[media] DiBcom: protect the I2C bufer access
This patch protects the I2C buffer access in order to manage concurrent
access. This protection is done using mutex.
Furthermore, for the dib9000, if a pid filtering command is
received during the tuning, this pid filtering command is delayed to
avoid any concurrent access issue.
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Florian Mickler <florian@mickler.org>
Cc: stable@kernel.org
Signed-off-by: Olivier Grenie <olivier.grenie@dibcom.fr>
Signed-off-by: Patrick Boettcher <Patrick.Boettcher@dibcom.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb/frontends/dib0090.c b/drivers/media/dvb/frontends/dib0090.c
index c9c935a..b174d1c 100644
--- a/drivers/media/dvb/frontends/dib0090.c
+++ b/drivers/media/dvb/frontends/dib0090.c
@@ -27,6 +27,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/i2c.h>
+#include <linux/mutex.h>
#include "dvb_frontend.h"
@@ -196,6 +197,7 @@
struct i2c_msg msg[2];
u8 i2c_write_buffer[3];
u8 i2c_read_buffer[2];
+ struct mutex i2c_buffer_lock;
};
struct dib0090_fw_state {
@@ -208,10 +210,18 @@
struct i2c_msg msg;
u8 i2c_write_buffer[2];
u8 i2c_read_buffer[2];
+ struct mutex i2c_buffer_lock;
};
static u16 dib0090_read_reg(struct dib0090_state *state, u8 reg)
{
+ u16 ret;
+
+ if (mutex_lock_interruptible(&state->i2c_buffer_lock) < 0) {
+ dprintk("could not acquire lock");
+ return 0;
+ }
+
state->i2c_write_buffer[0] = reg;
memset(state->msg, 0, 2 * sizeof(struct i2c_msg));
@@ -226,14 +236,24 @@
if (i2c_transfer(state->i2c, state->msg, 2) != 2) {
printk(KERN_WARNING "DiB0090 I2C read failed\n");
- return 0;
- }
+ ret = 0;
+ } else
+ ret = (state->i2c_read_buffer[0] << 8)
+ | state->i2c_read_buffer[1];
- return (state->i2c_read_buffer[0] << 8) | state->i2c_read_buffer[1];
+ mutex_unlock(&state->i2c_buffer_lock);
+ return ret;
}
static int dib0090_write_reg(struct dib0090_state *state, u32 reg, u16 val)
{
+ int ret;
+
+ if (mutex_lock_interruptible(&state->i2c_buffer_lock) < 0) {
+ dprintk("could not acquire lock");
+ return -EINVAL;
+ }
+
state->i2c_write_buffer[0] = reg & 0xff;
state->i2c_write_buffer[1] = val >> 8;
state->i2c_write_buffer[2] = val & 0xff;
@@ -246,13 +266,23 @@
if (i2c_transfer(state->i2c, state->msg, 1) != 1) {
printk(KERN_WARNING "DiB0090 I2C write failed\n");
- return -EREMOTEIO;
- }
- return 0;
+ ret = -EREMOTEIO;
+ } else
+ ret = 0;
+
+ mutex_unlock(&state->i2c_buffer_lock);
+ return ret;
}
static u16 dib0090_fw_read_reg(struct dib0090_fw_state *state, u8 reg)
{
+ u16 ret;
+
+ if (mutex_lock_interruptible(&state->i2c_buffer_lock) < 0) {
+ dprintk("could not acquire lock");
+ return 0;
+ }
+
state->i2c_write_buffer[0] = reg;
memset(&state->msg, 0, sizeof(struct i2c_msg));
@@ -262,13 +292,24 @@
state->msg.len = 2;
if (i2c_transfer(state->i2c, &state->msg, 1) != 1) {
printk(KERN_WARNING "DiB0090 I2C read failed\n");
- return 0;
- }
- return (state->i2c_read_buffer[0] << 8) | state->i2c_read_buffer[1];
+ ret = 0;
+ } else
+ ret = (state->i2c_read_buffer[0] << 8)
+ | state->i2c_read_buffer[1];
+
+ mutex_unlock(&state->i2c_buffer_lock);
+ return ret;
}
static int dib0090_fw_write_reg(struct dib0090_fw_state *state, u8 reg, u16 val)
{
+ int ret;
+
+ if (mutex_lock_interruptible(&state->i2c_buffer_lock) < 0) {
+ dprintk("could not acquire lock");
+ return -EINVAL;
+ }
+
state->i2c_write_buffer[0] = val >> 8;
state->i2c_write_buffer[1] = val & 0xff;
@@ -279,9 +320,12 @@
state->msg.len = 2;
if (i2c_transfer(state->i2c, &state->msg, 1) != 1) {
printk(KERN_WARNING "DiB0090 I2C write failed\n");
- return -EREMOTEIO;
- }
- return 0;
+ ret = -EREMOTEIO;
+ } else
+ ret = 0;
+
+ mutex_unlock(&state->i2c_buffer_lock);
+ return ret;
}
#define HARD_RESET(state) do { if (cfg->reset) { if (cfg->sleep) cfg->sleep(fe, 0); msleep(10); cfg->reset(fe, 1); msleep(10); cfg->reset(fe, 0); msleep(10); } } while (0)
@@ -2440,6 +2484,7 @@
st->config = config;
st->i2c = i2c;
st->fe = fe;
+ mutex_init(&st->i2c_buffer_lock);
fe->tuner_priv = st;
if (config->wbd == NULL)
@@ -2471,6 +2516,7 @@
st->config = config;
st->i2c = i2c;
st->fe = fe;
+ mutex_init(&st->i2c_buffer_lock);
fe->tuner_priv = st;
if (dib0090_fw_reset_digital(fe, st->config) != 0)