Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754384AbaLNUrd (ORCPT ); Sun, 14 Dec 2014 15:47:33 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:52947 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751411AbaLNUVr (ORCPT ); Sun, 14 Dec 2014 15:21:47 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Vetter , lu hua , Paulo Zanoni , Jani Nikula Subject: [PATCH 3.14 10/34] drm/i915: More cautious with pch fifo underruns Date: Sun, 14 Dec 2014 12:20:48 -0800 Message-Id: <20141214201804.090759807@linuxfoundation.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <20141214201803.791392744@linuxfoundation.org> References: <20141214201803.791392744@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Vetter commit b68362278af94e1171f5be9d4e44988601fb0439 upstream. Apparently PCH fifo underruns are tricky, we have plenty reports that we see the occasional underrun (especially at boot-up). So for a change let's see what happens when we don't re-enable pch fifo underrun reporting when the pipe is disabled. This means that the kernel can't catch pch fifo underruns when they happen (except when all pipes are on on the pch). But we'll still catch underruns when disabling the pipe again. So not a terrible reduction in test coverage. Since the DRM_ERROR is new and hence a regression plan B would be to revert it back to a debug output. Which would be a lot worse than this hack for underrun test coverage in the wild. See the referenced discussions for more. References: http://mid.gmane.org/CA+gsUGRfGe3t4NcjdeA=qXysrhLY3r4CEu7z4bjTwxi1uOfy+g@mail.gmail.com Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85898 References: https://bugs.freedesktop.org/show_bug.cgi?id=85898 References: https://bugs.freedesktop.org/show_bug.cgi?id=86233 References: https://bugs.freedesktop.org/show_bug.cgi?id=86478 Signed-off-by: Daniel Vetter Tested-by: lu hua Reviewed-by: Paulo Zanoni Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_display.c | 2 -- 1 file changed, 2 deletions(-) --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3817,7 +3817,6 @@ static void ironlake_crtc_disable(struct ironlake_fdi_disable(crtc); ironlake_disable_pch_transcoder(dev_priv, pipe); - intel_set_pch_fifo_underrun_reporting(dev, pipe, true); if (HAS_PCH_CPT(dev)) { /* disable TRANS_DP_CTL */ @@ -3883,7 +3882,6 @@ static void haswell_crtc_disable(struct if (intel_crtc->config.has_pch_encoder) { lpt_disable_pch_transcoder(dev_priv); - intel_set_pch_fifo_underrun_reporting(dev, TRANSCODER_A, true); intel_ddi_fdi_disable(crtc); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/