From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756771AbaCQRIO (ORCPT ); Mon, 17 Mar 2014 13:08:14 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:54164 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755115AbaCQRIM (ORCPT ); Mon, 17 Mar 2014 13:08:12 -0400 Message-ID: <1395076090.2227.29.camel@dabdike.int.hansenpartnership.com> Subject: Re: DMA-API mapping errors in vmw_pvscsi From: James Bottomley To: Josh Boyer Cc: Arvind Kumar , VMware PV-Drivers , "linux-scsi@vger.kernel.org" , "Linux-Kernel@Vger. Kernel. Org" Date: Mon, 17 Mar 2014 10:08:10 -0700 In-Reply-To: References: Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.10.2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-03-17 at 12:52 -0400, Josh Boyer wrote: > Hi All, > > We've had a few reports[1][2] now on the vmw_pvscsi driver throwing > DMA-API mapping errors when the DMA_API_DEBUG option is enabled. I've > included one from a recent 3.14-rc6 kernel below. Looking at > vmw_pvscsi.c, I can see pvscsi_map_buffers is missing the calls to > pci_dma_mapping_error, which is what causes the warnings to be thrown. > > However, I'm not familiar with this driver and I can't see what the > proper error path should be in this case. pvscsi_map_buffers is a > void function and doesn't currently have the ability to return an > error to the caller. Even if it did, I'm not sure what the proper > response to an error should be. Thoughts? It's missing checking in two places: from pci_map_single() and on scsi_dma_map(). In the latter case, pvscsi_map_buffers needs to return an error code and then pvscsi_queue_ring can return -1. James