2009/12/25 Rafał Miłecki <zaj...@gmail.com>: > W dniu 24 grudnia 2009 23:19 użytkownik Luca Tettamanti > <kronos...@gmail.com> napisał: >> 2009/12/24 Rafał Miłecki <zaj...@gmail.com>: >>> W dniu 24 grudnia 2009 17:32 użytkownik Luca Tettamanti >>> <kronos...@gmail.com> napisał: >>>> I think it would be safer to execute that code in the IH (or in a tasklet, >>>> which is guaranteed to run after the handler); the only problem I see is >>>> that atom_execute_table allocates some memory (ws? workspace?), but the >>>> GFP flag can be easily adjusted; the rest of the ops seem safe. >>>> What do you think? >>> >>> Thank you for commenting. Indeed we have problems with engine >>> reclocking not happening right after VBLANK. >> >> The conversion to bh is pretty simple, and it blows up in a spectacular way >> :-) >> Aside from the locking (mutex) which has to be reworked, the show >> stopper is atom_op_delay, which wants to schedule. >> In my BIOS the biggest delays in SetEngineClock are 200us, so it would >> be possible to use udelay; not sure if the msec path could use the >> same treatment. > > I've read LDD3 ch07.pdf again and I can see why I've chosen workqueue. > > AFAIU tasklets are similar to timers but without execution time as > param. It seems to be something like "execute it really soon".
Not really, they're part of "other half" of the interrupt processing; pending tasklets run in softirq, and they are guaranteed to be executed after processing the hw interrupt. > That's > fine but the problem is we can not sleep in tasklet handler (handlers > has to be atomic). As you noticed we need to sleep in reclocking > (AtomBIOS command does). Well, I've converted atom_op_delay to busy loop and the tasket does work. Locking with CP is missing though. > I think solution may be sleeping in radeon_pm_idle_work_handler in > place where we currently set: "rdev->pm.vblank_callback = true;". We > would sleep and ask IRQ code to wake us on VBLANK. Maybe this would be > fast enough solution? Or do you have other, better idea? Just keep in > mind that we do sleep in radeon_set_engine_clock. I don't think it would change much in term of latency. I'll follow the other thread ;-) Luca ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
