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Commit ded92846 authored by Andrew de Quincey's avatar Andrew de Quincey Committed by Linus Torvalds
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[PATCH] DVB: Fix locking problems and code cleanup 

Fix locking problems and code cleanup
Signed-off-by: default avatarAndrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: default avatarJohannes Stezenbach <js@linuxtv.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 69459f3d
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Showing with 23 additions and 46 deletions
drivers/media/dvb/dvb-core/dvb_ca_en50221.c
View file @ ded92846
......@@ -35,7 +35,7 @@
#include <linux/moduleparam.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/rwsem.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include "dvb_ca_en50221.h"
......@@ -111,9 +111,6 @@ struct dvb_ca_slot {
/* size of the buffer to use when talking to the CAM */
int link_buf_size;
/* semaphore for syncing access to slot structure */
struct rw_semaphore sem;
/* buffer for incoming packets */
struct dvb_ringbuffer rx_buffer;
......@@ -602,14 +599,11 @@ static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot, u8 * eb
if (ebuf == NULL) {
int buf_free;
down_read(&ca->slot_info[slot].sem);
if (ca->slot_info[slot].rx_buffer.data == NULL) {
up_read(&ca->slot_info[slot].sem);
status = -EIO;
goto exit;
}
buf_free = dvb_ringbuffer_free(&ca->slot_info[slot].rx_buffer);
up_read(&ca->slot_info[slot].sem);
if (buf_free < (ca->slot_info[slot].link_buf_size + DVB_RINGBUFFER_PKTHDRSIZE)) {
status = -EAGAIN;
......@@ -680,14 +674,11 @@ static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot, u8 * eb
/* OK, add it to the receive buffer, or copy into external buffer if supplied */
if (ebuf == NULL) {
down_read(&ca->slot_info[slot].sem);
if (ca->slot_info[slot].rx_buffer.data == NULL) {
up_read(&ca->slot_info[slot].sem);
status = -EIO;
goto exit;
}
dvb_ringbuffer_pkt_write(&ca->slot_info[slot].rx_buffer, buf, bytes_read);
up_read(&ca->slot_info[slot].sem);
} else {
memcpy(ebuf, buf, bytes_read);
}
......@@ -802,12 +793,8 @@ static int dvb_ca_en50221_slot_shutdown(struct dvb_ca_private *ca, int slot)
{
dprintk("%s\n", __FUNCTION__);
down_write(&ca->slot_info[slot].sem);
ca->pub->slot_shutdown(ca->pub, slot);
ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_NONE;
vfree(ca->slot_info[slot].rx_buffer.data);
ca->slot_info[slot].rx_buffer.data = NULL;
up_write(&ca->slot_info[slot].sem);
/* need to wake up all processes to check if they're now
trying to write to a defunct CAM */
......@@ -893,7 +880,7 @@ void dvb_ca_en50221_frda_irq(struct dvb_ca_en50221 *pubca, int slot)
case DVB_CA_SLOTSTATE_RUNNING:
if (ca->open)
dvb_ca_en50221_read_data(ca, slot, NULL, 0);
dvb_ca_en50221_thread_wakeup(ca);
break;
}
}
......@@ -1127,16 +1114,16 @@ static int dvb_ca_en50221_thread(void *data)
break;
}
rxbuf = vmalloc(RX_BUFFER_SIZE);
if (rxbuf == NULL) {
printk("dvb_ca adapter %d: Unable to allocate CAM rx buffer :(\n", ca->dvbdev->adapter->num);
ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
dvb_ca_en50221_thread_update_delay(ca);
break;
if (ca->slot_info[slot].rx_buffer.data == NULL) {
rxbuf = vmalloc(RX_BUFFER_SIZE);
if (rxbuf == NULL) {
printk("dvb_ca adapter %d: Unable to allocate CAM rx buffer :(\n", ca->dvbdev->adapter->num);
ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_INVALID;
dvb_ca_en50221_thread_update_delay(ca);
break;
}
dvb_ringbuffer_init(&ca->slot_info[slot].rx_buffer, rxbuf, RX_BUFFER_SIZE);
}
down_write(&ca->slot_info[slot].sem);
