From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758212Ab3APQDi (ORCPT ); Wed, 16 Jan 2013 11:03:38 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:36112 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757773Ab3APQDe (ORCPT ); Wed, 16 Jan 2013 11:03:34 -0500 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Jani Nikula , Daniel Vetter , Herton Ronaldo Krzesinski Subject: [PATCH 096/222] drm/i915: drop buggy write to FDI_RX_CHICKEN register Date: Wed, 16 Jan 2013 13:54:56 -0200 Message-Id: <1358351822-7675-97-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1358351822-7675-1-git-send-email-herton.krzesinski@canonical.com> References: <1358351822-7675-1-git-send-email-herton.krzesinski@canonical.com> X-Extended-Stable: 3.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5.7.3 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Vetter commit 607a6f7a6621f65706ff536b2615ee65b5c2f575 upstream. Jani Nikula noticed that the parentheses are wrong and we & the bit with the register address instead of the read-back value. He sent a patch to correct that. On second look, we write the same register in the previous line, and the w/a seems to be to set FDI_RX_PHASE_SYNC_POINTER_OVR to enable the logic, then keep always set FDI_RX_PHASE_SYNC_POINTER_OVR and toggle FDI_RX_PHASE_SYNC_POINTER_EN before/after enabling the pc transcoder. So the right things seems to be to simply kill the 2nd write. Cc: Jani Nikula Reviewed-by: Chris Wilson [danvet: Dropped a bogus ~ from the commit message that somehow crept in.] Signed-off-by: Daniel Vetter [ herton: this looks a good bug fix, which also makes the next patch, "drm/i915: disable cpt phase pointer fdi rx workaround", easier to apply ] Signed-off-by: Herton Ronaldo Krzesinski --- drivers/gpu/drm/i915/intel_display.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index c69444a..98ea04e 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2609,9 +2609,6 @@ static void ironlake_fdi_disable(struct drm_crtc *crtc) /* Ironlake workaround, disable clock pointer after downing FDI */ if (HAS_PCH_IBX(dev)) { I915_WRITE(FDI_RX_CHICKEN(pipe), FDI_RX_PHASE_SYNC_POINTER_OVR); - I915_WRITE(FDI_RX_CHICKEN(pipe), - I915_READ(FDI_RX_CHICKEN(pipe) & - ~FDI_RX_PHASE_SYNC_POINTER_EN)); } else if (HAS_PCH_CPT(dev)) { cpt_phase_pointer_disable(dev, pipe); } -- 1.7.9.5