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 6F55FC3DA79 for ; Mon, 15 Jan 2024 09:24:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 88B0D10E116; Mon, 15 Jan 2024 09:24:16 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8996910E116 for ; Mon, 15 Jan 2024 09:24:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1705310655; x=1736846655; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=tHCW2zz8wo+xl4Ovrw2Lc2Rn+4RBC8IhNgBUY/Zr54o=; b=UDDULbf+7+Cnj8fESAvcX0xtnC4NUVCQeKrQFHyUQN99QI/bwsxVIENS XKMEYwbRelpxHGnWLGb123mOyoMnFjZzalP0jS1r7eLfse5oMPddYn4YM ydpRDuiki/vSyR9molj20JBN99B7PvqWrj54LwZ90ioesF9df5HHvn97i MkcDvTpleqQ8YYo0wuU+ER1EG+IMA8wvTgZ9egRJXEQ3XKH6x3yPIHtzu 8Zzs4Tu6iOQSFViyusdeNGIrVqmRrfuglGJxwG5ZSMNq1ElI32OUaoBvL CCsxDTMj9mHyX0nvZYShFvuRBktc3AemcgaYfwvsVpLVlf3ezrbAecnzI w==; X-IronPort-AV: E=McAfee;i="6600,9927,10953"; a="485734069" X-IronPort-AV: E=Sophos;i="6.04,196,1695711600"; d="scan'208";a="485734069" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jan 2024 01:24:14 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10953"; a="776685388" X-IronPort-AV: E=Sophos;i="6.04,196,1695711600"; d="scan'208";a="776685388" Received: from unknown (HELO intel.com) ([10.237.72.65]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jan 2024 01:24:09 -0800 Date: Mon, 15 Jan 2024 11:24:06 +0200 From: "Lisovskiy, Stanislav" To: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [PATCH 2/3] drm/i915/bigjoiner: Refactor bigjoiner state readout Message-ID: References: <20240108120725.20057-1-stanislav.lisovskiy@intel.com> <20240108120725.20057-3-stanislav.lisovskiy@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-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 Fri, Jan 12, 2024 at 06:42:15PM +0200, Ville Syrjälä wrote: > On Mon, Jan 08, 2024 at 02:07:24PM +0200, Stanislav Lisovskiy wrote: > > Don't call enabled_bigjoiner_pipes twice, lets just move > > intel_get_bigjoiner_config earlier, because it is anyway > > calling same function. > > Also cleanup hsw_enabled_transcoders from irrelevant bigjoiner code. > > It's not irrelevant. The function is supposed to return the set of > enabled transcoders associated with the pipe. With this change the > function no longer does what it says on the tin. Yes, but I guess it is just a matter what we define to be higher in a logical hierarchy: a pipe or a bigjoiner? I thought it won't harm hsw_enabled_transcoders won't have any excess logic and will return only transcoders naturally associated with a physical pipe, while for higher complexity level constructs like bigjoiner we would have some logic on top. In fact my main motivation was to avoid calling enabled_bigjoiner_pipe as it is quite heavy and call intel_crtc_is_bigjoiner_slave here instead. enabled_bigjoiner_pipes reads too much information, which we don't need in that function(here we just need to know if we are slave or master) The absolute need for calling enabled_bigjoiner_pipes happens in intel_bigjoiner_get_config, which we moved earlier, which seems to be logical since hsw_get_transcoder_state needs to have bigjoiner info and now we can use its results to call more lightweight intel_crtc_is_bigjoiner_slave there because pipe_config->bigjoiner_pipes is now initialized, so we avoid calling enabled_bigjoiner_pipes second time.. > > > > > Signed-off-by: Stanislav Lisovskiy > > --- > > drivers/gpu/drm/i915/display/intel_display.c | 22 ++++++++++---------- > > 1 file changed, 11 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c > > index 927d124457b61..eec76ec167069 