[PATCH] dvb: dst: protect the read/write commands with a mutex
We need to protect the read/write commands with a mutex.
Bug reported by Henrik Sjoberg <henke@epact.se>
Signed-off-by: Manu Abraham <manu@linuxtv.org>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Cc: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/media/dvb/bt8xx/dst.c b/drivers/media/dvb/bt8xx/dst.c
index bc833a5..0c718dc 100644
--- a/drivers/media/dvb/bt8xx/dst.c
+++ b/drivers/media/dvb/bt8xx/dst.c
@@ -910,6 +910,7 @@
static int dst_probe(struct dst_state *state)
{
+ sema_init(&state->dst_mutex, 1);
if ((rdc_8820_reset(state)) < 0) {
dprintk(verbose, DST_ERROR, 1, "RDC 8820 RESET Failed.");
return -1;
@@ -960,21 +961,23 @@
int dst_command(struct dst_state *state, u8 *data, u8 len)
{
u8 reply;
+
+ down(&state->dst_mutex);
if ((dst_comm_init(state)) < 0) {
dprintk(verbose, DST_NOTICE, 1, "DST Communication Initialization Failed.");
- return -1;
+ goto error;
}
if (write_dst(state, data, len)) {
dprintk(verbose, DST_INFO, 1, "Tring to recover.. ");
if ((dst_error_recovery(state)) < 0) {
dprintk(verbose, DST_ERROR, 1, "Recovery Failed.");
- return -1;
+ goto error;
}
- return -1;
+ goto error;
}
if ((dst_pio_disable(state)) < 0) {
dprintk(verbose, DST_ERROR, 1, "PIO Disable Failed.");
- return -1;
+ goto error;
}
if (state->type_flags & DST_TYPE_HAS_FW_1)
udelay(3000);
@@ -982,36 +985,41 @@
dprintk(verbose, DST_DEBUG, 1, "Trying to recover.. ");
if ((dst_error_recovery(state)) < 0) {
dprintk(verbose, DST_INFO, 1, "Recovery Failed.");
- return -1;
+ goto error;
}
- return -1;
+ goto error;
}
if (reply != ACK) {
dprintk(verbose, DST_INFO, 1, "write not acknowledged 0x%02x ", reply);
- return -1;
+ goto error;
}
if (len >= 2 && data[0] == 0 && (data[1] == 1 || data[1] == 3))
- return 0;
+ goto error;
if (state->type_flags & DST_TYPE_HAS_FW_1)
udelay(3000);
else
udelay(2000);
if (!dst_wait_dst_ready(state, NO_DELAY))
- return -1;
+ goto error;
if (read_dst(state, state->rxbuffer, FIXED_COMM)) {
dprintk(verbose, DST_DEBUG, 1, "Trying to recover.. ");
if ((dst_error_recovery(state)) < 0) {
dprintk(verbose, DST_INFO, 1, "Recovery failed.");
- return -1;
+ goto error;
}
- return -1;
+ goto error;
}
if (state->rxbuffer[7] != dst_check_sum(state->rxbuffer, 7)) {
dprintk(verbose, DST_INFO, 1, "checksum failure");
- return -1;
+ goto error;
}
-
+ up(&state->dst_mutex);
return 0;
+
+error:
+ up(&state->dst_mutex);
+ return -EIO;
+
}
EXPORT_SYMBOL(dst_command);