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authorAndy Walls <awalls@md.metrocast.net>2011-01-16 01:02:05 (GMT)
committerMauro Carvalho Chehab <mchehab@redhat.com>2011-01-17 13:35:00 (GMT)
commitd619be27d9c82322e67ad039b775dc41163be38a (patch)
tree262c636dfaea4d6360f618f4656b7476975a93fc
parent2b410a6d1abc0e6f4b18b65cef69d12f1814497b (diff)
[media] lirc_zilog: Update IR Rx polling kthread start/stop and some printks
The IR Rx polling thread was originally a kernel_thread long ago, and had only been minimally converted to a kthread. This patch finishes that conversion by - cleaning up all the unneeded completions - destroying the kthread properly by calling kthread_stop() - changing lirc_thread() to test kthread_should_stop() just before every point where it may sleep - reorganizing the lirc_thread() function so it uses fewer lines - modifying the name of the kthread from "lirc_zilog" to "zilog-rx-i2c-N", so ps will show which kthread polls which Zilog Z8 IR unit. Also some minor tweaks were made to logging emitted by the ir_probe() function. Signed-off-by: Andy Walls <awalls@md.metrocast.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
-rw-r--r--drivers/staging/lirc/lirc_zilog.c113
1 files changed, 49 insertions, 64 deletions
diff --git a/drivers/staging/lirc/lirc_zilog.c b/drivers/staging/lirc/lirc_zilog.c
index f2e8c63..f7aa5e4 100644
--- a/drivers/staging/lirc/lirc_zilog.c
+++ b/drivers/staging/lirc/lirc_zilog.c
@@ -69,9 +69,6 @@ struct IR_rx {
struct mutex buf_lock;
/* RX polling thread data */
- struct completion *t_notify;
- struct completion *t_notify2;
- int shutdown;
struct task_struct *task;
/* RX read data */
@@ -171,12 +168,20 @@ static int add_to_buf(struct IR *ir)
* data and we have space
*/
do {
+ if (kthread_should_stop())
+ return -ENODATA;
+
/*
* Lock i2c bus for the duration. RX/TX chips interfere so
* this is worth it
*/
mutex_lock(&ir->ir_lock);
+ if (kthread_should_stop()) {
+ mutex_unlock(&ir->ir_lock);
+ return -ENODATA;
+ }
+
/*
* Send random "poll command" (?) Windows driver does this
* and it is a good point to detect chip failure.
@@ -196,6 +201,10 @@ static int add_to_buf(struct IR *ir)
"trying reset\n");
set_current_state(TASK_UNINTERRUPTIBLE);
+ if (kthread_should_stop()) {
+ mutex_unlock(&ir->ir_lock);
+ return -ENODATA;
+ }
schedule_timeout((100 * HZ + 999) / 1000);
if (ir->tx != NULL)
ir->tx->need_boot = 1;
@@ -205,6 +214,10 @@ static int add_to_buf(struct IR *ir)
continue;
}
+ if (kthread_should_stop()) {
+ mutex_unlock(&ir->ir_lock);
+ return -ENODATA;
+ }
ret = i2c_master_recv(rx->c, keybuf, sizeof(keybuf));
mutex_unlock(&ir->ir_lock);
if (ret != sizeof(keybuf)) {
@@ -255,48 +268,35 @@ static int lirc_thread(void *arg)
struct IR *ir = arg;
struct IR_rx *rx = ir->rx;
- if (rx->t_notify != NULL)
- complete(rx->t_notify);
-
dprintk("poll thread started\n");
- do {
- if (ir->open) {
- set_current_state(TASK_INTERRUPTIBLE);
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
- /*
- * This is ~113*2 + 24 + jitter (2*repeat gap +
- * code length). We use this interval as the chip
- * resets every time you poll it (bad!). This is
- * therefore just sufficient to catch all of the
- * button presses. It makes the remote much more
- * responsive. You can see the difference by
- * running irw and holding down a button. With
- * 100ms, the old polling interval, you'll notice
- * breaks in the repeat sequence corresponding to
- * lost keypresses.
