From mboxrd@z Thu Jan 1 00:00:00 1970 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 5BBF1CF6497 for ; Mon, 30 Sep 2024 08:02:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E782110E3C0; Mon, 30 Sep 2024 08:02:26 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="E/uMA1VV"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id 26E6910E3C0; Mon, 30 Sep 2024 08:02:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1727683346; x=1759219346; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=F+wvVLejjLbClhrDWaZbyontWZRu9R2jSyAC1divVsU=; b=E/uMA1VVfwG5F9Rpxq211ZQNi/4sVJ2CuvtTv6k8G0vGAsoHombBuwxF yagHgKM4PnrWCbVf8+IPbP3l44I2zsHtTD0VbkYBerOfwLatjYvTwZaa7 1254LFNDfoqbQjv4FXbGlKSv4TMtZE3lUJwpHVwn/7dDISjobLQx3WRtg Yjk7UDNboLvE/Lx6aLLdQT4CLzkKnodrF/vSTqxNHnqGL9mPxHMRIQv0y QxRbcjGGRzQxLO5zArIuEYNZbfa6xsizDXJ+wc+5CP+fjfKLwd/oBRWZu mrWzBkskBawluk6zDqbopeuuLT6QzHw21g5FLd0sziaKFue6TxMJ+48y4 Q==; X-CSE-ConnectionGUID: tz4i5RPxS0CER2QRbPt6ww== X-CSE-MsgGUID: zxNtdu1ASSGR5ZydfspVzQ== X-IronPort-AV: E=McAfee;i="6700,10204,11210"; a="37318150" X-IronPort-AV: E=Sophos;i="6.11,165,1725346800"; d="scan'208";a="37318150" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by orvoesa103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Sep 2024 01:01:31 -0700 X-CSE-ConnectionGUID: B+wkQQ3WTxOdr5WC8DIb9g== X-CSE-MsgGUID: HY5Q1k5nTL2hPKQ4+bKXZw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.11,165,1725346800"; d="scan'208";a="73619565" Received: from mklonows-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.246.93]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Sep 2024 01:01:29 -0700 From: Jani Nikula To: Arun R Murthy , intel-xe@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: Arun R Murthy Subject: Re: [PATCH] drm/i915/dp: Guarantee a minimum HBlank time In-Reply-To: <20240930055416.2112473-1-arun.r.murthy@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20240930055416.2112473-1-arun.r.murthy@intel.com> Date: Mon, 30 Sep 2024 11:01:16 +0300 Message-ID: <8734lhy3hv.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Mon, 30 Sep 2024, Arun R Murthy wrote: > Mandate a minimum Hblank symbol cycle count between BS and BE in 8b/10b > MST and 12b/132b mode. > Spec: DP2.1a Why send patches on top of a baseline that's 20 days old? Please rebase and build before sending. Always. > Signed-off-by: Arun R Murthy > --- > drivers/gpu/drm/i915/display/intel_display.c | 6 ++++++ > drivers/gpu/drm/i915/display/intel_display_types.h | 1 + > drivers/gpu/drm/i915/display/intel_dp_mst.c | 9 +++++++++ > drivers/gpu/drm/i915/i915_reg.h | 3 +++ > 4 files changed, 19 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c > index 78ce402a5cd0..027ab45d4d38 100644 > --- a/drivers/gpu/drm/i915/display/intel_display.c > +++ b/drivers/gpu/drm/i915/display/intel_display.c > @@ -2095,6 +2095,7 @@ void intel_modeset_put_crtc_power_domains(struct intel_crtc *crtc, > static void i9xx_configure_cpu_transcoder(const struct intel_crtc_state *crtc_state) > { > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); > + struct drm_i915_private *i915 = to_i915(crtc->base.dev); struct intel_display. > enum transcoder cpu_transcoder = crtc_state->cpu_transcoder; > > if (intel_crtc_has_dp_encoder(crtc_state)) { > @@ -2102,6 +2103,11 @@ static void i9xx_configure_cpu_transcoder(const struct intel_crtc_state *crtc_st > &crtc_state->dp_m_n); > intel_cpu_transcoder_set_m2_n2(crtc, cpu_transcoder, > &crtc_state->dp_m2_n2); > + > + if (DISPLAY_VER(i915) >= 20 && crtc_state->dp_m_n.min_hblank) > + intel_de_write(i915, > + DP_MIN_HBLANK_CTL(i915, cpu_transcoder), > + crtc_state->dp_m_n.min_hblank); Doesn't feel right programming this here. Doesn't feel right having DP checks here. Where is this cleared? The state readout and verification is missing. > } > > intel_set_transcoder_timings(crtc_state); > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > index fa03157554b2..8d18545a369f 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > @@ -1028,6 +1028,7 @@ struct intel_link_m_n { > u32 data_n; > u32 link_m; > u32 link_n; > + u32 min_hblank; Doesn't feel right adding this here, not much to do with M/N. > }; > > struct intel_csc_matrix { > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c > index 15541932b809..c8f045142881 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c > @@ -130,6 +130,8 @@ static void intel_dp_mst_compute_m_n(const struct intel_crtc_state *crtc_state, > { > const struct drm_display_mode *adjusted_mode = > &crtc_state->hw.adjusted_mode; > + u8 symbol_size = intel_dp_is_uhbr(crtc_state) ? 32 : 8; Just use int. > + u32 hblank; > > /* TODO: Check WA 14013163432 to set data M/N for full BW utilization. */ > intel_link_compute_m_n(bpp_x16, crtc_state->lane_count, > @@ -139,6 +141,13 @@ static void intel_dp_mst_compute_m_n(const struct intel_crtc_state *crtc_state, > m_n); > > m_n->tu = DIV_ROUND_UP_ULL(mul_u32_u32(m_n->data_m, 64), m_n->data_n); > + > + /* Calculate min Hblank Link Layer Symbol Cycle Count for 8b/10b MST & 128b/132b */ > + hblank = DIV_ROUND_UP((DIV_ROUND_UP(adjusted_mode->htotal - adjusted_mode->hdisplay, 4) * bpp_x16), symbol_size); > + if (intel_dp_is_uhbr(crtc_state)) > + m_n->min_hblank = hblank > 5 ? hblank : 5; > + else > + m_n->min_hblank = hblank > 3 ? hblank : 3; > } > > static int intel_dp_mst_calc_pbn(int pixel_clock, int bpp_x16, int bw_overhead) > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h > index 41f4350a7c6c..65133efe728c 100644 > --- a/drivers/gpu/drm/i915/i915_reg.h > +++ b/drivers/gpu/drm/i915/i915_reg.h > @@ -1109,6 +1109,7 @@ > #define _BCLRPAT_A 0x60020 > #define _TRANS_VSYNCSHIFT_A 0x60028 > #define _TRANS_MULT_A 0x6002c > +#define _DP_MIN_HBLANK_CTL_A 0x600ac > > /* Pipe/transcoder B timing regs */ > #define _TRANS_HTOTAL_B 0x61000 > @@ -1121,6 +1122,7 @@ > #define _BCLRPAT_B 0x61020 > #define _TRANS_VSYNCSHIFT_B 0x61028 > #define _TRANS_MULT_B 0x6102c > +#define _DP_MIN_HBLANK_CTL_B 0x610ac > > /* DSI 0 timing regs */ > #define _TRANS_HTOTAL_DSI0 0x6b000 > @@ -1146,6 +1148,7 @@ > #define TRANS_VSYNCSHIFT(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _TRANS_VSYNCSHIFT_A) > #define PIPESRC(dev_priv, pipe) _MMIO_TRANS2(dev_priv, (pipe), _PIPEASRC) > #define TRANS_MULT(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _TRANS_MULT_A) > +#define DP_MIN_HBLANK_CTL(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _DP_MIN_HBLANK_CTL_A) > > /* VGA port control */ > #define ADPA _MMIO(0x61100) -- Jani Nikula, Intel