&has_edp_encoder->base)) { intel_dp_set_m_n(crtc, mode, adjusted_mode); } else { @@ -6638,6 +6747,7 @@ static void intel_crtc_init(struct drm_device *dev, int pipe) intel_crtc_reset(&intel_crtc->base); intel_crtc->active = true; /* force the pipe off on setup_init_config */ + intel_crtc->bpp = 24; /* default for pre-Ironlake */ if (HAS_PCH_SPLIT(dev)) { intel_helper_funcs.prepare = ironlake_crtc_prepare; diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 8ac3bd8b6faa8a67ac35170d537679903d7ff14e..7ec48d8645771261000afb4a88f2347b3f933025 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -170,6 +170,7 @@ struct intel_crtc { int16_t cursor_x, cursor_y; int16_t cursor_width, cursor_height; bool cursor_visible; + unsigned int bpp; }; #define to_intel_crtc(x) container_of(x, struct intel_crtc, base)