- */
- schedule_timeout((260 * HZ) / 1000);
- if (rx->shutdown)
- break;
- if (!add_to_buf(ir))
- wake_up_interruptible(&rx->buf.wait_poll);
- } else {
- /* if device not opened so we can sleep half a second */
- set_current_state(TASK_INTERRUPTIBLE);
+ /* if device not opened, we can sleep half a second */
+ if (!ir->open) {
schedule_timeout(HZ/2);
+ continue;
}
- } while (!rx->shutdown);
- if (rx->t_notify2 != NULL)
- wait_for_completion(rx->t_notify2);
-
- rx->task = NULL;
- if (rx->t_notify != NULL)
- complete(rx->t_notify);
+ /*
+ * This is ~113*2 + 24 + jitter (2*repeat gap + code length).
+ * We use this interval as the chip resets every time you poll
+ * it (bad!). This is therefore just sufficient to catch all
+ * of the button presses. It makes the remote much more
+ * responsive. You can see the difference by running irw and
+ * holding down a button. With 100ms, the old polling
+ * interval, you'll notice breaks in the repeat sequence
+ * corresponding to lost keypresses.
+ */
+ schedule_timeout((260 * HZ) / 1000);
+ if (kthread_should_stop())
+ break;
+ if (!add_to_buf(ir))
+ wake_up_interruptible(&rx->buf.wait_poll);
+ }
dprintk("poll thread ended\n");
- /* FIXME - investigate if this is the proper way to shutdown a kthread*/
return 0;
}
@@ -1169,25 +1169,12 @@ static const struct file_operations lirc_fops = {
.release = close
};
-/* FIXME - investigate if this is the proper way to shutdown a kthread */
static void destroy_rx_kthread(struct IR_rx *rx)
{
- DECLARE_COMPLETION(tn);
- DECLARE_COMPLETION(tn2);
-
- if (rx == NULL)
- return;
-
/* end up polling thread */
- if (rx->task && !IS_ERR(rx->task)) {
- rx->t_notify = &tn;
- rx->t_notify2 = &tn2;
- rx->shutdown = 1;
- wake_up_process(rx->task);
- complete(&tn2);
- wait_for_completion(&tn);
- rx->t_notify = NULL;
- rx->t_notify2 = NULL;
+ if (rx != NULL && !IS_ERR_OR_NULL(rx->task)) {
+ kthread_stop(rx->task);
+ rx->task = NULL;
}
}
@@ -1290,8 +1277,8 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
else if (tx_only) /* module option */
return -ENXIO;
- zilog_info("%s: probing IR %s on %s (i2c-%d)\n",
- __func__, tx_probe ? "Tx" : "Rx", adap->name, adap->nr);
+ zilog_info("probing IR %s on %s (i2c-%d)\n",
+ tx_probe ? "Tx" : "Rx", adap->name, adap->nr);
mutex_lock(&ir_devices_lock);
@@ -1360,27 +1347,23 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
/* Proceed only if we have the required Tx and Rx clients ready to go */
if (ir->tx == NULL ||
(ir->rx == NULL && !tx_only)) {
- zilog_info("%s: probe of IR %s on %s (i2c-%d) done, waiting on "
- "IR %s\n", __func__, tx_probe ? "Tx" : "Rx",
- adap->name, adap->nr, tx_probe ? "Rx" : "Tx");
+ zilog_info("probe of IR %s on %s (i2c-%d) done. Waiting on "
+ "IR %s.\n", tx_probe ? "Tx" : "Rx", adap->name,
+ adap->nr, tx_probe ? "Rx" : "Tx");
goto out_ok;
}
/* initialise RX device */
if (ir->rx != NULL) {
- DECLARE_COMPLETION(tn);
-
/* try to fire up polling thread */
- ir->rx->t_notify = &tn;
- ir->rx->task = kthread_run(lirc_thread, ir, "lirc_zilog");
+ ir->rx->task = kthread_run(lirc_thread, ir,
+ "zilog-rx-i2c-%d", adap->nr);
if (IS_ERR(ir->rx->task)) {
ret = PTR_ERR(ir->rx->task);
zilog_error("%s: could not start IR Rx polling thread"
"\n", __func__);
goto out_free_xx;
}
- wait_for_completion(&tn);
- ir->rx->t_notify = NULL;
}
/* register with lirc */
@@ -1404,6 +1387,8 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
goto out_unregister;
}
+ zilog_info("probe of IR %s on %s (i2c-%d) done. IR unit ready.\n",
+ tx_probe ? "Tx" : "Rx", adap->name, adap->nr);
out_ok:
mutex_unlock(&ir_devices_lock);
return 0;

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