From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 18 Jan 2004 23:20:53 +0100 To: Michel =?iso-8859-1?Q?D=E4nzer?= Cc: Sven Luther , linuxppc-dev list Subject: Re: multiple separate pci bridges ... Message-ID: <20040118222053.GA11651@iliana> References: <20040118144412.GA6897@iliana> <1074443601.9704.164.camel@thor.asgaard.local> <20040118172838.GA8785@iliana> <1074450283.9700.200.camel@thor.asgaard.local> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: <1074450283.9700.200.camel@thor.asgaard.local> From: Sven Luther Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Sun, Jan 18, 2004 at 07:24:44PM +0100, Michel Dänzer wrote: > On Sun, 2004-01-18 at 18:28, Sven Luther wrote: > > On Sun, Jan 18, 2004 at 05:33:21PM +0100, Michel Dänzer wrote: > > > On Sun, 2004-01-18 at 15:44, Sven Luther wrote: > > > > > > > > > The freeze happens when i first launch glxinfo, or when i first start > > > > moving a window around (using a debian/unstable default gnome desktop). > > > > I don't remember well, but i think it would also freeze when let running > > > > for a time, but i am not sure. > > It would be quite interesting to know, see below. But then, maybe it has something to do with the GL screensaver or something such. The problem is that i have this box on the analog entry of my dual entry monitor, and mostly work on the box connected to the DVI connector, so it usually died while i was not looking. > > > > The box is still available trough ssh, but killing the X server > > > > doesn't restore the fbdev console, and freeze the box. > > > > > > Sounds like a typical chip lockup, possibly caused by the chip not > > > reading from the CP ring what we're writing to it. > > > > Well, not sure. Compared to the pegasos 1 situation, where nothing > > showed up on the screen, except the hardware cursor, Things seem to work > > out fine at first, and only certain operation make it happen. The gdm > > prompt comes up, you can log in, then once logged in, you can open a > > gnome-terminal, and even do some stuff. Once you try moving the window > > though, it starts moving, but then quickly freezes. > > Because the RENDER extension isn't accelerated, that might be the first > time the ring is heavily used. Yep. Altough this problem doesn't occur for the Radeon 7500 on the same board. I believe it may be triggered by some problem which is present in the R200 code path, and which is present in the R100 software T&L (since i think the 7000 and 7200 lack a T&L engine). > It might also occur when the ring wraps around; whether or not it also > happens when the server is idling would give a hint about this, or even > better instrumenting the wraparound handling code in the DRM. Ok, i will look into this and do some experiments. What is the size of the ring anyway ? 4K or something such ? > > I believe there is maybe more a problem with the CPU and the graphic > > chip being in disacord over the size of the CP ring. > > I'd expect problems everywhere if that code wasn't correct. Mmm. > > Come to think of it, i have three negative tries (Radeon 7000, 7200 and > > 9200SE) and one positive (Radeon 7500), or at least claimed such, the > > glxgears numbers obtained with the Radeon 7500 where not all that high > > (maybe 300 or so), but still higher than the software only numbers i > > obtain on my box with Radeon 9200 SE. > > PCI GART isn't very fast in general, it's even mysteriously slow on some > systems, see the dri-devel list archives. Ok. There is no other chance anyway, since there is no true AGP bus on these boxes. The nortbridge used is a communication controller after all. > > Also, the Radeon 9200 SE has only 64bit memory interface. I don't know > > about 7000 and 7200, but maybe this is also the case for them, while the > > 7500 could have 128bit memory interface ? Not sure, will investigate. > > I doubt that matters. I doubt it too. But then, if the chip measures data in multiples of the memory words or something such, it may have an influence. Friendly, Sven Luther ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/