lkml.org 
[lkml]   [2016]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: v4.4.12-rt20 build: 0 failures 5 warnings (v4.4.12-rt20)
* 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

\
 
 \ /
  Last update: 2016-07-29 18:01    [W:0.039 / U:1.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site