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 9F29EC83F15 for ; Wed, 30 Aug 2023 05:17:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 276C810E4B7; Wed, 30 Aug 2023 05:17:05 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 29DFB10E4B7 for ; Wed, 30 Aug 2023 05:17:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1693372623; x=1724908623; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=CG64WBZ8VOaekxZpbntYWtEKztdqs8aU7neXSLEOZFw=; b=CSsYOElkRCUQkZxJsf90+RWUPyQmWu30kN1YSHVbKVwx82BOBgKky9of 4bFO3NPYtRhp0ognz7BwEFnVP/41OtD15+cMlhK/Hh/F8vwtfH/R3aVjb PN2IF79JGv8B/UiNdhzM5775ffNsTDKmMHf6iPC3aizuHWJZW5K1dWNhl i4lN0hCE4nVIdGh9ksn91gg+SuyNl8+3rl3Uka6EID1eE0stpjg3euNPv mNasC5ZM7JJIWfmyLtR4v3YyFx22jkl+gssbmKGKzOJuBJo+5dMwt0thj fJtEoZKe8uPRvas3Zvqs7WKeLo4jye7N8OHbsrqLQ9zfb7p0GKmT5RxzC w==; X-IronPort-AV: E=McAfee;i="6600,9927,10817"; a="372957213" X-IronPort-AV: E=Sophos;i="6.02,212,1688454000"; d="scan'208";a="372957213" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Aug 2023 22:16:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10817"; a="732464320" X-IronPort-AV: E=Sophos;i="6.02,212,1688454000"; d="scan'208";a="732464320" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.153]) by orsmga007.jf.intel.com with SMTP; 29 Aug 2023 22:16:44 -0700 Received: by stinkbox (sSMTP sendmail emulation); Wed, 30 Aug 2023 08:16:43 +0300 Date: Wed, 30 Aug 2023 08:16:43 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: "Golani, Mitulkumar Ajitkumar" Message-ID: References: <20230828054140.28054-1-ville.syrjala@linux.intel.com> <20230828054140.28054-6-ville.syrjala@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Patchwork-Hint: comment Subject: Re: [Intel-gfx] [PATCH 5/6] drm/i915: Adjust seamless_m_n flag behaviour 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: "intel-gfx@lists.freedesktop.org" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Tue, Aug 29, 2023 at 01:48:18PM +0000, Golani, Mitulkumar Ajitkumar wrote: > Hi Ville, > > Thanks for the inputs. > > I encountered an interesting observation while validating the changes. > In scenarios where VRR is by default ON from the panel, I noticed that during the first-time enabling of VRR, a full modeset is required due to a fastset requirement mismatch, as indicated in the logs. Which logs? > However, I also observed that after this, the function intel_crtc_needs_modeset returns 0, which typically implies a fastset operation. Any fastset always starts out as a full modeset, it will then be promoted (or demoted?) to a fastset by intel_crtc_check_fastset() if possible. > > Considering that both conditions can't hold simultaneously, there seems to be an inconsistency with underrun errors. > Could you kindly shed some light on this situation? I'm trying to align the log messages with the observed behavior and the function's return value. > > Your insights would be greatly appreciated. > > Regards, > Mitul > > > -----Original Message----- > > From: Ville Syrjälä > > Sent: 29 August 2023 13:51 > > To: Golani, Mitulkumar Ajitkumar > > > > Cc: intel-gfx@lists.freedesktop.org > > Subject: Re: [Intel-gfx] [PATCH 5/6] drm/i915: Adjust seamless_m_n flag > > behaviour > > > > On Mon, Aug 28, 2023 at 04:58:49PM +0000, Golani, Mitulkumar Ajitkumar > > wrote: > > > Hi Ville, > > > > > > > -----Original Message----- > > > > From: Intel-gfx On Behalf > > > > Of Ville Syrjala > > > > Sent: 28 August 2023 11:12 > > > > To: intel-gfx@lists.freedesktop.org > > > > Subject: [Intel-gfx] [PATCH 5/6] drm/i915: Adjust seamless_m_n flag > > > > behaviour > > > > > > > > From: Ville Syrjälä > > > > > > > > Make the seamless_m_n flag more like the update_pipe fastset flag, > > > > ie. the flag will only be set if we need to do the seamless M/N > > > > update, and in all other cases the flag is cleared. Also rename the > > > > flag to update_m_n to make it more clear it's similar to update_pipe. > > > > > > > > I believe special casing seamless_m_n like this makes sense as it > > > > also affects eg. vblank evasion. We can potentially avoid some > > > > vblank evasion tricks, simplify some checks, and hopefully will help with > > the VRR vs. M/N mess. > > > > > > > > Signed-off-by: Ville Syrjälä > > > > --- > > > > drivers/gpu/drm/i915/display/intel_atomic.c | 1 + > > > > drivers/gpu/drm/i915/display/intel_crtc.c | 2 +- > > > > drivers/gpu/drm/i915/display/intel_display.c | 22 +++++++++++-------- > > > > .../drm/i915/display/intel_display_types.h | 2 +- > > > > drivers/gpu/drm/i915/display/intel_dp.c | 2 +- > > > > 5 files changed, 17 insertions(+), 12 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c > > > > b/drivers/gpu/drm/i915/display/intel_atomic.c > > > > index 7cf51dd8c056..aaddd8c0cfa0 100644 > > > > --- a/drivers/gpu/drm/i915/display/intel_atomic.c > > > > +++ b/drivers/gpu/drm/i915/display/intel_atomic.c > > > > @@ -259,6 +259,7 @@ intel_crtc_duplicate_state(struct drm_crtc *crtc) > > > > drm_property_blob_get(crtc_state->post_csc_lut); > > > > > > > > crtc_state->update_pipe = false; > > > > + crtc_state->update_m_n = false; > > > > crtc_state->disable_lp_wm = false; > > > > crtc_state->disable_cxsr = false; > > > > crtc_state->update_wm_pre = false; diff --git > > > > a/drivers/gpu/drm/i915/display/intel_crtc.c > > > > b/drivers/gpu/drm/i915/display/intel_crtc.c > > > > index 1992e7060263..a04076064f02 100644 > > > > --- a/drivers/gpu/drm/i915/display/intel_crtc.c > > > > +++ b/drivers/gpu/drm/i915/display/intel_crtc.c > > > > @@ -510,7 +510,7 @@ static void > > > > intel_crtc_vblank_evade_scanlines(struct > > > > intel_atomic_state *state, > > > > * M/N is double buffered on the transcoder's undelayed vblank, > > > > * so with seamless M/N we must evade both vblanks. > > > > */ > > > > - if (new_crtc_state->seamless_m_n && > > > > intel_crtc_needs_fastset(new_crtc_state)) > > > > + if (new_crtc_state->update_m_n) > > > > *min -= adjusted_mode->crtc_vblank_start - > > > > adjusted_mode->crtc_vdisplay; } > > > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c > > > > b/drivers/gpu/drm/i915/display/intel_display.c > > > > index 632f1f58df9e..6196ef76390b 100644 > > > > --- a/drivers/gpu/drm/i915/display/intel_display.c > > > > +++ b/drivers/gpu/drm/i915/display/intel_display.c > > > > @@ -5170,7 +5170,7 @@ intel_pipe_config_compare(const struct > > > > intel_crtc_state *current_config, > > > > PIPE_CONF_CHECK_X(lane_lat_optim_mask); > > > > > > > > if (HAS_DOUBLE_BUFFERED_M_N(dev_priv)) { > > > > - if (!fastset || !pipe_config->seamless_m_n) > > > > + if (!fastset || !pipe_config->update_m_n) > > > > PIPE_CONF_CHECK_M_N(dp_m_n); > > > > } else { > > > > PIPE_CONF_CHECK_M_N(dp_m_n); > > > > @@ -5307,7 +5307,7 @@ intel_pipe_config_compare(const struct > > > > intel_crtc_state *current_config, > > > > if (IS_G4X(dev_priv) || DISPLAY_VER(dev_priv) >= 5) > > > > PIPE_CONF_CHECK_I(pipe_bpp); > > > > > > > > - if (!fastset || !pipe_config->seamless_m_n) { > > > > + if (!fastset || !pipe_config->update_m_n) { > > > > PIPE_CONF_CHECK_I(hw.pipe_mode.crtc_clock); > > > > PIPE_CONF_CHECK_I(hw.adjusted_mode.crtc_clock); > > > > } > > > > @@ -5402,6 +5402,7 @@ int intel_modeset_all_pipes(struct > > > > intel_atomic_state *state, > > > > > > > > crtc_state->uapi.mode_changed = true; > > > > crtc_state->update_pipe = false; > > > > + crtc_state->update_m_n = false; > > > > > > > > ret = drm_atomic_add_affected_connectors(&state->base, > > > > &crtc->base); > > > > @@ -5519,13 +5520,14 @@ static void intel_crtc_check_fastset(const > > > > struct intel_crtc_state *old_crtc_sta { > > > > struct drm_i915_private *i915 = to_i915(old_crtc_state->uapi.crtc- > > > > >dev); > > > > > > > > - if (!intel_pipe_config_compare(old_crtc_state, new_crtc_state, > > > > true)) { > > > > + if (!intel_pipe_config_compare(old_crtc_state, new_crtc_state, > > > > true)) > > > > drm_dbg_kms(&i915->drm, "fastset requirement not met, > > forcing > > > > full modeset\n"); > > > > + else > > > > + new_crtc_state->uapi.mode_changed = false; > > > > > > > > - return; > > > > - } > > > > + if (intel_crtc_needs_modeset(new_crtc_state)) > > > > + new_crtc_state->update_m_n = false; > > > > > > > > - new_crtc_state->uapi.mode_changed = false; > > > > if (!intel_crtc_needs_modeset(new_crtc_state)) > > > > new_crtc_state->update_pipe = true; } @@ -6240,6 +6242,7 > > @@ int > > > > intel_atomic_check(struct drm_device *dev, > > > > if (intel_cpu_transcoders_need_modeset(state, > > > > BIT(master))) { > > > > new_crtc_state->uapi.mode_changed = true; > > > > new_crtc_state->update_pipe = false; > > > > + new_crtc_state->update_m_n = false; > > > > } > > > > } > > > > > > > > @@ -6252,6 +6255,7 @@ int intel_atomic_check(struct