Re: r200 multiple app lockups, possible explanation

[Michel <mi...@da...>]

On Fri, 2004-05-28 at 19:22 +0200, Roland Scheidegger wrote:
> So, when I updated radeon_maos_arrays.c and compiled that (btw really 
> brave souls can try it out, just define RADEON_OLD_PACKETS to 0 in 
> radeon_context.h and RADEON_MAOS_VERTS to 0 in radeon_maos.c, that 
> codepath was only enabled in april 2002 for 9 days and probably caused a 
> 15% slowdown according to that mail, 
> http://marc.theaimsgroup.com/?l=dri-devel&m=101836484905209&w=2, so the 
> question of course is would implementing the maos_verts path for r200 
> driver result in a 15% speedup?), I came across some stuff which seems 
> like it could be related to the r200 lockups.
> The radeon driver today still uses RADEON_OLD_PACKETS 1, the r200 driver 
> also had the same variable (R200_OLD_PACKETS) but set to 0 (and not 
> implemented the other path, some hours ago I've removed the unused 
> macro). However, the reason old packets are used for radeon is according 
> to the cvs entry (3 jul 2002) this: "Use old packets (aos+vertex data in 
> one packet) to avoid problems when buffer wraps between the two new 
> packets.  Reported by Michael a while ago...". This refers to this mail, 
> http://marc.theaimsgroup.com/?l=dri-devel&m=102395055325248&w=2.
> 
> But if I look at that code, the r200 driver seems to implement it in 
> exactly the same way as the radeon driver (if RADEON_OLD_PACKETS is not 
> set). So could this be the reason why a simple glxgears + quakeIII still 
> locks up the chip?

I can't really say either way; sounds plausible though. Good luck
digging deeper. :)

Have you tried Nicolai's watchdog and engine reset patches to see if
they make a difference towards recovering from the lockup?


-- 
Earthling Michel Dänzer      |     Debian (powerpc), X and DRI developer
Libre software enthusiast    |   http://svcs.affero.net/rm.php?r=daenzer