Messages in this thread | | | Date | Thu, 3 Mar 2011 17:12:12 +0800 | Subject | Re: (WARNING) possible deadlock in del_timer_sync, called from fbcon_del_cursor_timer | From | Yong Zhang <> |
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On Thu, Mar 3, 2011 at 2:12 AM, Steven Rostedt <rostedt@goodmis.org> wrote: > On Mon, Feb 28, 2011 at 03:41:07PM +0100, Clemens Ladisch wrote: >> While using the FB console, I tried to change the console log level >> with SysRq, and got this warning that del_timer_sync() is used in >> an interrupt handler: > > Ug, del_timer_sync() can be called from interrupt context: > > printk -> vt_console_print -> hide_cursor -> fbcon_cursor > -> fbcon_del_cursor_time -> del_timer_sync() > > printk is allowed to be called from interrupt context. This is indeed a > true bug.
Yeah.
And more explanation for that WARN_ON() :)
run_timer_softirq(SOFTIRQ context) cursor_timer_handler() Interrupt comes in(IRQ context) ... del_timer_sync() deadlock
So fbcon guys: Could above situation happen?
Cc'ing people from: ./scripts/get_maintainer.pl -f drivers/video/console/fbcon.c
Thanks, Yong
-- Only stand for myself
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