Merge branch 'x86/doc' into x86/core

[cascardo/linux.git] / drivers / media / dvb / dvb-core / dvb_ca_en50221.c

diff --git a/drivers/media/dvb/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb/dvb-core/dvb_ca_en50221.c
index 98ee167..7e3aeaa 100644 (file)
--- 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)) {