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 X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4FC57C433FE for ; Thu, 23 Sep 2021 13:23:44 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 1755661216 for ; Thu, 23 Sep 2021 13:23:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 1755661216 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 12AC16ED17; Thu, 23 Sep 2021 13:23:43 +0000 (UTC) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4992A6ED12 for ; Thu, 23 Sep 2021 13:23:42 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10115"; a="223871393" X-IronPort-AV: E=Sophos;i="5.85,316,1624345200"; d="scan'208";a="223871393" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Sep 2021 06:23:31 -0700 X-IronPort-AV: E=Sophos;i="5.85,316,1624345200"; d="scan'208";a="702711814" Received: from unknown (HELO intel.com) ([10.237.72.91]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Sep 2021 06:23:30 -0700 Date: Thu, 23 Sep 2021 16:24:21 +0300 From: "Lisovskiy, Stanislav" To: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Cc: intel-gfx@lists.freedesktop.org Message-ID: <20210923132421.GA11567@intel.com> References: <20210514125751.17075-1-ville.syrjala@linux.intel.com> <20210514125751.17075-6-ville.syrjala@linux.intel.com> <20210917153422.GB1224@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Subject: Re: [Intel-gfx] [PATCH 05/14] drm/i915: Fix HPLL watermark readout for g4x 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 Wed, Sep 22, 2021 at 05:05:12PM +0300, Ville Syrjälä wrote: > On Fri, Sep 17, 2021 at 06:34:22PM +0300, Lisovskiy, Stanislav wrote: > > On Fri, May 14, 2021 at 03:57:42PM +0300, Ville Syrjala wrote: > > > From: Ville Syrjälä > > > > > > If HPLL watermarks are already enabled, let's not mark them as > > > disabled by forgetting to bump 'level' before we call > > > g4x_raw_plane_wm_set(). > > > > > > Signed-off-by: Ville Syrjälä > > > --- > > > drivers/gpu/drm/i915/intel_pm.c | 7 +++++-- > > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > > > index 661bc6fdf38c..990ee5a590d3 100644 > > > --- a/drivers/gpu/drm/i915/intel_pm.c > > > +++ b/drivers/gpu/drm/i915/intel_pm.c > > > @@ -6468,7 +6468,8 @@ void g4x_wm_get_hw_state(struct drm_i915_private *dev_priv) > > > for_each_plane_id_on_crtc(crtc, plane_id) > > > raw->plane[plane_id] = active->wm.plane[plane_id]; > > > > > > - if (++level > max_level) > > > + level = G4X_WM_LEVEL_SR; > > > + if (level > max_level) > > > > Do I understand correctly that its basically identical to what > > was before, so this is done here just for it to look more explicit? > > > > I.e we had for example max_level G4X_WM_LEVEL_SR and level G4X_WM_LEVEL_NORMAL > > , after ++level it will anyway become G4X_WM_LEVEL_SR and same for next one. > > > > > > > goto out; > > > > > > raw = &crtc_state->wm.g4x.raw[level]; > > > @@ -6477,7 +6478,8 @@ void g4x_wm_get_hw_state(struct drm_i915_private *dev_priv) > > > raw->plane[PLANE_SPRITE0] = 0; > > > raw->fbc = active->sr.fbc; > > > > > > - if (++level > max_level) > > > + level = G4X_WM_LEVEL_HPLL; > > > + if (level > max_level) > > > goto out; > > > > > > raw = &crtc_state->wm.g4x.raw[level]; > > > @@ -6486,6 +6488,7 @@ void g4x_wm_get_hw_state(struct drm_i915_private *dev_priv) > > > raw->plane[PLANE_SPRITE0] = 0; > > > raw->fbc = active->hpll.fbc; > > > > > > + level++; > > > > Hi Ville, > > > > So if we reached here, it means level = G4X_WM_LEVEL_HPLL, which is > > the max wm level defined, why are we then incrementing it even more? > > > > the g4x_raw_plane_wm_set will be using that value as a level: > > > > for (; level < intel_wm_num_levels(dev_priv); level++) { > > struct g4x_pipe_wm *raw = &crtc_state->wm.g4x.raw[level]; > > > > dirty |= raw->plane[plane_id] != value; > > raw->plane[plane_id] = value; > > } > > > > however level then will be equal to NUM_G4X_WM_LEVELS, which is actually > > an illegal value, or is that an expected behaviour? > > > > Just trying to understand, whats happening here, before stamping an r-b :) > > > > Stan > > > > > > > out: > > > for_each_plane_id_on_crtc(crtc, plane_id) > > > g4x_raw_plane_wm_set(crtc_state, level, > > Right, so the code is basically this: > > level = G4X_WM_LEVEL_SR; > if (level > max_level) > goto out; > level = G4X_WM_LEVEL_HPLL; > if (level > max_level) > goto out; > level++ /* ie. level=NUM_G4X_WM_LEVELS */ > out: > invalidate_raw_watermarks_starting_from_level(level); > > So if we take the first goto we want to invalidate all > watermarks starting from SR, second goto wants to invalidate > all watermarks starting from HPLL, and if we didn't take either > goto we don't want to invalidate any watermarks because we deemed > everything up to and including HPLL is ok. So we can't just > leave level==G4X_WM_LEVEL_HPLL or else the code would still invalidate > the HPLL watermarks. Instead we level++ so that the invalidate call > becomes a nop. > > The other option I suppose would be to skip the invalidation stuff > if we didn't take either of the gotos, but I'm thinking that would make > the code more messy. Ah ok, thought its setting wm levels, but if its actually invalidating, makes sense. Probably that is why it uses USHRT_MAX as a value. Thanks for the clarification. Reviewed-by: Stanislav Lisovskiy > > -- > Ville Syrjälä > Intel