--- Thomas Hellström <[EMAIL PROTECTED]> wrote: > Hi, list! > > With display cards that have more and more hardware on them, > (TV-capture, mpeg decoders) etc. that can work independently of > oneanother, but share the same DMA engine I've find the need for more > than one hardware lock. I've done a simple implementation for the mpeg > decoder of the via driver, but that one doesn't cover the DMA case. The > question arises "Why should I need to wait for DMA quiescent to check > whether the decoder is done with a frame, if there is no decoder data in > > any of the pending DMA buffers"? > > In the VIA / Unichrome case alone there is a need for even more such > locks for different parts of the chip if one were to make a clean > implementation of drivers for all features that are on the chip. > > My idea would be to extend drm with options for multiple locks, and I > suspect not only VIA cards could benefit from this. I was thinking of. > > 1. A separate sarea to contain these locks, to avoid messing up the > current sarea with binary incompatibilities as a consequence. > 2. Other kernel modules should be able to take and release these locks. > (V4L for example). > 3. Each DMA buffer is marked (or in the VIA case, each submission to the > > ring-buffer is marked) wether it accesses the resource that is protected > There is a problem with A "client" being able to lock/unlock resources it may/may not be using. It's important that Client's arn't able to DOS the system by submitting junk cmds /wo setting the right locs for that junk.
> by a certain lock. > 4. A resource will become available to a client when the client has > taken the lock and there are no pending DMA buffers / parts of buffers > that are marked touching this resource. > 5. The client is responsible for reinitializing the resource once the > lock is taken. > > These are just initial thoughts. Is there a mechanism for this in DRM > today or could > it be done in a better way? > > /Thomas > > > > > > > > > ------------------------------------------------------- > This SF.Net email is sponsored by: > Sybase ASE Linux Express Edition - download now for FREE > LinuxWorld Reader's Choice Award Winner for best database on Linux. > http://ads.osdn.com/?ad_id=5588&alloc_id=12065&op=click > -- > _______________________________________________ > Dri-devel mailing list > [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/dri-devel > __________________________________ Do you Yahoo!? Y! Messenger - Communicate in real time. Download now. http://messenger.yahoo.com ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_id=5588&alloc_id=12065&op=click -- _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
