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-rw-r--r--drivers/gpu/drm/i915/intel_display.c194
-rw-r--r--drivers/gpu/drm/i915/intel_drv.h1
2 files changed, 153 insertions, 42 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index ce3666d53f57..7c5d28fd5f36 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 8ac3bd8b6faa..7ec48d864577 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)
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-15 09:33:37 +0000