From patchwork Thu Aug 24 08:05:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Imre Deak X-Patchwork-Id: 13363740 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 50192C27C40 for ; Thu, 24 Aug 2023 08:05:41 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D519310E4F6; Thu, 24 Aug 2023 08:05:28 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0165310E4C9; Thu, 24 Aug 2023 08:05:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1692864316; x=1724400316; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=DzUzAkotMdYaaDH+bpfMfQn1lE9QvOXz/KEc/cGaam8=; b=KjEGscZDXGoLG0SKFpPZwacbZ+O6sUGV/p0R1e5m4mo+k1YGJRlAFqBC w0Ylmzx2IpFaqGKuYo0/Y4jKA8ZtadhYSAvlvXoFRIMyIyfwkOy9DcMKu da2sIBtyfm6Ug4kO/9B7GytQ61BUEXP7aF1PZKSxtKsawR7W9ei6HcTLI OCd62iD3ip6+t6k8QrQ9R1rnspvt2sHm9IepncNq/008c4aAEaV1p57y5 Y3POMCK9rYdXQIGsO9RvxcDVXJ3dsvI9eJfHi3bCTEOKIvHdQ1UTBmfHh JgKJTPgBOBsmfiKTnj9BKeiCMFdkD4r95wX5Z1i3HwZHKocewr299nszt Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10811"; a="374345871" X-IronPort-AV: E=Sophos;i="6.01,195,1684825200"; d="scan'208";a="374345871" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2023 01:05:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.01,202,1684825200"; d="scan'208";a="880710320" Received: from ideak-desk.fi.intel.com ([10.237.72.78]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Aug 2023 01:05:18 -0700 From: Imre Deak To: intel-gfx@lists.freedesktop.org Date: Thu, 24 Aug 2023 11:05:05 +0300 Message-Id: <20230824080517.693621-11-imre.deak@intel.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20230824080517.693621-1-imre.deak@intel.com> References: <20230824080517.693621-1-imre.deak@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v2 10/22] drm/dp_mst: Add a way to calculate PBN values with FEC overhead X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alex Deucher , Harry Wentland , dri-devel@lists.freedesktop.org, Wayne Lin Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Add a way for drivers to calculate the MST PBN values with FEC overhead. This is required by 8b/10b links both for DSC and non-DSC (the latter needed if there are both DSC and non-DSC streams on the same MST link). Also add kunit test cases for PBN values calculated with FEC overhead. Cc: Lyude Paul Cc: Harry Wentland Cc: Wayne Lin Cc: Alex Deucher Cc: dri-devel@lists.freedesktop.org Signed-off-by: Imre Deak --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +- .../display/amdgpu_dm/amdgpu_dm_mst_types.c | 2 +- drivers/gpu/drm/display/drm_dp_mst_topology.c | 18 +++++++++++---- drivers/gpu/drm/i915/display/intel_dp_mst.c | 5 ++-- drivers/gpu/drm/nouveau/dispnv50/disp.c | 2 +- .../gpu/drm/tests/drm_dp_mst_helper_test.c | 23 ++++++++++++++++++- include/drm/display/drm_dp_mst_helper.h | 2 +- 7 files changed, 42 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 268cb99a4c4bc..22868d6eb8977 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -6782,7 +6782,7 @@ static int dm_encoder_helper_atomic_check(struct drm_encoder *encoder, max_bpc); bpp = convert_dc_color_depth_into_bpc(color_depth) * 3; clock = adjusted_mode->clock; - dm_new_connector_state->pbn = drm_dp_calc_pbn_mode(clock, bpp, false); + dm_new_connector_state->pbn = drm_dp_calc_pbn_mode(clock, bpp, false, false); } dm_new_connector_state->vcpi_slots = diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index 57230661132bd..9acfdefc792d6 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -1636,7 +1636,7 @@ enum dc_status dm_dp_mst_is_port_support_mode( } else { /* check if mode could be supported within full_pbn */ bpp = convert_dc_color_depth_into_bpc(stream->timing.display_color_depth) * 3; - pbn = drm_dp_calc_pbn_mode(stream->timing.pix_clk_100hz / 10, bpp, false); + pbn = drm_dp_calc_pbn_mode(stream->timing.pix_clk_100hz / 10, bpp, false, false); if (pbn > aconnector->mst_output_port->full_pbn) return DC_FAIL_BANDWIDTH_VALIDATE; diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index bd0f35a0ea5fb..e26f1b7f5a701 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -4693,26 +4693,34 @@ EXPORT_SYMBOL(drm_dp_check_act_status); * @clock: dot clock for the mode * @bpp: bpp for the mode. * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel + * @fec: FEC overhead. * * This uses the formula in the spec to calculate the PBN value for a mode. */ -int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc) +int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc, bool fec) { /* - * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 + * Overheads: + * - SSC downspread and ref clock variation margin: + * 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 + * - FEC symbol insertions: + * 2.4% as per spec, factor is 1.024 + * * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on * common multiplier to render an integer PBN for all link rate/lane * counts combinations * calculate - * peak_kbps *= (1006/1000) + * peak_kbps *= (1006/1000) without FEC, or + * peak_kbps *= (1030/1000) with FEC * peak_kbps *= (64/54) - * peak_kbps *= 8 convert to bytes + * peak_kbps /= 8 convert to bytes * * If the bpp is in units of 1/16, further divide by 16. Put this * factor in the numerator rather than the denominator to avoid * integer overflow */ - u32 bpp_m = (dsc ? 64 / 16 : 64) * 1006 * bpp; + u32 overhead = fec ? 1030 : 1006; + u32 bpp_m = (dsc ? 64 / 16 : 64) * overhead * bpp; return DIV_ROUND_UP_ULL(mul_u32_u32(clock, bpp_m), 8 * 54 * 1000 * 1000); diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 525766206fce5..6eeb7dbf5ba67 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -110,7 +110,8 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, crtc_state->pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock, dsc ? bpp << 4 : bpp, - dsc); + dsc, + false); slots = drm_dp_atomic_find_time_slots(state, &intel_dp->mst_mgr, connector->port, @@ -983,7 +984,7 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector, return ret; if (mode_rate > max_rate || mode->clock > max_dotclk || - drm_dp_calc_pbn_mode(mode->clock, min_bpp, false) > port->full_pbn) { + drm_dp_calc_pbn_mode(mode->clock, min_bpp, false, false) > port->full_pbn) { *status = MODE_CLOCK_HIGH; return 0; } diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c index 4e7c9c353c511..d71c28e458107 100644 --- a/drivers/gpu/drm/nouveau/dispnv50/disp.c +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c @@ -967,7 +967,7 @@ nv50_msto_atomic_check(struct drm_encoder *encoder, asyh->or.bpc = connector->display_info.bpc; asyh->dp.pbn = drm_dp_calc_pbn_mode(clock, asyh->or.bpc * 3, - false); + false, false); } mst_state = drm_atomic_get_mst_topology_state(state, &mstm->mgr); diff --git a/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c b/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c index ea2182815ebe8..3c0c0ffd5f9f5 100644 --- a/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c +++ b/drivers/gpu/drm/tests/drm_dp_mst_helper_test.c @@ -16,6 +16,7 @@ struct drm_dp_mst_calc_pbn_mode_test { const int clock; const int bpp; const bool dsc; + const bool fec; const int expected; }; @@ -24,39 +25,59 @@ static const struct drm_dp_mst_calc_pbn_mode_test drm_dp_mst_calc_pbn_mode_cases .clock = 154000, .bpp = 30, .dsc = false, + .fec = false, .expected = 689 }, { .clock = 234000, .bpp = 30, .dsc = false, + .fec = false, .expected = 1047 }, { .clock = 297000, .bpp = 24, .dsc = false, + .fec = false, .expected = 1063 }, { .clock = 332880, .bpp = 24 << 4, .dsc = true, + .fec = false, .expected = 1191 }, { .clock = 324540, .bpp = 24 << 4, .dsc = true, + .fec = false, .expected = 1161 }, + { + .clock = 324540, + .bpp = 24 << 4, + .dsc = true, + .fec = true, + .expected = 1189 + }, + { + .clock = 324540, + .bpp = 24, + .dsc = false, + .fec = true, + .expected = 1189 + }, }; static void drm_test_dp_mst_calc_pbn_mode(struct kunit *test) { const struct drm_dp_mst_calc_pbn_mode_test *params = test->param_value; - KUNIT_EXPECT_EQ(test, drm_dp_calc_pbn_mode(params->clock, params->bpp, params->dsc), + KUNIT_EXPECT_EQ(test, drm_dp_calc_pbn_mode(params->clock, params->bpp, + params->dsc, params->fec), params->expected); } diff --git a/include/drm/display/drm_dp_mst_helper.h b/include/drm/display/drm_dp_mst_helper.h index ed5c9660563c4..0953b7b16a51b 100644 --- a/include/drm/display/drm_dp_mst_helper.h +++ b/include/drm/display/drm_dp_mst_helper.h @@ -832,7 +832,7 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr, int link_rate, int link_lane_count); -int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc); +int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc, bool fec); void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap);