Hi,
Recently, trying to fix saa7134 suspend/resume problems I found that there
is a race between IRQ handler and .suspend , and that I cant let driver access the device
while its in D3 since it can lock up some systems.
Now I am looking to fix those issues in two drivers that have my .suspend/.resume routines.
the saa7134 capture chip and dmfe, the davicom network driver.
Looking through the dmfe code, I noticed yet another possible race.
A race between the .suspend, and a timer that serves both as a watchdog, and link state detector.
Again I need to prevent it from running during the suspend/resume, but how?
I can use del_timer in .suspend, and mod_timer in .resume, but that doesn't protect against
race with already running timer.
I can use del_timer_sync, but it states that it is useless if timer re-enables itself, and I agree with that.
In dmfe case the timer does re-enable itself.
I can put checks in the timer for ->insuspend, and don't re enable it if set,
but that opens a new can of worms with memory barriers, etc...
So please tell me how properly to do that.
By the way, this problem, together with synchronize_irq it very generic, since most drivers
have and irq handler, and a timeout timer.
Best regards,
Maxim Levitsky
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
