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AMD's open GPU documentation site
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FINALLY!
Posted Feb 12, 2008 16:35 UTC (Tue) by flewellyn (subscriber, #5047) [Link]
Alright, NOW we finally have documentation for recent ATI chipsets. I am not a driver programmer, so I don't know if this is everything needed to make a good free driver, but hopefully it's useful.
FINALLY!
Posted Feb 12, 2008 16:43 UTC (Tue) by hathawsh (subscriber, #11289) [Link]
Goodbye, Nvidia. (Unless of course you also release docs... but you better do it soon because the exodus is coming.)
FINALLY!
Posted Feb 12, 2008 17:10 UTC (Tue) by Felix.Braun (subscriber, #3032) [Link]
Could anybody knowledgable enough please verify whether the documents provided finally include information concerning the 3D-acceleration parts of these chips? That would be seriously cool!
Old news
Posted Feb 12, 2008 17:35 UTC (Tue) by kmike (guest, #5260) [Link]
These docs were already posted more than a month ago here: http://www.x.org/docs/AMD/ And no, these are no 3D docs, just basic control registers and modesetting. I guess the news here is that AMD made a special site for them.
Old news
Posted Feb 12, 2008 17:47 UTC (Tue) by flewellyn (subscriber, #5047) [Link]
Well, that's disappointing. I suppose we'll have to wait some more for documentation enough to make a full driver, eh?
Surely they have their own documentation for their own driver writers, though!
Old news
Posted Feb 12, 2008 18:45 UTC (Tue) by vmole (subscriber, #111) [Link]
Don't count on it. The existing "documentation" might well be an overview ("here's the new stuff since R300") and lots of e-mails and phone calls.
You can be sure they don't
Posted Feb 12, 2008 21:41 UTC (Tue) by khim (subscriber, #9252) [Link]
I'm pretty sure that's bunch of presentations, architecture overviews plus some e-mails. In-house driver writers can always just ask guys who develop hardware about details...
You can be sure they don't
Posted Feb 12, 2008 21:45 UTC (Tue) by flewellyn (subscriber, #5047) [Link]
Well, that's...unsettling.
You can be sure they don't
Posted Feb 13, 2008 15:13 UTC (Wed) by liljencrantz (subscriber, #28458) [Link]
It would explain the quality level of the ATI drivers, though.
You can be sure they don't
Posted Feb 14, 2008 17:56 UTC (Thu) by iabervon (subscriber, #722) [Link]
It's not unusual that the knowledge about how hardware works is codified in QA procedures, designer knowledge, and a lot of notes that don't form a coherent document. The economics of this particular market is that there really isn't time to write up documents that will explain how to use the hardware to an outsider before the device needs to have drivers already written and available to the public, and there's been little reason to write up such documents after the driver is written. Furthermore, there are a lot of corner cases, where the vendor driver doesn't try doing something, and the hardware designers didn't except the driver writers to try it, and so nobody's bothered to figure out if it would cause problems or not. They avoid trying to evaluate a combinatorial explosion of unknown interactions by only checking the ones that people are interested in, which is a big help in getting work done in a reasonable amount of time, but only if the process is interactive. (And it's likely that a different implementation of high-level 3D operations on the low-level units they have would hit different combinations than the ones that the designers have verified to work together)
You can be sure they don't
Posted Feb 14, 2008 19:38 UTC (Thu) by flewellyn (subscriber, #5047) [Link]
From the sound of things, they'd benefit hugely from an open development model. :-)
You can be sure they don't
Posted Feb 13, 2008 10:09 UTC (Wed) by forthy (guest, #1525) [Link]
I'm not sure if you can develop such a complex piece of hardware with such a lousy procedure. I'm developing hardware, simpler one than ATI graphics cards, and we certainly have internal documentation, most of them on a Wiki. We also have people who write documentation for people outside the company, they take the information from the Wiki, polish it up, and delete those parts of the interface that's only used for debugging ;-). And even our largest projects have only a few people involved.
Speaking for me: Even when I do all the things as a one-man show, i.e. designing the hardware, creating the address map and the registers, and writing the software, I'm still writing documentation as well. I don't want to dig into several Verilog files, documentation should not only be inside those files. I sometimes even use literate programming style to get documentation and source together, where it's needed.
AMD's open GPU documentation site
Posted Feb 12, 2008 17:08 UTC (Tue) by kraftcheck (subscriber, #35072) [Link]
These documents appear to contain only the basic control functionality. They don't contain anything about acceleration (not even 2D). I'm sure these docs will be useful, but quite a bit more is required for a complete OS driver.
AMD's open GPU documentation site
Posted Feb 12, 2008 17:40 UTC (Tue) by jwb (subscriber, #15467) [Link]
It took Intel a year and a half to produce documentation for the G965. Perhaps it will take AMD about the same amount of time.
AMD's open GPU documentation site
Posted Feb 12, 2008 20:05 UTC (Tue) by tajyrink (subscriber, #2750) [Link]
The rumor is specs for 2D acceleration and basic 3D should be just around the corner (really). They are aiming for "basic" (read: Compiz, Nexuiz etc.) 3D support sooner and then eventually a kicking open source 3D support via the emerging Gallium architecture. XAA and EXA 2D accelerations are now already working on R500, R600 is the one that's a really different beast. Best source for news seems to be http://www.radeonhd.org/ that is related to the Phoronix site.
AMD's open GPU documentation site
Posted Feb 13, 2008 17:26 UTC (Wed) by jmayer (subscriber, #595) [Link]
> XAA and EXA 2D accelerations are now already working on R500 Well, not really or not in the way most readers would expect: They have been implemented in the driver, so yes, they run, but currently run without any hardware support. This means that anyone running XAA or EXA get *less* performance than someone running just ShadowFB. See http://lists.opensuse.org/radeonhd/2008-01/msg00233.html for details.
AMD's open GPU documentation site
Posted Feb 23, 2008 17:50 UTC (Sat) by daenzer (subscriber, #7050) [Link]
Where did you read 'without any hardware support' there? Both XAA and EXA would be totally pointless in that case of course. The benchmarks where they're slower than ShadowFB exercise paths that the driver doesn't accelerate yet (mostly related to the RENDER extension - that can be fixed now that AMD released 3D documentation), so the acceleration architectures have to pay a price for trying to accelerate things instead of just doing them with the CPU in system memory in the first place. It shouldn't be hard to find other benchmarks where hardware acceleration is much faster than ShadowFB. Which of the options works best in practice depends on the usage pattern, so everybody has to find out for themselves.
Time is not on their side
Posted Feb 13, 2008 9:17 UTC (Wed) by alex (subscriber, #1355) [Link]
It does seem to be that it takes a long time for the docs to get out there. At least I'm pretty confident that it's coming. However having the docs come out long after the chipset has debuted isn't going to help with design wins that want to know a open driver will be ready when the hardware ships. I still find it odd that the Dell Linux machines come with nVidia graphics because that's the most stable state of the art for the time being.