drm_device > > *dev, > > > > if (intel_cpu_transcoders_need_modeset(state, > > > > trans)) { > > > > new_crtc_state->uapi.mode_changed = true; > > > > new_crtc_state->update_pipe = false; > > > > + new_crtc_state->update_m_n = false; > > > > } > > > > } > > > > > > > > @@ -6259,6 +6263,7 @@ int intel_atomic_check(struct drm_device > > *dev, > > > > if (intel_pipes_need_modeset(state, new_crtc_state- > > > > >bigjoiner_pipes)) { > > > > new_crtc_state->uapi.mode_changed = true; > > > > new_crtc_state->update_pipe = false; > > > > + new_crtc_state->update_m_n = false; > > > > } > > > > } > > > > } > > > > @@ -6437,7 +6442,7 @@ static void intel_pipe_fastset(const struct > > > > intel_crtc_state *old_crtc_state, > > > > IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv)) > > > > hsw_set_linetime_wm(new_crtc_state); > > > > > > > > - if (new_crtc_state->seamless_m_n) > > > > + if (new_crtc_state->update_m_n) > > > > intel_cpu_transcoder_set_m1_n1(crtc, new_crtc_state- > > > > >cpu_transcoder, > > > > &new_crtc_state->dp_m_n); } > > @@ -6573,8 +6578,7 @@ > > > > static void intel_update_crtc(struct intel_atomic_state *state, > > > > * > > > > * FIXME Should be synchronized with the start of vblank > > > > somehow... > > > > */ > > > > - if (vrr_enabling(old_crtc_state, new_crtc_state) || > > > > - (new_crtc_state->seamless_m_n && > > > > intel_crtc_needs_fastset(new_crtc_state))) > > > > + if (vrr_enabling(old_crtc_state, new_crtc_state) || > > > > +new_crtc_state->update_m_n) > > > > intel_crtc_update_active_timings(new_crtc_state, > > > > new_crtc_state->vrr.enable); > > > > > > In the context where a Push has already been sent, should the update > > occur when we enable VRR itself? I'm curious about the rationale for not > > updating it immediately upon enabling VRR. > > > > The active timings should really be updated synchronously with the > > hardware latching the new values. But that is actually impossible so some > > race conditions will always remain. > > > > I haven't actually verified how the hardware behaves when we enable VRR. > > I assume the VRR_CTL will get latched at the next start of vblank as well. > > But we should really try to confirm that on actual hardware. > > > > The case where we have VRR already enabled while updating M/N might go > > badly with the current order of doing things as the vblank irq may trigger > > immediately upon push. So for that case it would be better to update the > > active timings before the push. Or perhaps we should just make sure VRR is > > always disabled around M/N updates... > > > > > > > > Regards, > > > Mitul > > > > b/drivers/gpu/drm/i915/display/intel_display_types.h > > > > index 731f2ec04d5c..2367b030b469 100644 > > > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > > > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > > > > @@ -1083,6 +1083,7 @@ struct intel_crtc_state { > > > > > > > > unsigned fb_bits; /* framebuffers to flip */ > > > > bool update_pipe; /* can a fast modeset be performed? */ > > > > + bool update_m_n; /* update M/N seamlessly during fastset? */ > > > > bool disable_cxsr; > > > > bool update_wm_pre, update_wm_post; /* watermarks are > > updated */ > > > > bool fifo_changed; /* FIFO split is changed */ @@ -1195,7 +1196,6 > > > > @@ struct intel_crtc_state { > > > > /* m2_n2 for eDP downclock */ > > > > struct intel_link_m_n dp_m2_n2; > > > > bool has_drrs; > > > > - bool seamless_m_n; > > > > > > > > /* PSR is supported but might not be enabled due the lack of > > > > enabled planes */ > > > > bool has_psr; > > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c > > > > b/drivers/gpu/drm/i915/display/intel_dp.c > > > > index 05694e0b6143..ceab5b26b5e8 100644 > > > > --- a/drivers/gpu/drm/i915/display/intel_dp.c > > > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > > > > @@ -2535,7 +2535,7 @@ intel_dp_drrs_compute_config(struct > > > > intel_connector *connector, > > > > int pixel_clock; > > > > > > > > if (has_seamless_m_n(connector)) > > > > - pipe_config->seamless_m_n = true; > > > > + pipe_config->update_m_n = true; > > > > > > > > if (!can_enable_drrs(connector, pipe_config, downclock_mode)) { > > > > if (intel_cpu_transcoder_has_m2_n2(i915, pipe_config- > > > > >cpu_transcoder)) > > > > -- > > > > 2.41.0 > > > > > > > -- > > Ville Syrjälä > > Intel -- Ville Syrjälä Intel