Messages in this thread | | | Date | Mon, 10 Nov 2008 18:47:23 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: [Bug #11875] radeonfb lockup in .28-rc (bisected) |
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On Tue, 11 Nov 2008, Benjamin Herrenschmidt wrote: > > In any case, I doesn't seem to be directly related to those radeonfb > changes, though a clash with X like that is indeed more likely to > actually happen if radeonfb relies more heavily on acceleration.
Just a silly question, without actually looking at the code - since you now do acceleration in radeonfb, do you wait for everything to drain before you switch consoles?
There could be races that depend on timing, where perhaps X is unhappy about being entered with the acceleration engine busy, or conversely the radeonfb code is unhappy about perhaps some still-in-progress X thing that hasn't been synchronously waited for..
Before, radeonfb_imageblit() would always end up doing a "radeon_engine_idle()", so in practice, I think just about any fbcon access ended up idling the engine. Now, we can probably do a lot more without syncronizing - maybe there's insufficient synchronization at the switch-over from X to text-mode or vice versa?
Linus
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