From mboxrd@z Thu Jan 1 00:00:00 1970 From: "hch@lst.de" Subject: Re: ensure dma_alloc_coherent always returns zeroed memory Date: Thu, 20 Dec 2018 15:34:15 +0100 Message-ID: <20181220143415.GA17726@lst.de> References: <20181214082515.14835-1-hch@lst.de> <20181219165939.GA26087@lst.de> <1545316369.14089.20.camel@synopsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1545316369.14089.20.camel@synopsys.com> Sender: linux-kernel-owner@vger.kernel.org To: Eugeniy Paltsev Cc: "hch@lst.de" , Vineet Gupta , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , "linux-s390@vger.kernel.org" , "linux-xtensa@linux-xtensa.org" , "linux-m68k@lists.linux-m68k.org" , "linux-alpha@vger.kernel.org" , "linux-snps-arc@lists.infradead.org" , "openrisc@lists.librecores.org" , "ashutosh.dixit@intel.com" , "linux-parisc@vger.kernel.org" , "linux-c6x-dev@linux-c6x.org" , monst List-Id: iommu@lists.linux-foundation.org On Thu, Dec 20, 2018 at 02:32:52PM +0000, Eugeniy Paltsev wrote: > Hi Christoph, > > I test kernel from your 'dma-alloc-always-zero' branch, and as > I can see we have DMA peripherals (like USB) broken. I would be really surprised if that is caused by the patch to add the zeroing. Can you check which commit caused the issue by bisecting from a known good baseline?