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 B8266C433F5 for ; Wed, 9 Mar 2022 17:02:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0E41210E582; Wed, 9 Mar 2022 17:02:27 +0000 (UTC) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id E156D10E57F for ; Wed, 9 Mar 2022 17:02:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1646845346; x=1678381346; h=from:to:subject:date:message-id:in-reply-to:references: mime-version:content-transfer-encoding; bh=+2Rr4zgvUokLjzBqc0qzAgKyUtkqyWlwsRwoDTB1RgQ=; b=kGc8nQWnsFeVdiikhYL4qA7KUMNUkeKAI+Ll+ehuzqVWRRsLxdwq9pWZ R6yYlpQki0MZtgq//fxTf2FkWUXTqyuc9b0TBowqgFOps6u4oMOYpT5jn hfokzl3r5Q9mL+Wj7UyLJfVgpdoQSGGppVpEHsbtYkXvtJiBiNRZIU0FU 33FQdzmILtLXFc/g2nxoYxUOz7b4EdcHlsxo33CprJ2TS5QUOlQVnh7cZ uQRwpjhdJ7Fml2n/+knB+Kf8RnwGWB9ASM0vcna/U1WBHtUBF2tuz79A0 GB9gjqqW+OeW6XGY4LAC8QPE6ZoFdfF766sn+gTclmtOy0vfM++9x6JeN Q==; X-IronPort-AV: E=McAfee;i="6200,9189,10281"; a="255217969" X-IronPort-AV: E=Sophos;i="5.90,167,1643702400"; d="scan'208";a="255217969" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Mar 2022 08:50:09 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,167,1643702400"; d="scan'208";a="578449090" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.151]) by orsmga001.jf.intel.com with SMTP; 09 Mar 2022 08:50:01 -0800 Received: by stinkbox (sSMTP sendmail emulation); Wed, 09 Mar 2022 18:50:01 +0200 From: Ville Syrjala To: intel-gfx@lists.freedesktop.org Date: Wed, 9 Mar 2022 18:49:44 +0200 Message-Id: <20220309164948.10671-5-ville.syrjala@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220309164948.10671-1-ville.syrjala@linux.intel.com> References: <20220309164948.10671-1-ville.syrjala@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Intel-gfx] [PATCH 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: , 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