diff options
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/dvb/dvb-core/dvb_ca_en50221.c | 24 | ||||
| -rw-r--r-- | drivers/media/dvb/dvb-core/dvb_ca_en50221.h | 6 |
2 files changed, 25 insertions, 5 deletions
diff --git a/drivers/media/dvb/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb/dvb-core/dvb_ca_en50221.c index 98ee16773ff..7e3aeaa7370 100644 --- a/drivers/media/dvb/dvb-core/dvb_ca_en50221.c +++ b/drivers/media/dvb/dvb-core/dvb_ca_en50221.c @@ -93,6 +93,9 @@ struct dvb_ca_slot { /* current state of the CAM */ int slot_state; + /* mutex used for serializing access to one CI slot */ + struct mutex slot_lock; + /* Number of CAMCHANGES that have occurred since last processing */ atomic_t camchange_count; @@ -711,14 +714,20 @@ static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot, u8 * b dprintk("%s\n", __func__); - // sanity check + /* sanity check */ if (bytes_write > ca->slot_info[slot].link_buf_size) return -EINVAL; - /* check if interface is actually waiting for us to read from it, or if a read is in progress */ + /* it is possible we are dealing with a single buffer implementation, + thus if there is data available for read or if there is even a read + already in progress, we do nothing but awake the kernel thread to + process the data if necessary. */ if ((status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS)) < 0) goto exitnowrite; if (status & (STATUSREG_DA | STATUSREG_RE)) { + if (status & STATUSREG_DA) + dvb_ca_en50221_thread_wakeup(ca); + status = -EAGAIN; goto exitnowrite; } @@ -987,6 +996,8 @@ static int dvb_ca_en50221_thread(void *data) /* go through all the slots processing them */ for (slot = 0; slot < ca->slot_count; slot++) { + mutex_lock(&ca->slot_info[slot].slot_lock); + // check the cam status + deal with CAMCHANGEs while (dvb_ca_en50221_check_camstatus(ca, slot)) { /* clear down an old CI slot if necessary */ @@ -1122,7 +1133,7 @@ static int dvb_ca_en50221_thread(void *data) case DVB_CA_SLOTSTATE_RUNNING: if (!ca->open) - continue; + break; // poll slots for data pktcount = 0; @@ -1146,6 +1157,8 @@ static int dvb_ca_en50221_thread(void *data) } break; } + + mutex_unlock(&ca->slot_info[slot].slot_lock); } } @@ -1181,6 +1194,7 @@ static int dvb_ca_en50221_io_do_ioctl(struct inode *inode, struct file *file, switch (cmd) { case CA_RESET: for (slot = 0; slot < ca->slot_count; slot++) { + mutex_lock(&ca->slot_info[slot].slot_lock); if (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_NONE) { dvb_ca_en50221_slot_shutdown(ca, slot); if (ca->flags & DVB_CA_EN50221_FLAG_IRQ_CAMCHANGE) @@ -1188,6 +1202,7 @@ static int dvb_ca_en50221_io_do_ioctl(struct inode *inode, struct file *file, slot, DVB_CA_EN50221_CAMCHANGE_INSERTED); } + mutex_unlock(&ca->slot_info[slot].slot_lock); } ca->next_read_slot = 0; dvb_ca_en50221_thread_wakeup(ca); @@ -1308,7 +1323,9 @@ static ssize_t dvb_ca_en50221_io_write(struct file *file, goto exit; } + mutex_lock(&ca->slot_info[slot].slot_lock); status = dvb_ca_en50221_write_data(ca, slot, fragbuf, fraglen + 2); + mutex_unlock(&ca->slot_info[slot].slot_lock); if (status == (fraglen + 2)) { written = 1; break; @@ -1664,6 +1681,7 @@ int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter, ca->slot_info[i].slot_state = DVB_CA_SLOTSTATE_NONE; atomic_set(&ca->slot_info[i].camchange_count, 0); ca->slot_info[i].camchange_type = DVB_CA_EN50221_CAMCHANGE_REMOVED; + mutex_init(&ca->slot_info[i].slot_lock); } if (signal_pending(current)) { diff --git a/drivers/media/dvb/dvb-core/dvb_ca_en50221.h b/drivers/media/dvb/dvb-core/dvb_ca_en50221.h index 8467e63ddc0..7df2e141187 100644 --- a/drivers/media/dvb/dvb-core/dvb_ca_en50221.h +++ b/drivers/media/dvb/dvb-core/dvb_ca_en50221.h @@ -45,8 +45,10 @@ struct dvb_ca_en50221 { /* the module owning this structure */ struct module* owner; - /* NOTE: the read_*, write_* and poll_slot_status functions must use locks as - * they may be called from several threads at once */ + /* NOTE: the read_*, write_* and poll_slot_status functions will be + * called for different slots concurrently and need to use locks where + * and if appropriate. There will be no concurrent access to one slot. + */ /* functions for accessing attribute memory on the CAM */ int (*read_attribute_mem)(struct dvb_ca_en50221* ca, int slot, int address); |