From: Andy Walls Date: Sun, 16 Jan 2011 01:02:05 +0000 (-0300) Subject: [media] lirc_zilog: Update IR Rx polling kthread start/stop and some printks X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=b757730b022b4b1367d0435fcaa1b0a01e8aef42;p=deliverable%2Flinux.git [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 Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/staging/lirc/lirc_zilog.c b/drivers/staging/lirc/lirc_zilog.c index f2e8c63fa5bd..f7aa5e4e98b3 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;