From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755004AbaFJTve (ORCPT ); Tue, 10 Jun 2014 15:51:34 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:35279 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753556AbaFJTvb (ORCPT ); Tue, 10 Jun 2014 15:51:31 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Jani Nikula , Egbert Eich , bitlord , Daniel Vetter , Jani Nikula , Kamal Mostafa Subject: [PATCH 3.13 108/160] drm/i915: Don't WARN nor handle unexpected hpd interrupts on gmch platforms Date: Tue, 10 Jun 2014 12:45:48 -0700 Message-Id: <1402429600-20477-109-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1402429600-20477-1-git-send-email-kamal@canonical.com> References: <1402429600-20477-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.3 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Vetter commit 3ff04a160a891e56cdcee5c198d4c764d1c8c78b upstream. The status bits are unconditionally set, the control bits only enable the actual interrupt generation. Which means if we get some random other interrupts we'll bogusly complain about them. So restrict the WARN to platforms with a sane hotplug interrupt handling scheme. And even more important also don't attempt to process the hpd bit since we've detected a storm already. Instead just clear the bit silently. This WARN has been introduced in commit b8f102e8bf71cacf33326360fdf9dcfd1a63925b Author: Egbert Eich Date: Fri Jul 26 14:14:24 2013 +0200 drm/i915: Add messages useful for HPD storm detection debugging (v2) before that we silently handled the hpd event and so partially defeated the storm detection. v2: Pimp commit message (Jani) Cc: Jani Nikula Cc: Egbert Eich Cc: bitlord Reported-by: bitlord Signed-off-by: Daniel Vetter Signed-off-by: Jani Nikula [ kamal: backport to 3.13-stable: context ] Signed-off-by: Kamal Mostafa --- drivers/gpu/drm/i915/i915_irq.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 9702704..4ad5cc5 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1234,9 +1234,20 @@ static inline void intel_hpd_irq_handler(struct drm_device *dev, spin_lock(&dev_priv->irq_lock); for (i = 1; i < HPD_NUM_PINS; i++) { - WARN(((hpd[i] & hotplug_trigger) && - dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED), - "Received HPD interrupt although disabled\n"); + if (hpd[i] & hotplug_trigger && + dev_priv->hpd_stats[i].hpd_mark == HPD_DISABLED) { + /* + * On GMCH platforms the interrupt mask bits only + * prevent irq generation, not the setting of the + * hotplug bits itself. So only WARN about unexpected + * interrupts on saner platforms. + */ + WARN_ONCE(INTEL_INFO(dev)->gen >= 5 && !IS_VALLEYVIEW(dev), + "Received HPD interrupt (0x%08x) on pin %d (0x%08x) although disabled\n", + hotplug_trigger, i, hpd[i]); + + continue; + } if (!(hpd[i] & hotplug_trigger) || dev_priv->hpd_stats[i].hpd_mark != HPD_ENABLED) -- 1.9.1