Messages in this thread | | | Date | Fri, 29 Jul 2016 17:23:58 +0200 | From | Sebastian Andrzej Siewior <> | Subject | Re: v4.4.12-rt20 build: 0 failures 5 warnings (v4.4.12-rt20) |
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* Arnd Bergmann | 2016-07-15 21:48:55 [+0200]:
>I also notice that your "tty: serial: 8250: don't take the trylock >during oops" patch would apply on the pl011 driver as well.
That one. That is something I am not really sure about in the long run. On -RT we can't try_lock() with IRQs off and that is why I removed it. You could do the same with pl011 but you are screwed anyway because clk_enable() will take a sleeping lock and that is a no no.
So you could stay with the try_lock because it does not solve anything. In the long run I though about a console flag which denotes the console as RT-IRQ save which is the case for 8250 but not for pl011 (due to clk_enable()) so should not get on -RT into this case where it matters.
On the other hand if you oops on !RT+UP in your uart driver while holding the lock then the try_lock will fail resulting in a lockdep splat (because try_lock should not fail on UP). So might want take it as a procation in that case :)
>Sure, that always works, it's just a bit ugly since the flags word >should never be zero when it gets written back to the hardware irq >state, at least in portable code.
yes :)
>Maybe something like the version below?
sure.
Sebastian
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