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 C8333C433EF for ; Tue, 8 Mar 2022 17:41:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2F49310E2A7; Tue, 8 Mar 2022 17:41:05 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id C86EF10E2A7 for ; Tue, 8 Mar 2022 17:41:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1646761263; x=1678297263; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=+2Rr4zgvUokLjzBqc0qzAgKyUtkqyWlwsRwoDTB1RgQ=; b=TkTj5BPMLByWydUoW5rkMfVn6JwoF6T03UdimmTpF7QsmM2c0eyk0tWm f3RvuWtZqPHgzHEBQ+kQkuzUOB8hcsLK7OJZFbDOpPjlAasQw7jvxugEz MB24qxwHC6OgcMVbifNYjs+wAKJ6XBumaOB61Nh3GJ7KA1ykJVZe8Vlcn Owjwe7LzWGafOtNqMz5igxpW4vuvzgp5Ei/JbnA55U5GB0Tj20OrekHTJ XPC/Zy2Se9fLDqgcCsCGLZ0VvrYjPuC8byq3VBa25R0Ga7mgkgptcA8ZA FyDwlb27ynWDy1zQrumq6mbgs/stDPwo/s3QRJiEUntBT2oPnXyXUQlDt A==; X-IronPort-AV: E=McAfee;i="6200,9189,10280"; a="234713934" X-IronPort-AV: E=Sophos;i="5.90,165,1643702400"; d="scan'208";a="234713934" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Mar 2022 09:32:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,165,1643702400"; d="scan'208";a="687999590" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.151]) by fmsmga001.fm.intel.com with SMTP; 08 Mar 2022 09:32:45 -0800 Received: by stinkbox (sSMTP sendmail emulation); Tue, 08 Mar 2022 19:32:44 +0200 From: Ville Syrjala To: intel-gfx@lists.freedesktop.org Date: Tue, 8 Mar 2022 19:32:29 +0200 Message-Id: <20220308173230.4182-6-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220308173230.4182-1-ville.syrjala@linux.intel.com> References: <20220308173230.4182-1-ville.syrjala@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Intel-gfx] [PATCH 5/6] 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" 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 --- 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