100644 > > --- a/drivers/gpu/drm/i915/display/intel_display.c > > +++ b/drivers/gpu/drm/i915/display/intel_display.c > > @@ -3525,7 +3525,6 @@ static u8 hsw_enabled_transcoders(struct intel_crtc *crtc) > > struct drm_i915_private *dev_priv = to_i915(dev); > > u8 panel_transcoder_mask = hsw_panel_transcoders(dev_priv); > > enum transcoder cpu_transcoder; > > - u8 master_pipes, slave_pipes; > > u8 enabled_transcoders = 0; > > > > /* > > @@ -3576,15 +3575,6 @@ static u8 hsw_enabled_transcoders(struct intel_crtc *crtc) > > if (transcoder_ddi_func_is_enabled(dev_priv, cpu_transcoder)) > > enabled_transcoders |= BIT(cpu_transcoder); > > > > - /* bigjoiner slave -> consider the master pipe's transcoder as well */ > > - enabled_bigjoiner_pipes(dev_priv, &master_pipes, &slave_pipes); > > - if (slave_pipes & BIT(crtc->pipe)) { > > - cpu_transcoder = (enum transcoder) > > - get_bigjoiner_master_pipe(crtc->pipe, master_pipes, slave_pipes); > > - if (transcoder_ddi_func_is_enabled(dev_priv, cpu_transcoder)) > > - enabled_transcoders |= BIT(cpu_transcoder); > > - } > > - > > return enabled_transcoders; > > } > > > > @@ -3631,6 +3621,15 @@ static bool hsw_get_transcoder_state(struct intel_crtc *crtc, > > u32 tmp; > > > > enabled_transcoders = hsw_enabled_transcoders(crtc); > > + > > + /* bigjoiner slave -> consider the master pipe's transcoder as well */ > > + if (intel_crtc_is_bigjoiner_slave(pipe_config)) { > > + unsigned long cpu_transcoder = (enum transcoder) > > + bigjoiner_master_pipe(pipe_config); > > + if (transcoder_ddi_func_is_enabled(dev_priv, cpu_transcoder)) > > + enabled_transcoders |= BIT(cpu_transcoder); > > + } > > + > > if (!enabled_transcoders) > > return false; > > > > @@ -3735,6 +3734,8 @@ static bool hsw_get_pipe_config(struct intel_crtc *crtc, > > > > pipe_config->shared_dpll = NULL; > > > > + intel_bigjoiner_get_config(pipe_config); > > So this is what avoids the "call it twice" part, but it also makes the > state potentially inconsistent as in all other cases we leave everything > zeroed if the transcoder is not enabled. So I'm not sure this is > entirely safe or whether we could end up with some weird state > mismatches due to the inconsistency. Isn't it vice versa? intel_bigjoiner_get_config is now called way earlier, before hsw_get_transcoder_state is called(previously it was called later), the only difference is just that we now have pipe_config->bigjoiner_pipes filled and enabled_bigjoiner_pipes was called there, so we can now use that info to call intel_crtc_is_bigjoiner_slave in hsw_get_transcoder_state, as I mentioned above. Also if none of the transcoders are enabled, we now in fact have more information filled than before this change(before we had only enabled_bigjoiner_pipes called in hsw_get_transcoder_state, but now we have also pipe_config->bigjoiner_pipes initialized), otherwise if none of the transcoders are active everything should be pretty much the same. Stan > > Why do you think calling it twice is problematic? It's supposed to be > idempotent (ignoring the actual register reads/etc.). > > > + > > active = hsw_get_transcoder_state(crtc, pipe_config, &crtc->hw_readout_power_domains); > > > > if ((IS_GEMINILAKE(dev_priv) || IS_BROXTON(dev_priv)) && > > @@ -3746,7 +3747,6 @@ static bool hsw_get_pipe_config(struct intel_crtc *crtc, > > if (!active) > > goto out; > > > > - intel_bigjoiner_get_config(pipe_config); > > intel_dsc_get_config(pipe_config); > > > > if (!transcoder_is_dsi(pipe_config->cpu_transcoder) || > > -- > > 2.37.3 > > -- > Ville Syrjälä > Intel