lkml.org 
[lkml]   [2012]   [Jan]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [Intel-gfx] [PATCH 2/2] drm/i915: Select DP BPC at mode set, rather than mode validate
On Wed, Jan 25, 2012 at 08:16:26AM -0800, Keith Packard wrote:
> The DP configuration must match the pipe configuration, and until mode
> set we don't know what BPC will be used. Delay all decisions about BPC
> until mode set, computing the target BPC in both intel_dp_mode_fixup
> and either i9xx_crtc_mode_set or ironlake_crtc_mode_set. It might be
> slightly better to compute this only once, but storing the value
> between those two calls would be a pain.
>
> Cc: Lubos Kolouch <lubos.kolouch@gmail.com>
> Cc: Adam Jackson <ajax@redhat.com>
> Signed-off-by: Keith Packard <keithp@keithp.com>
> ---
> drivers/gpu/drm/i915/intel_display.c | 27 +++++-------
> drivers/gpu/drm/i915/intel_dp.c | 77 +++++++++++++++++++++++++++-------
> drivers/gpu/drm/i915/intel_drv.h | 6 ++-
> 3 files changed, 78 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index b3b51c4..d613676 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4850,9 +4850,9 @@ static inline bool intel_panel_use_ssc(struct drm_i915_private *dev_priv)
> * 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_display_mode *mode)
> +bool intel_choose_pipe_bpp_dither(struct drm_crtc *crtc,
> + unsigned int *pipe_bpp,
> + struct drm_display_mode *mode)
> {
> struct drm_device *dev = crtc->dev;
> struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -4883,13 +4883,13 @@ static bool intel_choose_pipe_bpp_dither(struct drm_crtc *crtc,
> 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 (intel_encoder->type == INTEL_OUTPUT_EDP ||
> + intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT) {
> + unsigned int dp_bpc = intel_dp_max_bpp(&intel_encoder->base, mode);
>
> - if (edp_bpc < display_bpc) {
> - DRM_DEBUG_KMS("clamping display bpc (was %d) to eDP (%d)\n", display_bpc, edp_bpc);
> - display_bpc = edp_bpc;
> + if (dp_bpc < display_bpc) {
> + DRM_DEBUG_KMS("clamping display bpc (was %d) to DP (%d)\n", display_bpc, dp_bpc);
> + display_bpc = dp_bpc;
> }
> continue;
> }

I'm a bit unhappy how generic code in intel_display.c calls function out
of intel_dp.c. And choose_pipe_bpp_dither already has special cases for
quite a few other encoders ... Could we add an ->adjust_bpc function to
intel_encoder to separate this in a cleaner fashion?

I know that this isn't really the only layering violation in
intel_display.c, but functions in that file have an uncanny ability to
grow without bounds ;-)

