Messages in this thread | | | Date | Tue, 21 Oct 2014 15:42:00 -0400 | From | Peter Hurley <> | Subject | Re: [PATCH] tty: serial: msm: Fix lock init issue with earlycon |
| |
On 10/20/2014 06:20 PM, Stephen Boyd wrote: > On 10/20, Stephen Boyd wrote: >> On 10/20, Peter Hurley wrote: >>> >>> FWIW, __msm_console_write() is a deadlock-waiting-to_happen since it does >>> not disable interrupts with spin_lock_irqsave(). >>> >> >> Yeah we should fix that. As far as I can tell we've never used >> the irqsave variant of the lock in the console path. Did this >> become necessary at some point since this driver was introduced? >> I'm wondering how many stable trees need the fix. > > Actually I don't see this case. It looks like the console is > always called in call_console_drivers() with irqs saved and > disabled via the logbuf_lock in console_cont_flush() or > console_unlock().
Thanks for bringing that to my attention.
That looks like a vestige of the initial transition away from BKL. I might look into just disabling preemption; even that might not really be necessary.
Regards, Peter Hurley
| |