DiBcom: protect the I2C bufer access
commit 79fcce3230b140f7675f8529ee53fe2f9644f902 upstream.
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>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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)