> @@ -4923,11 +4923,6 @@ static bool intel_choose_pipe_bpp_dither(struct drm_crtc *crtc,
> }
> }
>
> - if (mode->private_flags & INTEL_MODE_DP_FORCE_6BPC) {
> - DRM_DEBUG_KMS("Dithering DP to 6bpc\n");
> - display_bpc = 6;
> - }
> -
> /*
> * We could just drive the pipe at the highest bpc all the time and
> * enable dithering as needed, but that costs bandwidth. So choose
> @@ -4990,6 +4985,7 @@ static int i9xx_crtc_mode_set(struct drm_crtc *crtc,
> int ret;
> u32 temp;
> u32 lvds_sync = 0;
> + int dp_max_bpp = 0;
>
> list_for_each_entry(encoder, &mode_config->encoder_list, base.head) {
> if (encoder->base.crtc != crtc)
> @@ -5016,6 +5012,7 @@ static int i9xx_crtc_mode_set(struct drm_crtc *crtc,
> break;
> case INTEL_OUTPUT_DISPLAYPORT:
> is_dp = true;
> + dp_max_bpp = intel_dp_max_bpp(&encoder->base, mode);
> break;
> }
>
> @@ -5192,7 +5189,7 @@ static int i9xx_crtc_mode_set(struct drm_crtc *crtc,
> /* default to 8bpc */
> pipeconf &= ~(PIPECONF_BPP_MASK | PIPECONF_DITHER_EN);
> if (is_dp) {
> - if (mode->private_flags & INTEL_MODE_DP_FORCE_6BPC) {
> + if (dp_max_bpp <= 18) {
> pipeconf |= PIPECONF_BPP_6 |
> PIPECONF_DITHER_EN |
> PIPECONF_DITHER_TYPE_SP;
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 94f860c..2482796 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -219,14 +219,51 @@ intel_dp_max_data_rate(int max_link_clock, int max_lanes)
> return (max_link_clock * max_lanes * 8) / 10;
> }
>
> +/*
> + * For the specified encoder, return the maximum bpp that can be used
> + * for the specified mode.
> + */
> +
> +static const int dp_supported_bpc[] = { 6, 8, 10, 12, 16 };
> +
> +#define NUM_DP_SUPPORTED_BPC (sizeof dp_supported_bpc/sizeof dp_supported_bpc[0])
> +
> +int
> +intel_dp_max_bpp(struct drm_encoder *encoder, struct drm_display_mode *mode)
> +{
> + struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> + int max_link_clock = intel_dp_link_clock(intel_dp_max_link_bw(intel_dp));
> + int max_lanes = intel_dp_max_lane_count(intel_dp);
> + int max_rate, mode_rate;
> + int i;
> +
> + max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes);
> + for (i = NUM_DP_SUPPORTED_BPC - 1; i >= 0; i--) {
> + int bpp = dp_supported_bpc[i] * 3; /* 3 channels of data (RGB) */
> +
> + mode_rate = intel_dp_link_required(mode->clock, bpp);
> + if (mode_rate <= max_rate) {
> +
> + /* Limit EDP bpp to panel ability */
> + if (intel_dp->base.type == INTEL_OUTPUT_EDP) {
> + struct drm_device *dev = encoder->dev;
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + int edp_bpp = dev_priv->edp.bpp;
> +
> + if (bpp > edp_bpp)
> + bpp = edp_bpp;
> + }
> + return bpp;
> + }
> + }
> + return 0;
> +}
> +
> static int
> intel_dp_mode_valid(struct drm_connector *connector,
> struct drm_display_mode *mode)
> {
> struct intel_dp *intel_dp = intel_attached_dp(connector);
> - int max_link_clock = intel_dp_link_clock(intel_dp_max_link_bw(intel_dp));
> - int max_lanes = intel_dp_max_lane_count(intel_dp);
> - int max_rate, mode_rate;
>
> if (is_edp(intel_dp) && intel_dp->panel_fixed_mode) {
> if (mode->hdisplay > intel_dp->panel_fixed_mode->hdisplay)
> @@ -236,16 +273,8 @@ intel_dp_mode_valid(struct drm_connector *connector,
> return MODE_PANEL;
> }
>
> - mode_rate = intel_dp_link_required(mode->clock, 24);
> - max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes);
> -
> - if (mode_rate > max_rate) {
> - mode_rate = intel_dp_link_required(mode->clock, 18);
> - if (mode_rate > max_rate)
> - return MODE_CLOCK_HIGH;
> - else
> - mode->private_flags |= INTEL_MODE_DP_FORCE_6BPC;
> - }
> + if (intel_dp_max_bpp(&intel_dp->base.base, mode) == 0)
> + return MODE_CLOCK_HIGH;
>
> if (mode->clock < 10000)
> return MODE_CLOCK_LOW;
> @@ -673,9 +702,26 @@ intel_dp_mode_fixup(struct drm_encoder *encoder, struct drm_display_mode *mode,
> int lane_count, clock;
> int max_lane_count = intel_dp_max_lane_count(intel_dp);
> int max_clock = intel_dp_max_link_bw(intel_dp) == DP_LINK_BW_2_7 ? 1 : 0;
> - int bpp = mode->private_flags & INTEL_MODE_DP_FORCE_6BPC ? 18 : 24;
> + unsigned int bpp;
> static int bws[2] = { DP_LINK_BW_1_62, DP_LINK_BW_2_7 };
>
> + if (HAS_PCH_SPLIT(dev))
> + (void) intel_choose_pipe_bpp_dither(intel_dp->base.base.crtc, &bpp, mode);
> + else {
> + bpp = intel_dp_max_bpp(encoder, mode);
> + if (bpp > 24)
> + bpp = 24;
> + }

