[Intel-gfx] [PATCH 10/23] drm/i915/dp: Allow big joiner modes in intel_dp_mode_valid()
Manasi Navare
manasi.d.navare at intel.com
Wed Sep 25 22:09:35 UTC 2019
On Tue, Sep 24, 2019 at 10:30:39PM -0700, Matt Roper wrote:
> On Fri, Sep 20, 2019 at 01:42:22PM +0200, Maarten Lankhorst wrote:
> > Small changes to intel_dp_mode_valid(), allow listing modes that
> > can only be supported in the bigjoiner configuration, which is
> > not supported yet.
> >
> > Also unexport a few functions only used internally in intel_dp.c
> >
> > Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > ---
> > drivers/gpu/drm/i915/display/intel_dp.c | 98 +++++++++++++++++++------
> > 1 file changed, 75 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 2fceb71f7f70..046e1662d1e3 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -247,7 +247,7 @@ intel_dp_max_data_rate(int max_link_clock, int max_lanes)
> > }
> >
> > static int
> > -intel_dp_downstream_max_dotclock(struct intel_dp *intel_dp)
> > +intel_dp_downstream_max_dotclock(struct intel_dp *intel_dp, bool allow_bigjoiner)
> > {
> > struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
> > struct intel_encoder *encoder = &intel_dig_port->base;
> > @@ -257,6 +257,9 @@ intel_dp_downstream_max_dotclock(struct intel_dp *intel_dp)
> >
> > int type = intel_dp->downstream_ports[0] & DP_DS_PORT_TYPE_MASK;
> >
> > + if (allow_bigjoiner && INTEL_GEN(dev_priv) >= 11)
> > + max_dotclk *= 2;
> > +
Since here we allow the big joiner for >=11 (ICL+), we need to update the
plane_mode_valid check to ensure that we allow the 8K mode only for TGL+
else with big joiner enabled on ICL we will enable it on ICL which is not permitted (not POR)
>
> Should we be checking if the specific pipe can do big joiner on the
> platform (gen11 vs gen12 differences) and also omitting eDP from
> consideration?
>
>
> > if (type != DP_DS_PORT_TYPE_VGA)
> > return max_dotclk;
> >
> > @@ -505,8 +508,10 @@ u32 intel_dp_fec_to_mode_clock(u32 fec_clock)
> > 1000000U);
> > }
> >
> > -static u16 intel_dp_dsc_get_output_bpp(u32 link_clock, u32 lane_count,
> > - u32 mode_clock, u32 mode_hdisplay)
> > +static u16 intel_dp_dsc_get_output_bpp(struct drm_i915_private *dev_priv,
> > + u32 link_clock, u32 lane_count,
> > + u32 mode_clock, u32 mode_hdisplay,
> > + bool bigjoiner)
> > {
> > u32 bits_per_pixel, max_bpp_small_joiner_ram;
> > int i;
> > @@ -523,6 +528,10 @@ static u16 intel_dp_dsc_get_output_bpp(u32 link_clock, u32 lane_count,
> >
> > /* Small Joiner Check: output bpp <= joiner RAM (bits) / Horiz. width */
> > max_bpp_small_joiner_ram = DP_DSC_MAX_SMALL_JOINER_RAM_BUFFER / mode_hdisplay;
> > +
> > + if (bigjoiner)
> > + max_bpp_small_joiner_ram *= 2;
> > +
>
> This change is correct, but while confirming in the bspec I noticed that
> we may have the wrong DP_DSC_MAX_SMALL_JOINER_RAM_BUFFER value for
> gen11+. It indicates 6144 for GLK, CNL, but 7680 for ICL+ (and double
> that to 15360 when using big joiner).
