Re: [PATCH] use mutex instead of semaphore in RocketPort driver
From: Robert Hancock
Date: Tue Apr 24 2007 - 19:54:43 EST
Matthias Kaehlcke wrote:
El Tue, Apr 24, 2007 at 07:53:04PM +0200 Oliver Neukum ha dit:
Am Dienstag, 24. April 2007 19:49 schrieb Matthias Kaehlcke:
@@ -1706,7 +1706,7 @@ static int rp_write(struct tty_struct *tty,This is a bug. It is also present in the current code, but nevertheless
if (count <= 0 || rocket_paranoia_check(info, "rp_write"))
it is a bug. If you use an interruptible lock, you must be ready to deal
with interrupts, which are ignored by this code.
i fear i don't have the experience/knowledge to fix this bug, thanks
for your remark.
i'm a bit confused now about the interruptible locks, i thought using
them means that the process will be waked up when receiving a
signal. what role are playing interrupts when using interruptible locks?
You are correct, interrupts aren't involved. However if the wait is
interrupted by a signal, mutex_lock_interruptible will return a nonzero
return code which needs to be checked for (and likely -ERESTARTSYS or
-EINTR returned), otherwise the code will blindly continue as though it
has locked the mutex even though it has not.
Robert Hancock Saskatoon, SK, Canada
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