As you've already said in another mail, this PCH_SPLIT here looks a bit
strange. Could we unify these two paths here a bit?

Otherwise I couldn't poke holes into it.
-Daniel

> +
> + DRM_DEBUG_KMS("encoder assuming bpp %d (bpc %d)\n",
> + bpp, bpp / 3);
> +
> + if (bpp == 0) {
> + DRM_DEBUG_KMS("Display port cannot support requested clock %d\n",
> + mode->clock);
> + return false;
> + }
> +
> if (is_edp(intel_dp) && intel_dp->panel_fixed_mode) {
> intel_fixed_panel_mode(intel_dp->panel_fixed_mode, adjusted_mode);
> intel_pch_panel_fitting(dev, DRM_MODE_SCALE_FULLSCREEN,
> @@ -691,8 +737,7 @@ intel_dp_mode_fixup(struct drm_encoder *encoder, struct drm_display_mode *mode,
> for (clock = 0; clock <= max_clock; clock++) {
> int link_avail = intel_dp_max_data_rate(intel_dp_link_clock(bws[clock]), lane_count);
>
> - if (intel_dp_link_required(mode->clock, bpp)
> - <= link_avail) {
> + if (intel_dp_link_required(mode->clock, bpp) <= link_avail) {
> intel_dp->link_bw = bws[clock];
> intel_dp->lane_count = lane_count;
> adjusted_mode->clock = intel_dp_link_clock(intel_dp->link_bw);
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 1348705..03b4595 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -104,7 +104,6 @@
> /* drm_display_mode->private_flags */
> #define INTEL_MODE_PIXEL_MULTIPLIER_SHIFT (0x0)
> #define INTEL_MODE_PIXEL_MULTIPLIER_MASK (0xf << INTEL_MODE_PIXEL_MULTIPLIER_SHIFT)
> -#define INTEL_MODE_DP_FORCE_6BPC (0x10)
>
> static inline void
> intel_mode_set_pixel_multiplier(struct drm_display_mode *mode,
> @@ -303,11 +302,16 @@ extern void intel_dp_init(struct drm_device *dev, int dp_reg);
> void
> intel_dp_set_m_n(struct drm_crtc *crtc, struct drm_display_mode *mode,
> struct drm_display_mode *adjusted_mode);
> +extern int intel_dp_max_bpp(struct drm_encoder *encoder, struct drm_display_mode *mode);
> extern bool intel_dpd_is_edp(struct drm_device *dev);
> extern void intel_edp_link_config(struct intel_encoder *, int *, int *);
> extern bool intel_encoder_is_pch_edp(struct drm_encoder *encoder);
> extern int intel_plane_init(struct drm_device *dev, enum pipe pipe);
>
> +bool intel_choose_pipe_bpp_dither(struct drm_crtc *crtc,
> + unsigned int *pipe_bpp,
> + struct drm_display_mode *mode);
> +
> /* intel_panel.c */
> extern void intel_fixed_panel_mode(struct drm_display_mode *fixed_mode,
> struct drm_display_mode *adjusted_mode);
> --
> 1.7.8.3
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

--
Daniel Vetter
Mail: daniel@ffwll.ch
Mobile: +41 (0)79 365 57 48


\
 
 \ /
  Last update: 2012-01-25 23:13    [W:0.109 / U:2.780 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site