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authorRodolfo Giometti <giometti@linux.it>2009-11-11 14:26:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-11-12 07:26:01 -0800
commit276b282e904f690dc930f9bc946110651f297669 (patch)
tree7e50db4cee555f6044bd389452269d3c0fe45ed6 /drivers/pps/kapi.c
parentcbf83cc5a29dba480cf1ba1c5e3417a0d4a31410 (diff)
downloadlwn-276b282e904f690dc930f9bc946110651f297669.tar.gz
lwn-276b282e904f690dc930f9bc946110651f297669.zip
pps: events reporting fix up
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>
Diffstat (limited to 'drivers/pps/kapi.c')
-rw-r--r--drivers/pps/kapi.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/pps/kapi.c b/drivers/pps/kapi.c
index 35a0b192d768..2d414e23d390 100644
--- a/drivers/pps/kapi.c
+++ b/drivers/pps/kapi.c
@@ -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);