From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ondrej Zary Subject: Re: nouveau broken on Riva TNT2 in 5.9.0-rc8: GPU not supported on big-endian Date: Wed, 28 Oct 2020 21:15:32 +0100 Message-ID: <202010282115.32811.linux@zary.sk> References: <202010092326.20482.linux@zary.sk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: nouveau-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Sender: "Nouveau" To: Karol Herbst Cc: nouveau , dri-devel , Ben Skeggs , LKML List-Id: nouveau.vger.kernel.org On Saturday 10 October 2020 02:02:42 Karol Herbst wrote: > On Sat, Oct 10, 2020 at 12:23 AM Ilia Mirkin wrote: > > > > On Fri, Oct 9, 2020 at 5:54 PM Karol Herbst wrote: > > > > > > On Fri, Oct 9, 2020 at 11:35 PM Ondrej Zary wrote: > > > > > > > > Hello, > > > > I'm testing 5.9.0-rc8 and found that Riva TNT2 stopped working: > > > > [ 0.000000] Linux version 5.9.0-rc8+ (zary@gsql) (gcc (Debian 8.3.0-6) 8.3.0, GNU ld (GNU Binutils for Debian) 2.31.1) #326 SMP Fri Oct 9 22:31:40 CEST 2020 > > > > ... > > > > [ 14.771464] nouveau 0000:01:00.0: GPU not supported on big-endian > > > > [ 14.771782] nouveau: probe of 0000:01:00.0 failed with error -38 > > > > > > > > big-endian? WTF? The machine is x86. > > > > > > > > > > mhh, we reworked the endianess checks a bit and apparently that broke > > > something... I will give it some thoughts, but could you be so kind > > > and create an mmiotrace under 5.9 with nouveau? You won't need to > > > start X or anything while doing it. Just enable the trace and modprobe > > > nouveau and collect the trace. > > > > Looks like nvkm_device_endianness unconditionally reads out 0x4. I > > don't think that reg is there pre-NV11. At least NV4, NV5, NV10 and > > maybe NV15 (which is logically pre-NV11) don't support big-endian > > mode. Not sure about NV1A, which was the IGP of the series and IIRC > > logically pre-NV11 as well (but clearly could only be used with x86 > > chips, since it was part of the motherboard). > > > > Aha, it's documented in rnndb: > > > > https://github.com/envytools/envytools/blob/master/rnndb/bus/pmc.xml > > > > > > ohh, I should have checked there.. yeah, will write a fix for it then. > Before my patch we just always tried to switch it, but never threw an > error. Any progress with the patch? -- Ondrej Zary