From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michel =?ISO-8859-1?Q?D=E4nzer?= Subject: Re: [PATCH] drm/radeon: fix VM page table setup on SI Date: Fri, 29 Jun 2012 18:14:31 +0200 Message-ID: <1340986471.3562.223.camel@thor.local> References: <1340920387-28720-1-git-send-email-alexdeucher@gmail.com> <1340981383.3562.200.camel@thor.local> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail.gna.ch (darkcity.gna.ch [195.226.6.51]) by gabe.freedesktop.org (Postfix) with ESMTP id 6A3179E9BA for ; Fri, 29 Jun 2012 09:14:43 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: Jerome Glisse Cc: dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org On Fre, 2012-06-29 at 11:28 -0400, Jerome Glisse wrote: = > On Fri, Jun 29, 2012 at 11:23 AM, Alex Deucher wr= ote: > > On Fri, Jun 29, 2012 at 10:49 AM, Michel D=E4nzer = wrote: > >> On Don, 2012-06-28 at 17:53 -0400, alexdeucher@gmail.com wrote: > >>> From: Alex Deucher > >>> > >>> Cayman and trinity allow for variable sized VM page > >>> tables, but SI requires that all page tables be the > >>> same size. The current code assumes variablely sized > >>> VM page tables so SI may end up with part of each page > >>> table overlapping with other memory which could end > >>> up being interpreted by the VM hw as garbage. > >>> > >>> Change the code to better accomodate SI. Allocate enough > >>> space for at least 2 full page tables and always set > >>> last_pfn to max_pfn on SI so each VM is backed by a full > >>> page table. This limits us to only 2 VMs active at any > >>> given time on SI. This will be rectified and the code can > >>> be reunified once we move to two level page tables. > >>> > >>> Signed-off-by: Alex Deucher > >> > >> This change breaks the radeonsi driver for me. egltri_screen (the > >> 'golden' test for radeonsi at least basically working) locks up the > >> GPU. > >> > >> I don't have any details about the lockup yet, as the GPU reset attempt > >> hangs the machine. Any ideas offhand what radeonsi might be doing wron= g? > > > > Maybe trying to access an unmapped page that happened to work by > > accident before and now causes a fault in the VM which halts the MC? Indeed, looks like it: radeon 0000:01:00.0: VM_CONTEXT1_PROTECTION_FAULT_ADDR 0x000FF01B radeon 0000:01:00.0: VM_CONTEXT1_PROTECTION_FAULT_STATUS 0x0202400C Oddly, while I have seen similar errors before (so at = least some access to unmapped pages was caught even before your patch), I hadn't noticed them for a while with egltri_screen... Anyway, some more experimentation shows that it doesn't happen if I skip the clear, and it still happens when doing only a clear. I'll look into what might be wrong with the clears next week. > Yeah only thing i can think of, can you get dump of various mc fault > reg after lockup ? Did you have any particular registers in mind? -- = Earthling Michel D=E4nzer | http://www.amd.com Libre software enthusiast | Debian, X and DRI developer