From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59424 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754079AbeGEQGf (ORCPT ); Thu, 5 Jul 2018 12:06:35 -0400 Date: Thu, 5 Jul 2018 18:06:32 +0200 From: Greg KH To: Andrey Grodzovsky Cc: alexander.deucher@amd.com, harry.wentland@amd.com, michel.daenzer@amd.com, shirish.s@amd.com, stable@vger.kernel.org, stable-commits@vger.kernel.org Subject: Re: Patch "drm/amd/display: release spinlock before committing updates to stream" has been added to the 4.17-stable tree Message-ID: <20180705160632.GA7911@kroah.com> References: <1530806367175127@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: On Thu, Jul 05, 2018 at 12:05:09PM -0400, Andrey Grodzovsky wrote: > This patch is wrong as noted by MIchel a while ago - quote from his review > of the patch. > > "Actually, pflip_status should really only be set to AMDGPU_FLIP_SUBMITTED > after the flip has been programmed to the hardware, at least as far as the > lock holder is concerned. That's why the code was previously holding the > lock until after the dc_commit_updates_for_stream call. Otherwise, it's at > least theoretically possible that either: > > * dm_pflip_high_irq is called before dc_commit_updates_for_stream, but sees > flip_status == AMDGPU_FLIP_SUBMITTED and sends the event to userspace > prematurely > > * dm_pflip_high_irq is called after dc_commit_updates_for_stream, but sees > flip_status != AMDGPU_FLIP_SUBMITTED, so it incorrectly doesn't send the > event to userspace " > > It shouldn't go in. Is there a fix for this in Linus's tree for these problems? If not, why not? If so, what is that git commit id? thanks, greg k-h