From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45424 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753794AbeDVN4y (ORCPT ); Sun, 22 Apr 2018 09:56:54 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Takashi Iwai , Christoph Hellwig , Jean Delvare Subject: [PATCH 4.16 058/196] swiotlb: fix unexpected swiotlb_alloc_coherent failures Date: Sun, 22 Apr 2018 15:51:18 +0200 Message-Id: <20180422135107.210672134@linuxfoundation.org> In-Reply-To: <20180422135104.278511750@linuxfoundation.org> References: <20180422135104.278511750@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai 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 Cc: Jean Delvare Signed-off-by: Greg Kroah-Hartman --- lib/swiotlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -732,7 +732,7 @@ swiotlb_alloc_buffer(struct device *dev, goto out_warn; *dma_handle = swiotlb_phys_to_dma(dev, phys_addr); - if (dma_coherent_ok(dev, *dma_handle, size)) + if (!dma_coherent_ok(dev, *dma_handle, size)) goto out_unmap; memset(phys_to_virt(phys_addr), 0, size);