[REVIEW,1/5] dvb_usb_v2: replace Kernel userspace lock with wait queue

Message ID	1362879755-4839-1-git-send-email-crope@iki.fi (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-media-owner@vger.kernel.org> From: Antti Palosaari <crope@iki.fi> To: linux-media@vger.kernel.org Cc: Antti Palosaari <crope@iki.fi> Subject: [REVIEW PATCH 1/5] dvb_usb_v2: replace Kernel userspace lock with wait queue Date: Sun, 10 Mar 2013 03:42:31 +0200 Message-Id: <1362879755-4839-1-git-send-email-crope@iki.fi> Sender: linux-media-owner@vger.kernel.org Precedence: bulk

================================================ [ BUG: lock held when returning to user space! ] 3.9.0-rc1+ #38 Tainted: G O ------------------------------------------------ tzap/4614 is leaving the kernel with locks still held! 1 lock held by tzap/4614: Signed-off-by: Antti Palosaari <crope@iki.fi> --- drivers/media/usb/dvb-usb-v2/dvb_usb.h | 5 ++- drivers/media/usb/dvb-usb-v2/dvb_usb_core.c | 53 ++++++++++++++++++++--------- 2 files changed, 41 insertions(+), 17 deletions(-) diff --git a/drivers/media/usb/dvb-usb-v2/dvb_usb.h b/drivers/media/usb/dvb-usb-v2/dvb_usb.h index 3cac8bd..ac1f145 100644 --- a/drivers/media/usb/dvb-usb-v2/dvb_usb.h +++ b/drivers/media/usb/dvb-usb-v2/dvb_usb.h @@ -329,13 +329,16 @@ struct dvb_usb_adapter { u8 feed_count; u8 max_feed_count; s8 active_fe; +#define ADAP_INIT 0 +#define ADAP_SLEEP 1 +#define ADAP_STREAMING 2 + unsigned long state_bits; /* dvb */ struct dvb_adapter dvb_adap; struct dmxdev dmxdev; struct dvb_demux demux; struct dvb_net dvb_net; - struct mutex sync_mutex; struct dvb_frontend *fe[MAX_NO_OF_FE_PER_ADAP]; int (*fe_init[MAX_NO_OF_FE_PER_ADAP]) (struct dvb_frontend *); diff --git a/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c b/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c index 0867920..c91da3c 100644 --- a/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c +++ b/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c @@ -253,6 +253,13 @@ static int dvb_usbv2_adapter_stream_exit(struct dvb_usb_adapter *adap) return usb_urb_exitv2(&adap->stream); } +static int wait_schedule(void *ptr) +{ + schedule(); + + return 0; +} + static inline int dvb_usb_ctrl_feed(struct dvb_demux_feed *dvbdmxfeed, int count) { @@ -266,6 +273,9 @@ static inline int dvb_usb_ctrl_feed(struct dvb_demux_feed *dvbdmxfeed, dvbdmxfeed->pid, dvbdmxfeed->index, (count == 1) ? "on" : "off"); + wait_on_bit(&adap->state_bits, ADAP_INIT, wait_schedule, + TASK_UNINTERRUPTIBLE); + if (adap->active_fe == -1) return -EINVAL; @@ -283,11 +293,14 @@ static inline int dvb_usb_ctrl_feed(struct dvb_demux_feed *dvbdmxfeed, "failed=%d\n", KBUILD_MODNAME, ret); usb_urb_killv2(&adap->stream); - goto err_mutex_unlock; + goto err_clear_wait; } } usb_urb_killv2(&adap->stream); - mutex_unlock(&adap->sync_mutex); + + clear_bit(ADAP_STREAMING, &adap->state_bits); + smp_mb__after_clear_bit(); + wake_up_bit(&adap->state_bits, ADAP_STREAMING); } /* activate the pid on the device pid filter */ @@ -303,7 +316,7 @@ static inline int dvb_usb_ctrl_feed(struct dvb_demux_feed *dvbdmxfeed, /* start