On Wed, 2004-05-19 at 11:25, Ian Romanick wrote: > Jon Smirl wrote: > > --- Alan Cox <[EMAIL PROTECTED]> wrote: > > > >>s/OpenGL/Some drawing library/ - providing its using the kernel > >>interfaces we don't care what. (eg the bogl console driver is very > >>small, the opengl one would probably be rather larger and nicer) > > > > I wasn't thinking that the kernel interface was standardized. For example DRM > > has some common IOCTLs and then hundreds of per chipset ones. There is no > > standard bitblt or draw char IOCTL. > > IMO, this is a long standing problem with the DRM. The main issue is > that there's only one version number associated with each DRM module. > What's needed is a device independent version and a device dependent > version. In a sense, it needs something like an extension mechanism. > Right now, some drivers support a vblank wait ioctl and some don't. The > ones that do support it, support it the same way. > > If we could extend the DRM API in a device independent manner, we could > solve some of this. When I thought about this in the past, I came up > with two ways to do it. > > 1. Add a device independent version. Device independent code could be > written that would test the version number the same way device dependent > code does today. The drawback is that in order to advertise version X.N > functionality, you also have to adverteise version [1.1, 1.N-1] > functionality. Some hardware / drivers may not want to / be able to do > that. > > 2. Add an "extension" query ioctl. Give each piece of functionality > (i.e., all the related vblank functions) a unique number. Drivers would > make a query like, "Is extension 5 supported?" If that ioctl returns > true, then the driver could use that functionality. The disadvantage of > this method is that it increases the number of ioctl calls that need to > be made. Since the set of supported extensions can be tracked in the > DRM with a bit string, the additional code size should be trivial. > > Thoughts?
We already have a device independent version. What I put in was that the X Server can request a DRM device-independent and device-dependent interface version. The DRM changes its behavior accordingly (busid handling was the first change). Returns EINVAL if unsuccessful, and returns the actual version numbers of the DRM DI/DD interface, either way. Request -1.-1 version to just get the version number of an interface without changing anything. This was part of working to allow removal of old DRM code/features, which I've been completey distracted from. -- Eric Anholt [EMAIL PROTECTED] http://people.freebsd.org/~anholt/ [EMAIL PROTECTED] ------------------------------------------------------- This SF.Net email is sponsored by: SourceForge.net Broadband Sign-up now for SourceForge Broadband and get the fastest 6.0/768 connection for only $19.95/mo for the first 3 months! http://ads.osdn.com/?ad_id=2562&alloc_id=6184&op=click -- _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
