Hello all,
I hope this is the correct list for posting this question. If not, please let
me know.
I am a Linux newbie writing a device driver for a proprietary board. I am
experiencing problems (system hard hangs) when my driver calls
interruptible_sleep_on_timeout. I have combed through the archives of this
list and have seen indications of problems in the past with this routine. I
don't know if what I am experiencing is due to a bug or a programmer error on
my part. I am currently running Red Hat 7.3 (Linux 2.4.18-3) on an Intel
Pentium III (i686). Originally I thought I was experiencing problems with
interrupt handling. My driver now does a request_irq, but does not enable it
on the hardware. Nor does it issue any commands to the board to generate an
interrupt. Thus, I would expect the interruptible_sleep_on_timeout to simply
. . . time out! (I wish I could be so lucky!!) What follows are code snips:
global driver data:
static wait_queue_head_t RcvIntrcvQ;
in my open routine:
status = request_irq(pslState->irq_line,&pslengrave_intr,
SA_INTERRUPT | SA_SHIRQ, "pslengrave", (void *)pslState);
pslState->RcvIntrcvQp = &RcvIntrcvQ;
init_waitqueue_head (pslState->RcvIntrcvQp);
/* EnableReceiverInterrupt(pslState);*/
in my ISR (which I don't expect to be called since I do not enable interrupt):
/* Receive interrupt */
if (USER_INTERRUPTING(pslState))
{
ResetReceiverInterrupt(pslState);
pslState->numRcvIntrs++;
wake_up_interruptible(pslState->RcvIntrcvQp);
}
in a routine which will eventually initiate a command to the board:
(Note the writel is currently commented out. If this was included, it would
cause the hardware to interrupt).
/* writel(Data, HardwareAddress);*/
RcvTimeLeft = interruptible_sleep_on_timeout (pslState->RcvIntrcvQp,1*HZ);
if (RcvTimeLeft)
{
if (DebugMode) printk (KERN_INFO "Rcv intr received.\n");
}
else
{
printk (KERN_INFO "Rcv intr TIMEOUT.\n");
DumpEngraverStatus(pslState);
ReceiverTimeOut = 1;
}
If I comment out the call to interruptible_sleep_on_timeout, I experience no
problems. However, if this call is left in as shown above, the system
completely hangs: the clock quits ticking, I have no keyboard, mouse, etc.
In addition, the keyboard lights for Caps Lock and Scroll lock begin
blinking. I greped through the Linux source code, but could not find
anything pertaining to LEDs, blink, etc that looked like it had to do with
this.
Any ideas, comments, suggestions?
Thanks in advance!
Kathy
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