>
> Bspec: 20388
> Bspec: 49259
@Matt, the 7680 is in bytes which translates to 61440 bits and thats what
we are using, see the #DP_DSC_MAX_SMALL_JOINER_RAM_BUFFER
and then its double for big joiner, so this is correct
>
> > DRM_DEBUG_KMS("Max small joiner bpp: %u\n", max_bpp_small_joiner_ram);
> >
> > /*
> > @@ -531,6 +540,15 @@ static u16 intel_dp_dsc_get_output_bpp(u32 link_clock, u32 lane_count,
> > */
> > bits_per_pixel = min(bits_per_pixel, max_bpp_small_joiner_ram);
> >
> > + if (bigjoiner) {
> > + u32 max_bpp_bigjoiner =
> > + dev_priv->max_cdclk_freq * 48 /
> > + intel_dp_mode_to_fec_clock(mode_clock);
>
> Minor nitpick, but just to match the bspec (PPC * CDCLK * 24 bits /
> pixel clock), I'd keep the 2 PPC and 24 bit factors separate here.
>
Yes I agree her with Matt that we shd keep the 2ppc separate just to match bspec
> > +
> > + DRM_DEBUG_KMS("Max big joiner bpp: %u\n", max_bpp_bigjoiner);
> > + bits_per_pixel = min(bits_per_pixel, max_bpp_bigjoiner);
> > + }
> > +
> > /* Error out if the max bpp is less than smallest allowed valid bpp */
> > if (bits_per_pixel < valid_dsc_bpp[0]) {
> > DRM_DEBUG_KMS("Unsupported BPP %u, min %u\n",
> > @@ -553,7 +571,8 @@ static u16 intel_dp_dsc_get_output_bpp(u32 link_clock, u32 lane_count,
> > }
> >
> > static u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp,
> > - int mode_clock, int mode_hdisplay)
> > + int mode_clock, int mode_hdisplay,
> > + bool bigjoiner)
> > {
> > u8 min_slice_count, i;
> > int max_slice_width;
> > @@ -578,12 +597,20 @@ static u8 intel_dp_dsc_get_slice_count(struct intel_dp *intel_dp,
> >
> > /* Find the closest match to the valid slice count values */
> > for (i = 0; i < ARRAY_SIZE(valid_dsc_slicecount); i++) {
> > - if (valid_dsc_slicecount[i] >
> > - drm_dp_dsc_sink_max_slice_count(intel_dp->dsc_dpcd,
> > - false))
> > + u8 test_slice_count = bigjoiner ?
> > + 2 * valid_dsc_slicecount[i] :
> > + valid_dsc_slicecount[i];
> > +
> > + if (test_slice_count >
> > + drm_dp_dsc_sink_max_slice_count(intel_dp->dsc_dpcd, false))
> > break;
> > - if (min_slice_count <= valid_dsc_slicecount[i])
> > - return valid_dsc_slicecount[i];
> > +
> > + /* big joiner needs small joiner to be enabled */
> > + if (bigjoiner && test_slice_count < 4)
> > + continue;
> > +
> > + if (min_slice_count <= test_slice_count)
> > + return test_slice_count;
> > }
> >
> > DRM_DEBUG_KMS("Unsupported Slice Count %d\n", min_slice_count);
> > @@ -603,11 +630,15 @@ intel_dp_mode_valid(struct drm_connector *connector,
> > int max_dotclk;
> > u16 dsc_max_output_bpp = 0;
> > u8 dsc_slice_count = 0;
> > + bool dsc = false, bigjoiner = false;
> >
> > if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
> > return MODE_NO_DBLESCAN;
> >
> > - max_dotclk = intel_dp_downstream_max_dotclock(intel_dp);
> > + if (mode->flags & DRM_MODE_FLAG_DBLCLK)
> > + return MODE_H_ILLEGAL;
> > +
> > + max_dotclk = intel_dp_downstream_max_dotclock(intel_dp, false);
> >
> > if (intel_dp_is_edp(intel_dp) && fixed_mode) {
> > if (mode->hdisplay > fixed_mode->hdisplay)
> > @@ -619,6 +650,18 @@ intel_dp_mode_valid(struct drm_connector *connector,
