From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53238 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933324AbbHJVfQ (ORCPT ); Mon, 10 Aug 2015 17:35:16 -0400 Subject: Patch "drm/i915: Replace WARN inside I915_READ64_2x32 with retry loop" has been added to the 4.1-stable tree To: chris@chris-wilson.co.uk, daniel.vetter@ffwll.ch, gregkh@linuxfoundation.org, michal.winiarski@intel.com Cc: , From: Date: Mon, 10 Aug 2015 14:35:15 -0700 Message-ID: <14392425152517@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled drm/i915: Replace WARN inside I915_READ64_2x32 with retry loop to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-i915-replace-warn-inside-i915_read64_2x32-with-retry-loop.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From ee0a227b7ac6e75f28e10269f81c7ec6eb600952 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 15 Jul 2015 09:50:42 +0100 Subject: drm/i915: Replace WARN inside I915_READ64_2x32 with retry loop MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Chris Wilson commit ee0a227b7ac6e75f28e10269f81c7ec6eb600952 upstream. Since we may conceivably encounter situations where the upper part of the 64bit register changes between reads, for example when a timestamp counter overflows, change the WARN into a retry loop. Signed-off-by: Chris Wilson Cc: Michał Winiarski Signed-off-by: Daniel Vetter Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/i915_drv.h | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3190,15 +3190,14 @@ int intel_freq_opcode(struct drm_i915_pr #define I915_READ64(reg) dev_priv->uncore.funcs.mmio_readq(dev_priv, (reg), true) #define I915_READ64_2x32(lower_reg, upper_reg) ({ \ - u32 upper = I915_READ(upper_reg); \ - u32 lower = I915_READ(lower_reg); \ - u32 tmp = I915_READ(upper_reg); \ - if (upper != tmp) { \ - upper = tmp; \ - lower = I915_READ(lower_reg); \ - WARN_ON(I915_READ(upper_reg) != upper); \ - } \ - (u64)upper << 32 | lower; }) + u32 upper, lower, tmp; \ + tmp = I915_READ(upper_reg); \ + do { \ + upper = tmp; \ + lower = I915_READ(lower_reg); \ + tmp = I915_READ(upper_reg); \ + } while (upper != tmp); \ + (u64)upper << 32 | lower; }) #define POSTING_READ(reg) (void)I915_READ_NOTRACE(reg) #define POSTING_READ16(reg) (void)I915_READ16_NOTRACE(reg) Patches currently in stable-queue which might be from chris@chris-wilson.co.uk are queue-4.1/drm-i915-declare-the-swizzling-unknown-for-l-shaped-configurations.patch queue-4.1/drm-i915-replace-warn-inside-i915_read64_2x32-with-retry-loop.patch