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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 0C4D2C32789 for ; Tue, 6 Nov 2018 21:30:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF8702086C for ; Tue, 6 Nov 2018 21:30:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF8702086C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730824AbeKGG5p (ORCPT ); Wed, 7 Nov 2018 01:57:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44058 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726069AbeKGG5o (ORCPT ); Wed, 7 Nov 2018 01:57:44 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C4840A402A; Tue, 6 Nov 2018 21:30:31 +0000 (UTC) Received: from malachite.bss.redhat.com (dhcp-10-20-1-11.bss.redhat.com [10.20.1.11]) by smtp.corp.redhat.com (Postfix) with ESMTP id D40F1600C4; Tue, 6 Nov 2018 21:30:30 +0000 (UTC) From: Lyude Paul To: intel-gfx@lists.freedesktop.org Cc: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Rodrigo Vivi , Jani Nikula , Joonas Lahtinen , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 3/5] drm/i915: Fix threshold check in intel_hpd_irq_storm_detect() Date: Tue, 6 Nov 2018 16:30:14 -0500 Message-Id: <20181106213017.14563-4-lyude@redhat.com> In-Reply-To: <20181106213017.14563-1-lyude@redhat.com> References: <20181106213017.14563-1-lyude@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Tue, 06 Nov 2018 21:30:32 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently in intel_hpd_irq_storm_detect() when we detect that the last recorded hotplug wasn't within the period defined by HPD_STORM_DETECT_DELAY, we make the mistake of resetting the HPD count to 0 without incrementing it. This results in us only enabling storm detection when we go +2 above the threshold, e.g. an HPD threshold of 5 would not trigger a storm until we reach a total of 7 hotplugs. So: rework the code a bit so we reset the HPD count when HPD_STORM_DETECT_DELAY has passed, then increment the count afterwards. Also, clean things up a bit to make it easier to undertand. Signed-off-by: Lyude Paul Reviewed-by: Ville Syrjälä Cc: Rodrigo Vivi --- drivers/gpu/drm/i915/intel_hotplug.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c index 8326900a311e..c11d73de16f2 100644 --- a/drivers/gpu/drm/i915/intel_hotplug.c +++ b/drivers/gpu/drm/i915/intel_hotplug.c @@ -135,24 +135,27 @@ enum hpd_pin intel_hpd_pin_default(struct drm_i915_private *dev_priv, static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv, enum hpd_pin pin) { - unsigned long start = dev_priv->hotplug.stats[pin].last_jiffies; + struct i915_hotplug *hpd = &dev_priv->hotplug; + unsigned long start = hpd->stats[pin].last_jiffies; unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD); - const int threshold = dev_priv->hotplug.hpd_storm_threshold; + const int threshold = hpd->hpd_storm_threshold; bool storm = false; + if (!threshold) + return false; + if (!time_in_range(jiffies, start, end)) { - dev_priv->hotplug.stats[pin].last_jiffies = jiffies; - dev_priv->hotplug.stats[pin].count = 0; - DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: 0\n", pin); - } else if (dev_priv->hotplug.stats[pin].count > threshold && - threshold) { - dev_priv->hotplug.stats[pin].state = HPD_MARK_DISABLED; + hpd->stats[pin].last_jiffies = jiffies; + hpd->stats[pin].count = 0; + } + + if (++hpd->stats[pin].count > threshold) { + hpd->stats[pin].state = HPD_MARK_DISABLED; DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", pin); storm = true; } else { - dev_priv->hotplug.stats[pin].count++; DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", pin, - dev_priv->hotplug.stats[pin].count); + hpd->stats[pin].count); } return storm; -- 2.19.1