[Intel-gfx] [PATCH 10/23] drm/i915/dp: Allow big joiner modes in intel_dp_mode_valid()
Maarten Lankhorst
maarten.lankhorst at linux.intel.com
Thu Sep 26 16:00:31 UTC 2019
Op 26-09-2019 om 00:09 schreef Manasi Navare:
> 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 decrease hdisplay_max to 5120 then for < gen12?
intel_mode_valid() currently allows the full mode.
>
>
>> 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
Yeah, I only allow for mode_valid() to succeed with eDP, will fix that with a check.
bigjoiner is not allowed on pipe A through intel_dp_source_supports_dsc, pipe A -> it didn't need an explicit check.
>> 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
>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
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