pps: events reporting fix up
Rodolfo Giometti [Wed, 11 Nov 2009 22:26:54 +0000 (14:26 -0800)]
PPS events must be recorded according to PPS's mode settings.

If a process asks for (i.e.) capture-assert events only, when the PPS
client calls the pps_event() function to save the current PPS event, we
should verify the event type and then discard unwanted ones.

Also, without this patch userland processes waiting for a specific PPS
event (assert or clear but not both) may be awakened at wrong time.

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Tested-by: William S. Brasher <billb958@door.net>
Tested-by: Reg Clemens <clemens@dwf.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/pps/kapi.c

index 35a0b19..2d414e2 100644 (file)
@@ -271,6 +271,7 @@ void pps_event(int source, struct pps_ktime *ts, int event, void *data)
 {
        struct pps_device *pps;
        unsigned long flags;
+       int captured = 0;
 
        if ((event & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR)) == 0) {
                printk(KERN_ERR "pps: unknown event (%x) for source %d\n",
@@ -293,7 +294,8 @@ void pps_event(int source, struct pps_ktime *ts, int event, void *data)
 
        /* Check the event */
        pps->current_mode = pps->params.mode;
-       if (event & PPS_CAPTUREASSERT) {
+       if ((event & PPS_CAPTUREASSERT) &
+                       (pps->params.mode & PPS_CAPTUREASSERT)) {
                /* We have to add an offset? */
                if (pps->params.mode & PPS_OFFSETASSERT)
                        pps_add_offset(ts, &pps->params.assert_off_tu);
@@ -303,8 +305,11 @@ void pps_event(int source, struct pps_ktime *ts, int event, void *data)
                pps->assert_sequence++;
                pr_debug("capture assert seq #%u for source %d\n",
                        pps->assert_sequence, source);
+
+               captured = ~0;
        }
-       if (event & PPS_CAPTURECLEAR) {
+       if ((event & PPS_CAPTURECLEAR) &
+                       (pps->params.mode & PPS_CAPTURECLEAR)) {
                /* We have to add an offset? */
                if (pps->params.mode & PPS_OFFSETCLEAR)
                        pps_add_offset(ts, &pps->params.clear_off_tu);
@@ -314,12 +319,17 @@ void pps_event(int source, struct pps_ktime *ts, int event, void *data)
                pps->clear_sequence++;
                pr_debug("capture clear seq #%u for source %d\n",
                        pps->clear_sequence, source);
+
+               captured = ~0;
        }
 
-       pps->go = ~0;
-       wake_up_interruptible(&pps->queue);
+       /* Wake up iif captured somthing */
+       if (captured) {
+               pps->go = ~0;
+               wake_up_interruptible(&pps->queue);
 
-       kill_fasync(&pps->async_queue, SIGIO, POLL_IN);
+               kill_fasync(&pps->async_queue, SIGIO, POLL_IN);
+       }
 
        spin_unlock_irqrestore(&pps->lock, flags);