W dniu 12 listopada 2009 14:46 użytkownik Jerome Glisse <gli...@freedesktop.org> napisał: > On Wed, 2009-11-11 at 21:51 +0100, Rafał Miłecki wrote: >> I attach my very hackish patch to downclock GPU. >> >> Could someone tell me please, why first method in this patch works >> while second locks up my GPU? >> >> I've run >> cat radeon_pm_info >> 100x times with first method. No problem. Second method fails on every >> try, checked it with 5 reboots. >> >> Jerome told sth about engine idle, but does it really matter? Why then >> first method works fine every time? I don't really believe that is the >> real issue. > > > Does calling radeon_pm_reclock 2 times in a row leads to lockup too ? > radeon_pm_reclock((unsigned long)rdev); > radeon_pm_reclock((unsigned long)rdev);
No, radeon_pm_reclock is still safe even if I call it 4 times in a row. Tried that 20 with 2 calls in row and 20 times with 4 calls in row. > If so then it's most likely because with the timer engine didn't had > enough time to settle after reclock. Sadly atombios seems to be too > much conservative about that so we might need to find how to figure > if engine is settle at the new frequency. I've tried hacks like: radeon_set_engine_clock(rdev, 30000); /* 300'000 kHz */ for (i=0; i<9999999; ++i); for (i=0; i<9999999; ++i); for (i=0; i<9999999; ++i); for (i=0; i<9999999; ++i); and radeon_set_engine_clock(rdev, 30000); /* 300'000 kHz */ mdelay(5); and radeon_set_engine_clock(rdev, 30000); /* 300'000 kHz */ mdelay(100); but this didn't help. Why actually ending timer's thread before engine settling may cause crash? Does AtomBIOS try to touch something that dies with end of timer's thread? Why my workarounds don't work? > The need for idle comes from AMD documentation and it makes sense, > you don't want to change clock while the GPU is doing somethings. -- Rafał ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
