Messages in this thread | | | Subject | Re: [PATCH 1/3] Input: sysrq - drop tty argument from sysrq ops handlers | From | Benjamin Herrenschmidt <> | Date | Wed, 04 Aug 2010 18:33:50 +1000 |
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On Wed, 2010-08-04 at 00:59 -0700, Dmitry Torokhov wrote: > Noone is using tty argument so let's get rid of it.
While talking about sysrq...
I noticed that serial drivers call sysrq with the uart lock held.
I've seen deadlocks caused by that, for example, when entering the debugger, it waits forever for a CPU which is itself waiting on the UART lock.
I have a patch to drop the lock in serial_core.h, I'll post that tomorrow hopefully, just checking if there's any objection there ? The serial drivers might need to be audited a bit to make sure they cope with the lock being dropped and re-acquired around the sysrq call.
Cheers, Ben.
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