I've started investigating in the timer event problem and I think I have some weird problem with my platform drivers(I hope, so it's not a EDK2 bug).
If I create a timer that runs every 100ms which does nothing but a stall(1), the thread mode code stops after some random time(usually in edk2 shell so I guess it's a race condition which needs some cpu load). When threadmode code is stopped the timer continues getting called and even if I stop the timer afterwards(with CloseEvent) it keeps being stopped. Is there a way to get the threadmode context from inside a timer callback? This way I could read the PC to check what's going on. Michael On Wed, Nov 11, 2015 at 8:10 PM, Kinney, Michael D < [email protected]> wrote: > Michael, > > A periodic event timer at 30 times a second should not cause pauses > forever, unless the action you are performing in the event notification > function takes more than 1/30 of a second to complete. You should be able > to just add a periodic event handler that does nothing, so you can measure > what the overhead is. > > Another option is to use the performance counter in the TimerLib each time > a Blt() is called (GetPerformanceCounterProperties() and > GetPerformanceCounter()). When Blt() is called frequently, the amount of > time since last vsync will have elapsed, and you can go the vsync action > within the Blt() call. If you also set a one shot timer event, so if the > last call to Blt() did not do a vsync and there are no more Blt() calls, > 1/30th of a second later, the vsync action can be done. Every time Blt() > is called, the one shot timer can be re-armed. This way, the one shot > timer event is not actually executed very often. > > Mike > > >-----Original Message----- > >From: edk2-devel [mailto:[email protected]] On Behalf Of > Michael Zimmermann > >Sent: Wednesday, November 11, 2015 12:32 AM > >To: [email protected] > >Subject: [edk2] EFI GOP with manual vsync trigger > > > >Hi, > > > >my Graphics HW uses a manual vsync trigger. That means that after drawing > >to the framebuffer I need to manually trigger vsync(you can compare it to > >switching between double buffers). > > > >The problem is that UEFI's GraphicsOutputProtocol(GOP) doesn't take care > of > >HW that needs a flush. > >While issuing the trigger after every Blt Operation works, this obviously > >causes extremely slow rendering for applications like the Shell which call > >Blt very often(like for every character). > > > >Also I can't use a timer to set the trigger(like 30times a second) because > >it takes too much time and the Timer Interrupt ends up consuming too much > >time and the "normal" code gets paused forever. > > > >Do you have any other ideas how to handle this? > > > >Thx > >Michael > >_______________________________________________ > >edk2-devel mailing list > >[email protected] > >https://lists.01.org/mailman/listinfo/edk2-devel > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
