From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751451AbbCJEpJ (ORCPT ); Tue, 10 Mar 2015 00:45:09 -0400 Received: from mail-wi0-f180.google.com ([209.85.212.180]:44684 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750773AbbCJEpG (ORCPT ); Tue, 10 Mar 2015 00:45:06 -0400 Date: Tue, 10 Mar 2015 05:45:01 +0100 From: Ingo Molnar To: Nicholas Krause Cc: bhelgaas@google.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RESEND] x86:pci: Change sta2x11_dma_ops stucture to use switolb_dma_supported as it's dma_supported function in sta2x11-fixup.c Message-ID: <20150310044500.GA9015@gmail.com> References: <1425959625-14551-1-git-send-email-xerofoify@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1425959625-14551-1-git-send-email-xerofoify@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Nicholas Krause wrote: > This changes the structure sta2x11_dma_ops stucture to use switolb_dma_supported as it's > function for dma_supported hardware verus setting this value to NULL as this should be set > correctly for when dma_supported function needs to be called for hardware needing this > function to be supported. Otherwise hardware needing this function to be supported will > either cause a kernel panic or oops due to a NULL pointer being dereferenced in the > structure, sta1x11_dma_ops for the dma_supported function. Further more in order to > prevent a kernel panic or oops here due to a NULL pointer being deferred here we add the > function, swiotlb_dma_supported as the dma_supported function for the structure, > sta2x11_dma_ops. Pleasedontresendtotallyunstructuredandunreadablechangelogs. You also (still) don't explain where and how this supposed crash might happen in practice. Please don't resend unless you've addressed those deficiencies. I.e. I'm not convinced you know what you are modifying there and what effects your modifications will have. Thanks, Ingo