dvb_ringbuffer_init(&ca->slot_info[slot].rx_buffer, rxbuf, RX_BUFFER_SIZE);
up_write(&ca->slot_info[slot].sem);
ca->pub->slot_ts_enable(ca->pub, slot);
ca->slot_info[slot].slot_state = DVB_CA_SLOTSTATE_RUNNING;
......@@ -1148,11 +1135,7 @@ static int dvb_ca_en50221_thread(void *data)
if (!ca->open)
continue;
// no need to poll if the CAM supports IRQs
if (ca->slot_info[slot].da_irq_supported)
break;
// poll mode
// poll slots for data
pktcount = 0;
while ((status = dvb_ca_en50221_read_data(ca, slot, NULL, 0)) > 0) {
if (!ca->open)
......@@ -1367,12 +1350,13 @@ static ssize_t dvb_ca_en50221_io_write(struct file *file,
/**
* Condition for waking up in dvb_ca_en50221_io_read_condition
*/
static int dvb_ca_en50221_io_read_condition(struct dvb_ca_private *ca, int *result, int *_slot)
static int dvb_ca_en50221_io_read_condition(struct dvb_ca_private *ca,
int *result, int *_slot)
{
int slot;
int slot_count = 0;
int idx;
int fraglen;
size_t fraglen;
int connection_id = -1;
int found = 0;
u8 hdr[2];
......@@ -1382,10 +1366,7 @@ static int dvb_ca_en50221_io_read_condition(struct dvb_ca_private *ca, int *resu
if (ca->slot_info[slot].slot_state != DVB_CA_SLOTSTATE_RUNNING)
goto nextslot;
down_read(&ca->slot_info[slot].sem);
if (ca->slot_info[slot].rx_buffer.data == NULL) {
up_read(&ca->slot_info[slot].sem);
return 0;
}
......@@ -1403,10 +1384,7 @@ static int dvb_ca_en50221_io_read_condition(struct dvb_ca_private *ca, int *resu
idx = dvb_ringbuffer_pkt_next(&ca->slot_info[slot].rx_buffer, idx, &fraglen);
}
if (!found)
up_read(&ca->slot_info[slot].sem);
nextslot:
nextslot:
slot = (slot + 1) % ca->slot_count;
slot_count++;
}
......@@ -1511,8 +1489,7 @@ static ssize_t dvb_ca_en50221_io_read(struct file *file, char __user * buf,
goto exit;
status = pktlen;
exit:
up_read(&ca->slot_info[slot].sem);
exit:
return status;
}
......@@ -1544,11 +1521,11 @@ static int dvb_ca_en50221_io_open(struct inode *inode, struct file *file)
for (i = 0; i < ca->slot_count; i++) {
if (ca->slot_info[i].slot_state == DVB_CA_SLOTSTATE_RUNNING) {
down_write(&ca->slot_info[i].sem);
if (ca->slot_info[i].rx_buffer.data != NULL) {
/* it is safe to call this here without locks because
* ca->open == 0. Data is not read in this case */
dvb_ringbuffer_flush(&ca->slot_info[i].rx_buffer);
}
up_write(&ca->slot_info[i].sem);
}
}
......@@ -1607,7 +1584,6 @@ static unsigned int dvb_ca_en50221_io_poll(struct file *file, poll_table * wait)
dprintk("%s\n", __FUNCTION__);
if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1) {
up_read(&ca->slot_info[slot].sem);
mask |= POLLIN;
}
......@@ -1619,7 +1595,6 @@ static unsigned int dvb_ca_en50221_io_poll(struct file *file, poll_table * wait)
poll_wait(file, &ca->wait_queue, wait);
if (dvb_ca_en50221_io_read_condition(ca, &result, &slot) == 1) {
up_read(&ca->slot_info[slot].sem);
mask |= POLLIN;
}
......@@ -1709,7 +1684,6 @@ 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;
init_rwsem(&ca->slot_info[i].sem);
}
if (signal_pending(current)) {
......@@ -1729,7 +1703,7 @@ int dvb_ca_en50221_init(struct dvb_adapter *dvb_adapter,
ca->thread_pid = ret;
return 0;
error:
error:
if (ca != NULL) {
if (ca->dvbdev != NULL)
dvb_unregister_device(ca->dvbdev);
......@@ -1771,6 +1745,9 @@ void dvb_ca_en50221_release(struct dvb_ca_en50221 *pubca)
for (i = 0; i < ca->slot_count; i++) {
dvb_ca_en50221_slot_shutdown(ca, i);
if (ca->slot_info[i].rx_buffer.data != NULL) {
vfree(ca->slot_info[i].rx_buffer.data);
}
}
kfree(ca->slot_info);
dvb_unregister_device(ca->dvbdev);
......
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