> > target_clock = fixed_mode->clock;
> > }
> >
> > + if (mode->clock < 10000)
> > + return MODE_CLOCK_LOW;
> > +
> > + if (target_clock > max_dotclk) {
> > + max_dotclk = intel_dp_downstream_max_dotclock(intel_dp, true);
> > +
> > + if (target_clock > max_dotclk)
> > + return MODE_CLOCK_HIGH;
> > +
> > + bigjoiner = true;
> > + }
> > +
> > max_link_clock = intel_dp_max_link_rate(intel_dp);
> > max_lanes = intel_dp_max_lane_count(intel_dp);
> >
> > @@ -639,26 +682,32 @@ intel_dp_mode_valid(struct drm_connector *connector,
> > true);
> > } else if (drm_dp_sink_supports_fec(intel_dp->fec_capable)) {
> > dsc_max_output_bpp =
> > - intel_dp_dsc_get_output_bpp(max_link_clock,
> > + intel_dp_dsc_get_output_bpp(dev_priv,
> > + max_link_clock,
> > max_lanes,
> > target_clock,
> > - mode->hdisplay) >> 4;
> > + mode->hdisplay,
> > + bigjoiner) >> 4;
> > dsc_slice_count =
> > intel_dp_dsc_get_slice_count(intel_dp,
> > target_clock,
> > - mode->hdisplay);
> > + mode->hdisplay,
> > + bigjoiner);
> > }
> > +
> > + dsc = dsc_max_output_bpp && dsc_slice_count;
> > }
> >
> > - if ((mode_rate > max_rate && !(dsc_max_output_bpp && dsc_slice_count)) ||
> > - target_clock > max_dotclk)
> > + /* big joiner configuration needs DSC */
> > + if (bigjoiner && !dsc) {
> > + DRM_DEBUG_KMS("Link clock needs bigjoiner, but DSC or FEC not available\n");
> > return MODE_CLOCK_HIGH;
> > + }
>
> Somewhere in this function we probably also need to make sure that the
> big joiner is available on the pipe and that we're not using eDP.
>
Yes I agree we need to check that we allow big joine only for B and C for ICL and then
all pipes for TGL+ and not allow for eDP
Manasi
>
> Matt
>
> >
> > - if (mode->clock < 10000)
> > - return MODE_CLOCK_LOW;
> > -
> > - if (mode->flags & DRM_MODE_FLAG_DBLCLK)
> > - return MODE_H_ILLEGAL;
> > + if (mode_rate > max_rate && !dsc) {
> > + DRM_DEBUG_KMS("Cannot drive without DSC\n");
> > + return MODE_CLOCK_HIGH;
> > + }
> >
> > return intel_mode_valid_max_plane_size(dev_priv, mode);
> > }
> > @@ -2068,14 +2117,17 @@ static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
> > u8 dsc_dp_slice_count;
> >
> > dsc_max_output_bpp =
> > - intel_dp_dsc_get_output_bpp(pipe_config->port_clock,
> > + intel_dp_dsc_get_output_bpp(dev_priv,
> > + pipe_config->port_clock,
> > pipe_config->lane_count,
> > adjusted_mode->crtc_clock,
> > - adjusted_mode->crtc_hdisplay);
> > + adjusted_mode->crtc_hdisplay,
> > + false);
> > dsc_dp_slice_count =
> > intel_dp_dsc_get_slice_count(intel_dp,
> > adjusted_mode->crtc_clock,
> > - adjusted_mode->crtc_hdisplay);
> > + adjusted_mode->crtc_hdisplay,
> > + false);
> > if (!dsc_max_output_bpp || !dsc_dp_slice_count) {
> > DRM_DEBUG_KMS("Compressed BPP/Slice Count not supported\n");
> > return -EINVAL;
> > --
> > 2.20.1
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Matt Roper
> Graphics Software Engineer
> VTT-OSGC Platform Enablement
> Intel Corporation
> (916) 356-2795
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
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