From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:56652 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755000AbeDTONV (ORCPT ); Fri, 20 Apr 2018 10:13:21 -0400 Date: Fri, 20 Apr 2018 16:13:14 +0200 From: Greg Kroah-Hartman To: Takashi Iwai Cc: stable@vger.kernel.org, Christoph Hellwig Subject: Re: [PATCH 4.16.y] swiotlb: fix unexpected swiotlb_alloc_coherent failures Message-ID: <20180420141314.GA24101@kroah.com> References: <20180419061909.3297-1-tiwai@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180419061909.3297-1-tiwai@suse.de> Sender: stable-owner@vger.kernel.org List-ID: On Thu, Apr 19, 2018 at 08:19:09AM +0200, Takashi Iwai wrote: > commit 9e7f06c8beee304ee21b791653fefcd713f48b9a upstream. > > The code refactoring by commit 0176adb00406 ("swiotlb: refactor coherent > buffer allocation") made swiotlb_alloc_buffer almost always failing due > to a thinko: namely, the function evaluates the dma_coherent_ok call > incorrectly and dealing as if it's invalid. This ends up with weird > errors like iwlwifi probe failure or amdgpu screen flickering. > > This patch corrects the logic error. > > Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1088658 > Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1088902 > Fixes: 0176adb00406 ("swiotlb: refactor coherent buffer allocation") > Cc: # v4.16+ > Signed-off-by: Takashi Iwai > Signed-off-by: Christoph Hellwig > --- > > Greg, this is a commit that felt out in the previous round due to > cherry-pick error. Resent with a context fix. Now queued up, thanks. greg k-h