From 3165ca2068855d7118d78396adce4c49a4e7f636 Mon Sep 17 00:00:00 2001 From: Devin Heitmueller Date: Mon, 4 May 2009 20:43:02 -0400 Subject: dvb_frontend: fix race condition resulting in dropped tuning commands From: Devin Heitmueller A race condition was detected in the case that putting the tuner to sleep takes an unusually long period of time, combined with applications that quickly close/open the dvb frontend. The kaffeine channel scanner closes and reopens the dvb frontend between each tuning attempt. If it takes an unusually longer period of time to put the tuner to sleep (for example, the Pinnacle 801e takes 660 ms), the dvb_frontend thread will still be in a running state (and hence fepriv->thread is still set) but the fepriv->exit field will still be zero. As a result, if a dvb_frontend_start() call arrives while the frontend thread is in the process of terminating, the call will return 0 without actually starting a new thread. This results in the tuning request being dropped. To address this, mark fepriv->exit as soon as we know the thread is going to be terminated, so that dvb_frontend_start() knows to start a new instance. Problem encountered with Kaffeine 0.8.7 doing ATSC scanning against the Pinnacle 801e tuner, in conjunction with new code to power down the xc5000 when not in use. Priority: normal Signed-off-by: Devin Heitmueller --- linux/drivers/media/dvb/dvb-core/dvb_frontend.c | 1 + 1 file changed, 1 insertion(+) (limited to 'linux/drivers/media/dvb') diff --git a/linux/drivers/media/dvb/dvb-core/dvb_frontend.c b/linux/drivers/media/dvb/dvb-core/dvb_frontend.c index da2890b22..d359f6841 100644 --- a/linux/drivers/media/dvb/dvb-core/dvb_frontend.c +++ b/linux/drivers/media/dvb/dvb-core/dvb_frontend.c @@ -554,6 +554,7 @@ restart: if (kthread_should_stop() || dvb_frontend_is_exiting(fe)) { /* got signal or quitting */ + fepriv->exit = 1; break; } -- cgit v1.2.3 From 8daa6a71db80a0910916ffe840d4c9dc520e1310 Mon Sep 17 00:00:00 2001 From: Devin Heitmueller Date: Mon, 4 May 2009 20:57:41 -0400 Subject: dib0700: reduce xc5000 sleep time for Pinnacle 801e to 10ms From: Devin Heitmueller According to the xc5000 spec, the reset pin only needs to be held low for 10ms. Priority: normal Signed-off-by: Devin Heitmueller --- linux/drivers/media/dvb/dvb-usb/dib0700_devices.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'linux/drivers/media/dvb') diff --git a/linux/drivers/media/dvb/dvb-usb/dib0700_devices.c b/linux/drivers/media/dvb/dvb-usb/dib0700_devices.c index e39993df0..ac97b9f42 100644 --- a/linux/drivers/media/dvb/dvb-usb/dib0700_devices.c +++ b/linux/drivers/media/dvb/dvb-usb/dib0700_devices.c @@ -1346,9 +1346,9 @@ static int dib0700_xc5000_tuner_callback(void *priv, int component, if (command == XC5000_TUNER_RESET) { /* Reset the tuner */ dib0700_set_gpio(adap->dev, GPIO1, GPIO_OUT, 0); - msleep(330); /* from Windows USB trace */ + msleep(10); dib0700_set_gpio(adap->dev, GPIO1, GPIO_OUT, 1); - msleep(330); /* from Windows USB trace */ + msleep(10); } else { err("xc5000: unknown tuner callback command: %d\n", command); return -EINVAL; -- cgit v1.2.3