feeding if it is first pid */ if (adap->feed_count == 1 && count == 1) { struct usb_data_stream_properties stream_props; - mutex_lock(&adap->sync_mutex); + set_bit(ADAP_STREAMING, &adap->state_bits); dev_dbg(&d->udev->dev, "%s: start feeding\n", __func__); /* resolve input and output streaming paramters */ @@ -314,7 +327,7 @@ static inline int dvb_usb_ctrl_feed(struct dvb_demux_feed *dvbdmxfeed, adap->fe[adap->active_fe], &adap->ts_type, &stream_props); if (ret < 0) - goto err_mutex_unlock; + goto err_clear_wait; } else { stream_props = adap->props->stream; } @@ -344,7 +357,7 @@ static inline int dvb_usb_ctrl_feed(struct dvb_demux_feed *dvbdmxfeed, dev_err(&d->udev->dev, "%s: " \ "pid_filter_ctrl() failed=%d\n", KBUILD_MODNAME, ret); - goto err_mutex_unlock; + goto err_clear_wait; } } @@ -355,14 +368,16 @@ static inline int dvb_usb_ctrl_feed(struct dvb_demux_feed *dvbdmxfeed, dev_err(&d->udev->dev, "%s: streaming_ctrl() " \ "failed=%d\n", KBUILD_MODNAME, ret); - goto err_mutex_unlock; + goto err_clear_wait; } } } return 0; -err_mutex_unlock: - mutex_unlock(&adap->sync_mutex); +err_clear_wait: + clear_bit(ADAP_STREAMING, &adap->state_bits); + smp_mb__after_clear_bit(); + wake_up_bit(&adap->state_bits, ADAP_STREAMING); dev_dbg(&d->udev->dev, "%s: failed=%d\n", __func__, ret); return ret; } @@ -435,8 +450,6 @@ static int dvb_usbv2_adapter_dvb_init(struct dvb_usb_adapter *adap) goto err_dvb_net_init; } - mutex_init(&adap->sync_mutex); - return 0; err_dvb_net_init: dvb_dmxdev_release(&adap->dmxdev); @@ -500,7 +513,7 @@ static int dvb_usb_fe_init(struct dvb_frontend *fe) if (!adap->suspend_resume_active) { adap->active_fe = fe->id; - mutex_lock(&adap->sync_mutex); + set_bit(ADAP_INIT, &adap->state_bits); } ret = dvb_usbv2_device_power_ctrl(d, 1); @@ -519,8 +532,11 @@ static int dvb_usb_fe_init(struct dvb_frontend *fe) goto err; } err: - if (!adap->suspend_resume_active) - mutex_unlock(&adap->sync_mutex); + if (!adap->suspend_resume_active) { + clear_bit(ADAP_INIT, &adap->state_bits); + smp_mb__after_clear_bit(); + wake_up_bit(&adap->state_bits, ADAP_INIT); + } dev_dbg(&d->udev->dev, "%s: ret=%d\n", __func__, ret); return ret; @@ -534,8 +550,11 @@ static int dvb_usb_fe_sleep(struct dvb_frontend *fe) dev_dbg(&d->udev->dev, "%s: adap=%d fe=%d\n", __func__, adap->id, fe->id); - if (!adap->suspend_resume_active) - mutex_lock(&adap->sync_mutex); + if (!adap->suspend_resume_active) { + set_bit(ADAP_SLEEP, &adap->state_bits); + wait_on_bit(&adap->state_bits, ADAP_STREAMING, wait_schedule, + TASK_UNINTERRUPTIBLE); + } if (adap->fe_sleep[fe->id]) { ret = adap->fe_sleep[fe->id](fe); @@ -555,7 +574,9 @@ static int dvb_usb_fe_sleep(struct dvb_frontend *fe) err: if (!adap->suspend_resume_active) { adap->active_fe = -1; - mutex_unlock(&adap->sync_mutex); + clear_bit(ADAP_SLEEP, &adap->state_bits); + smp_mb__after_clear_bit(); + wake_up_bit(&adap->state_bits, ADAP_SLEEP); } dev_dbg(&d->udev->dev, "%s: ret=%d\n", __func__, ret);

[REVIEW,1/5] dvb_usb_v2: replace Kernel userspace lock with wait queue

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Patch