From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: convert parisc to the generic dma-noncoherent code Date: Tue, 17 Jul 2018 15:19:52 +0200 Message-ID: <20180717131952.GF13582@lst.de> References: <20180619070455.26624-1-hch@lst.de> <20180711153445.GC31946@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Cc: James Bottomley , Helge Deller , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Christoph Hellwig , linux-parisc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: John David Anglin Return-path: In-Reply-To: List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org On Sun, Jul 15, 2018 at 12:29:37PM -0400, John David Anglin wrote: > On 2018-07-13 4:14 AM, Helge Deller wrote: >> On 11.07.2018 17:34, Christoph Hellwig wrote: >>> ping? Any comments? >> I applied those 3 patches on top of git head, and booted the >> 32-bit kernel on a HP 715/64 (PCX-L) and a HP B160L (PCX-L2). >> On both machines I had problems with those drivers which use >> DMA (I checked specifically the lasi NIC card, which is the >> main onboard NIC card in both machines). >> Getting IP via DHCP was unreliable, pings on the same network >> to both machines gave lost packets, login via ssh sometimes failed >> and so on. >> >> So, there is definitively some cache-flush missing in this patchset. > Possibly, the code should use flush_kernel_vmap_range() as it purges the = > TLB entries used > for the cache flush.=A0 Some of the routines in pci-dma.c currently use i= t. That might be worth a try and is already discussed in my description. Also it might be good to check that the last patch really is the culprit, I'm pretty certain it is, but a double check never hurts.