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 ACA61C433EF for ; Wed, 16 Mar 2022 17:57:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 32C1010E91F; Wed, 16 Mar 2022 17:57:29 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id 416DE10E91F for ; Wed, 16 Mar 2022 17:57:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647453447; x=1678989447; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=GB9nqNMTsV/me4qm2zHrsPt9J0yZ+zImoQAp45EqDPc=; b=gwpi17aPFfauu0SB/eoauHU54DEY0NJ28QwhJ777BhKam2gXLcnRsyRe FsowIU08OkfRtGSv53nstXsZ1mVxxzHnXbNRGF2XgWS4E32wj0PWz2qtG Kh+a2TQScYJ8cXSDzryctM/DBy2cqKvN8QePEzMGgw9inUawLGxWRAnfc FSSmvHguXa+U1IlmRw9vKyG5qiv2OAPfbyI0cFiSPHcX13hqeZn05Bao8 NAkR5LAWz62hgyhMALV8izA54OmX8YCC/a18A6fb2jGhZ2Ca6AJzBtVZw kbqLd2HUhJCjVexC89OEzo3oZbd4s4Pij278v2a6uM/GSK+ok/k8w7HdT A==; X-IronPort-AV: E=McAfee;i="6200,9189,10288"; a="236622862" X-IronPort-AV: E=Sophos;i="5.90,187,1643702400"; d="scan'208";a="236622862" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2022 10:57:26 -0700 X-IronPort-AV: E=Sophos;i="5.90,187,1643702400"; d="scan'208";a="690676530" Received: from unknown (HELO intel.com) ([10.237.72.65]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2022 10:57:25 -0700 Date: Wed, 16 Mar 2022 19:58:00 +0200 From: "Lisovskiy, Stanislav" To: Ville Syrjala Message-ID: <20220316175800.GG21723@intel.com> References: <20220309164948.10671-1-ville.syrjala@linux.intel.com> <20220309164948.10671-5-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: <20220309164948.10671-5-ville.syrjala@linux.intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) Subject: Re: [Intel-gfx] [PATCH v2 4/8] drm/i915: Reject excessive SAGV block time 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 Wed, Mar 09, 2022 at 06:49:44PM +0200, Ville Syrjala wrote: > From: Ville Syrjälä > > If the mailbox returns an exceesively large SAGV block time let's just > reject it. This avoids having to worry about overflows when we add the > SAGV block time to the wm0 latency. > > We shall put the limit arbitrarily at U16_MAX. >65msec latency > doesn't really make sense to me in any case. > > Signed-off-by: Ville Syrjälä Reviewed-by: Stanislav Lisovskiy > --- > drivers/gpu/drm/i915/intel_pm.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > index 36f5bccabf64..166246fa27e4 100644 > --- a/drivers/gpu/drm/i915/intel_pm.c > +++ b/drivers/gpu/drm/i915/intel_pm.c > @@ -3716,6 +3716,12 @@ static void intel_sagv_init(struct drm_i915_private *i915) > drm_dbg_kms(&i915->drm, "SAGV supported: %s, original SAGV block time: %u us\n", > str_yes_no(intel_has_sagv(i915)), i915->sagv_block_time_us); > > + /* avoid overflow when adding with wm0 latency/etc. */ > + if (drm_WARN(&i915->drm, i915->sagv_block_time_us > U16_MAX, > + "Excessive SAGV block time %u, ignoring\n", > + i915->sagv_block_time_us)) > + i915->sagv_block_time_us = 0; > + > if (!intel_has_sagv(i915)) > i915->sagv_block_time_us = 0; > } > -- > 2.34.1 >