This patch adds a mutex to xc4000_priv, to protect the driver
from being accessed by multiple processes at the same time.
Signed-off-by: Istvan Varga <istvan_v@xxxxxxxxxx>
diff -uNr xc4000_orig/drivers/media/common/tuners/xc4000.c xc4000/drivers/media/common/tuners/xc4000.c
--- xc4000_orig/drivers/media/common/tuners/xc4000.c 2011-06-03 16:35:23.000000000 +0200
+++ xc4000/drivers/media/common/tuners/xc4000.c 2011-06-03 17:02:59.000000000 +0200
@@ -28,6 +28,7 @@
#include <linux/delay.h>
#include <linux/dvb/frontend.h>
#include <linux/i2c.h>
+#include <linux/mutex.h>
#include <asm/unaligned.h>
#include "dvb_frontend.h"
@@ -91,6 +92,7 @@
struct firmware_properties cur_fw;
__u16 hwmodel;
__u16 hwvers;
+ struct mutex lock;
};
/* Misc Defines */
@@ -1144,10 +1146,12 @@
{
struct xc4000_priv *priv = fe->tuner_priv;
unsigned int type;
- int ret;
+ int ret = -EREMOTEIO;
dprintk(1, "%s() frequency=%d (Hz)\n", __func__, params->frequency);
+ mutex_lock(&priv->lock);
+
if (fe->ops.info.type == FE_ATSC) {
dprintk(1, "%s() ATSC\n", __func__);
switch (params->u.vsb.modulation) {
@@ -1171,7 +1175,8 @@
type = DTV6;
break;
default:
- return -EINVAL;
+ ret = -EINVAL;
+ goto fail;
}
} else if (fe->ops.info.type == FE_OFDM) {
dprintk(1, "%s() OFDM\n", __func__);
@@ -1207,28 +1212,29 @@
break;
default:
printk(KERN_ERR "xc4000 bandwidth not set!\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto fail;
}
priv->rf_mode = XC_RF_MODE_AIR;
} else {
printk(KERN_ERR "xc4000 modulation type not supported!\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto fail;
}
dprintk(1, "%s() frequency=%d (compensated)\n",
__func__, priv->freq_hz);
/* Make sure the correct firmware type is loaded */
- if (check_firmware(fe, type, 0, priv->if_khz) != XC_RESULT_SUCCESS) {
- return -EREMOTEIO;
- }
+ if (check_firmware(fe, type, 0, priv->if_khz) != XC_RESULT_SUCCESS)
+ goto fail;
ret = xc_SetSignalSource(priv, priv->rf_mode);
if (ret != XC_RESULT_SUCCESS) {
printk(KERN_ERR
- "xc4000: xc_SetSignalSource(%d) failed\n",
- priv->rf_mode);
- return -EREMOTEIO;
+ "xc4000: xc_SetSignalSource(%d) failed\n",
+ priv->rf_mode);
+ goto fail;
}
ret = xc_SetTVStandard(priv,
@@ -1236,33 +1242,32 @@
XC4000_Standard[priv->video_standard].AudioMode);
if (ret != XC_RESULT_SUCCESS) {
printk(KERN_ERR "xc4000: xc_SetTVStandard failed\n");
- return -EREMOTEIO;
- }
-#ifdef DJH_DEBUG
- ret = xc_set_IF_frequency(priv, priv->if_khz);
- if (ret != XC_RESULT_SUCCESS) {
- printk(KERN_ERR "xc4000: xc_Set_IF_frequency(%d) failed\n",
- priv->if_khz);
- return -EIO;
+ goto fail;
}
-#endif
xc_tune_channel(priv, priv->freq_hz, XC_TUNE_DIGITAL);
if (debug)
xc_debug_dump(priv);
- return 0;
+ ret = 0;
+
+fail:
+ mutex_unlock(&priv->lock);
+
+ return ret;
}
static int xc4000_set_analog_params(struct dvb_frontend *fe,
struct analog_parameters *params)
{
struct xc4000_priv *priv = fe->tuner_priv;
- int ret;
+ int ret = -EREMOTEIO;
dprintk(1, "%s() frequency=%d (in units of 62.5khz)\n",
__func__, params->frequency);
+ mutex_lock(&priv->lock);
+
/* Fix me: it could be air. */
priv->rf_mode = params->mode;
if (params->mode > XC_RF_MODE_CABLE)
@@ -1317,16 +1322,15 @@
tune_channel:
/* FIXME - firmware type not being set properly */
- if (check_firmware(fe, DTV8, 0, priv->if_khz) != XC_RESULT_SUCCESS) {
- return -EREMOTEIO;
- }
+ if (check_firmware(fe, DTV8, 0, priv->if_khz) != XC_RESULT_SUCCESS)
+ goto fail;
ret = xc_SetSignalSource(priv, priv->rf_mode);
if (ret != XC_RESULT_SUCCESS) {
printk(KERN_ERR
- "xc4000: xc_SetSignalSource(%d) failed\n",
- priv->rf_mode);
- return -EREMOTEIO;
+ "xc4000: xc_SetSignalSource(%d) failed\n",
+ priv->rf_mode);
+ goto fail;
}
ret = xc_SetTVStandard(priv,
@@ -1334,7 +1338,7 @@
XC4000_Standard[priv->video_standard].AudioMode);
if (ret != XC_RESULT_SUCCESS) {
printk(KERN_ERR "xc4000: xc_SetTVStandard failed\n");
- return -EREMOTEIO;
+ goto fail;
}
xc_tune_channel(priv, priv->freq_hz, XC_TUNE_ANALOG);
@@ -1342,7 +1346,12 @@
if (debug)
xc_debug_dump(priv);
- return 0;
+ ret = 0;
+
+fail:
+ mutex_unlock(&priv->lock);
+
+ return ret;
}
static int xc4000_get_frequency(struct dvb_frontend *fe, u32 *freq)
@@ -1367,8 +1376,12 @@
struct xc4000_priv *priv = fe->tuner_priv;
u16 lock_status = 0;
+ mutex_lock(&priv->lock);
+
xc_get_lock_status(priv, &lock_status);
+ mutex_unlock(&priv->lock);
+
dprintk(1, "%s() lock_status = 0x%08x\n", __func__, lock_status);
*status = lock_status;
@@ -1385,9 +1398,13 @@
static int xc4000_init(struct dvb_frontend *fe)
{
struct xc4000_priv *priv = fe->tuner_priv;
+ int ret;
dprintk(1, "%s()\n", __func__);
- if (check_firmware(fe, DTV8, 0, priv->if_khz) != XC_RESULT_SUCCESS) {
+ mutex_lock(&priv->lock);
+ ret = check_firmware(fe, DTV8, 0, priv->if_khz);
+ mutex_unlock(&priv->lock);
+ if (ret != XC_RESULT_SUCCESS) {
printk(KERN_ERR "xc4000: Unable to initialise tuner\n");
return -EREMOTEIO;
}
@@ -1471,6 +1488,7 @@
case 1:
/* new tuner instance */
priv->bandwidth = BANDWIDTH_6_MHZ;
+ mutex_init(&priv->lock);
fe->tuner_priv = priv;
break;
default:
@@ -1522,7 +1540,9 @@
/* FIXME: For now, load the firmware at startup. We will remove this
before the code goes to production... */
+ mutex_lock(&priv->lock);
check_firmware(fe, DTV8, 0, priv->if_khz);
+ mutex_unlock(&priv->lock);
return fe;
fail:
