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[media] media: dvb-core move fe exit flag from fepriv to fe for drive…
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…r access

Some fe drivers attempt to access the device for power control from
their release routines. When release routines are called after device
is disconnected, the attempts fail. fe drivers should avoid accessing
the device, from their release interfaces when called from disconnect
path. dvb-frontend maintains exit flag to keep track when fe device is
disconnected in its private data structures. Export the flag in fe to
enable drivers to check the device status from their release interfaces.

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
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Shuah Khan authored and Mauro Carvalho Chehab committed Jul 26, 2014
1 parent cc5c5d2 commit 18ed286
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Showing 2 changed files with 16 additions and 15 deletions.
26 changes: 11 additions & 15 deletions drivers/media/dvb-core/dvb_frontend.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -96,10 +96,6 @@ MODULE_PARM_DESC(dvb_mfe_wait_time, "Wait up to <mfe_wait_time> seconds on open(
* FESTATE_LOSTLOCK. When the lock has been lost, and we're searching it again.
*/

#define DVB_FE_NO_EXIT 0
#define DVB_FE_NORMAL_EXIT 1
#define DVB_FE_DEVICE_REMOVED 2

static DEFINE_MUTEX(frontend_mutex);

struct dvb_frontend_private {
Expand All @@ -113,7 +109,6 @@ struct dvb_frontend_private {
wait_queue_head_t wait_queue;
struct task_struct *thread;
unsigned long release_jiffies;
unsigned int exit;
unsigned int wakeup;
fe_status_t status;
unsigned long tune_mode_flags;
Expand Down Expand Up @@ -565,7 +560,7 @@ static int dvb_frontend_is_exiting(struct dvb_frontend *fe)
{
struct dvb_frontend_private *fepriv = fe->frontend_priv;

if (fepriv->exit != DVB_FE_NO_EXIT)
if (fe->exit != DVB_FE_NO_EXIT)
return 1;

if (fepriv->dvbdev->writers == 1)
Expand Down Expand Up @@ -629,7 +624,7 @@ static int dvb_frontend_thread(void *data)
/* got signal or quitting */
if (!down_interruptible(&fepriv->sem))
semheld = true;
fepriv->exit = DVB_FE_NORMAL_EXIT;
fe->exit = DVB_FE_NORMAL_EXIT;
break;
}

Expand Down Expand Up @@ -739,9 +734,9 @@ static int dvb_frontend_thread(void *data)

fepriv->thread = NULL;
if (kthread_should_stop())
fepriv->exit = DVB_FE_DEVICE_REMOVED;
fe->exit = DVB_FE_DEVICE_REMOVED;
else
fepriv->exit = DVB_FE_NO_EXIT;
fe->exit = DVB_FE_NO_EXIT;
mb();

if (semheld)
Expand All @@ -756,7 +751,8 @@ static void dvb_frontend_stop(struct dvb_frontend *fe)

dev_dbg(fe->dvb->device, "%s:\n", __func__);

fepriv->exit = DVB_FE_NORMAL_EXIT;
if (fe->exit != DVB_FE_DEVICE_REMOVED)
fe->exit = DVB_FE_NORMAL_EXIT;
mb();

if (!fepriv->thread)
Expand Down Expand Up @@ -826,7 +822,7 @@ static int dvb_frontend_start(struct dvb_frontend *fe)
dev_dbg(fe->dvb->device, "%s:\n", __func__);

if (fepriv->thread) {
if (fepriv->exit == DVB_FE_NO_EXIT)
if (fe->exit == DVB_FE_NO_EXIT)
return 0;
else
dvb_frontend_stop (fe);
Expand All @@ -838,7 +834,7 @@ static int dvb_frontend_start(struct dvb_frontend *fe)
return -EINTR;

fepriv->state = FESTATE_IDLE;
fepriv->exit = DVB_FE_NO_EXIT;
fe->exit = DVB_FE_NO_EXIT;
fepriv->thread = NULL;
mb();

Expand Down Expand Up @@ -1906,7 +1902,7 @@ static int dvb_frontend_ioctl(struct file *file,
if (down_interruptible(&fepriv->sem))
return -ERESTARTSYS;

if (fepriv->exit != DVB_FE_NO_EXIT) {
if (fe->exit != DVB_FE_NO_EXIT) {
up(&fepriv->sem);
return -ENODEV;
}
Expand Down Expand Up @@ -2424,7 +2420,7 @@ static int dvb_frontend_open(struct inode *inode, struct file *file)
int ret;

dev_dbg(fe->dvb->device, "%s:\n", __func__);
if (fepriv->exit == DVB_FE_DEVICE_REMOVED)
if (fe->exit == DVB_FE_DEVICE_REMOVED)
return -ENODEV;

if (adapter->mfe_shared) {
Expand Down Expand Up @@ -2529,7 +2525,7 @@ static int dvb_frontend_release(struct inode *inode, struct file *file)

if (dvbdev->users == -1) {
wake_up(&fepriv->wait_queue);
if (fepriv->exit != DVB_FE_NO_EXIT)
if (fe->exit != DVB_FE_NO_EXIT)
wake_up(&dvbdev->wait_queue);
if (fe->ops.ts_bus_ctrl)
fe->ops.ts_bus_ctrl(fe, 0);
Expand Down
5 changes: 5 additions & 0 deletions drivers/media/dvb-core/dvb_frontend.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -405,6 +405,10 @@ struct dtv_frontend_properties {
struct dtv_fe_stats block_count;
};

#define DVB_FE_NO_EXIT 0
#define DVB_FE_NORMAL_EXIT 1
#define DVB_FE_DEVICE_REMOVED 2

struct dvb_frontend {
struct dvb_frontend_ops ops;
struct dvb_adapter *dvb;
Expand All @@ -418,6 +422,7 @@ struct dvb_frontend {
#define DVB_FRONTEND_COMPONENT_DEMOD 1
int (*callback)(void *adapter_priv, int component, int cmd, int arg);
int id;
unsigned int exit;
};

extern int dvb_register_frontend(struct dvb_adapter *dvb,
Expand Down

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