diff options
author | Patrick Boettcher <Patrick.Boettcher@dibcom.fr> | 2011-08-03 15:08:21 (GMT) |
---|---|---|
committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-08-06 12:25:15 (GMT) |
commit | 79fcce3230b140f7675f8529ee53fe2f9644f902 (patch) | |
tree | 548f87873e553e0c0e69e13f78c360e0d351f857 /drivers/media/dvb/frontends/dib8000.c | |
parent | a5f2db539bd2a977cdee3fecc5c15dd0941c1ab3 (diff) | |
download | linux-79fcce3230b140f7675f8529ee53fe2f9644f902.tar.xz |
[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>
Diffstat (limited to 'drivers/media/dvb/frontends/dib8000.c')
-rw-r--r-- | drivers/media/dvb/frontends/dib8000.c | 72 |
1 files changed, 61 insertions, 11 deletions
diff --git a/drivers/media/dvb/frontends/dib8000.c b/drivers/media/dvb/frontends/dib8000.c index 7d2ea11..fe284d5 100644 --- a/drivers/media/dvb/frontends/dib8000.c +++ b/drivers/media/dvb/frontends/dib8000.c @@ -10,6 +10,8 @@ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/i2c.h> +#include <linux/mutex.h> + #include "dvb_math.h" #include "dvb_frontend.h" @@ -37,6 +39,7 @@ struct i2c_device { u8 addr; u8 *i2c_write_buffer; u8 *i2c_read_buffer; + struct mutex *i2c_buffer_lock; }; struct dib8000_state { @@ -77,6 +80,7 @@ struct dib8000_state { struct i2c_msg msg[2]; u8 i2c_write_buffer[4]; u8 i2c_read_buffer[2]; + struct mutex i2c_buffer_lock; }; enum dib8000_power_mode { @@ -86,24 +90,39 @@ enum dib8000_power_mode { static u16 dib8000_i2c_read16(struct i2c_device *i2c, u16 reg) { + u16 ret; struct i2c_msg msg[2] = { - {.addr = i2c->addr >> 1, .flags = 0, - .buf = i2c->i2c_write_buffer, .len = 2}, - {.addr = i2c->addr >> 1, .flags = I2C_M_RD, - .buf = i2c->i2c_read_buffer, .len = 2}, + {.addr = i2c->addr >> 1, .flags = 0, .len = 2}, + {.addr = i2c->addr >> 1, .flags = I2C_M_RD, .len = 2}, }; + if (mutex_lock_interruptible(i2c->i2c_buffer_lock) < 0) { + dprintk("could not acquire lock"); + return 0; + } + + msg[0].buf = i2c->i2c_write_buffer; msg[0].buf[0] = reg >> 8; msg[0].buf[1] = reg & 0xff; + msg[1].buf = i2c->i2c_read_buffer; if (i2c_transfer(i2c->adap, msg, 2) != 2) dprintk("i2c read error on %d", reg); - return (msg[1].buf[0] << 8) | msg[1].buf[1]; + ret = (msg[1].buf[0] << 8) | msg[1].buf[1]; + mutex_unlock(i2c->i2c_buffer_lock); + return ret; } static u16 dib8000_read_word(struct dib8000_state *state, u16 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 >> 8; state->i2c_write_buffer[1] = reg & 0xff; @@ -120,7 +139,10 @@ static u16 dib8000_read_word(struct dib8000_state *state, u16 reg) if (i2c_transfer(state->i2c.adap, state->msg, 2) != 2) dprintk("i2c read error on %d", reg); - return (state->i2c_read_buffer[0] << 8) | state->i2c_read_buffer[1]; + ret = (state->i2c_read_buffer[0] << 8) | state->i2c_read_buffer[1]; + mutex_unlock(&state->i2c_buffer_lock); + + return ret; } static u32 dib8000_read32(struct dib8000_state *state, u16 reg) @@ -135,22 +157,35 @@ static u32 dib8000_read32(struct dib8000_state *state, u16 reg) static int dib8000_i2c_write16(struct i2c_device *i2c, u16 reg, u16 val) { - struct i2c_msg msg = {.addr = i2c->addr >> 1, .flags = 0, - .buf = i2c->i2c_write_buffer, .len = 4}; + struct i2c_msg msg = {.addr = i2c->addr >> 1, .flags = 0, .len = 4}; int ret = 0; + if (mutex_lock_interruptible(i2c->i2c_buffer_lock) < 0) { + dprintk("could not acquire lock"); + return -EINVAL; + } + + msg.buf = i2c->i2c_write_buffer; msg.buf[0] = (reg >> 8) & 0xff; msg.buf[1] = reg & 0xff; msg.buf[2] = (val >> 8) & 0xff; msg.buf[3] = val & 0xff; ret = i2c_transfer(i2c->adap, &msg, 1) != 1 ? -EREMOTEIO : 0; + mutex_unlock(i2c->i2c_buffer_lock); return ret; } static int dib8000_write_word(struct dib8000_state *state, u16 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 >> 8) & 0xff; state->i2c_write_buffer[1] = reg & 0xff; state->i2c_write_buffer[2] = (val >> 8) & 0xff; @@ -162,7 +197,11 @@ static int dib8000_write_word(struct dib8000_state *state, u16 reg, u16 val) state->msg[0].buf = state->i2c_write_buffer; state->msg[0].len = 4; - return i2c_transfer(state->i2c.adap, state->msg, 1) != 1 ? -EREMOTEIO : 0; + ret = (i2c_transfer(state->i2c.adap, state->msg, 1) != 1 ? + -EREMOTEIO : 0); + mutex_unlock(&state->i2c_buffer_lock); + + return ret; } static const s16 coeff_2k_sb_1seg_dqpsk[8] = { @@ -2434,8 +2473,15 @@ int dib8000_i2c_enumeration(struct i2c_adapter *host, int no_of_demods, u8 defau if (!client.i2c_read_buffer) { dprintk("%s: not enough memory", __func__); ret = -ENOMEM; - goto error_memory; + goto error_memory_read; + } + client.i2c_buffer_lock = kzalloc(sizeof(struct mutex), GFP_KERNEL); + if (!client.i2c_buffer_lock) { + dprintk("%s: not enough memory", __func__); + ret = -ENOMEM; + goto error_memory_lock; } + mutex_init(client.i2c_buffer_lock); for (k = no_of_demods - 1; k >= 0; k--) { /* designated i2c address */ @@ -2476,8 +2522,10 @@ int dib8000_i2c_enumeration(struct i2c_adapter *host, int no_of_demods, u8 defau } error: + kfree(client.i2c_buffer_lock); +error_memory_lock: kfree(client.i2c_read_buffer); -error_memory: +error_memory_read: kfree(client.i2c_write_buffer); return ret; @@ -2581,6 +2629,8 @@ struct dvb_frontend *dib8000_attach(struct i2c_adapter *i2c_adap, u8 i2c_addr, s state->i2c.addr = i2c_addr; state->i2c.i2c_write_buffer = state->i2c_write_buffer; state->i2c.i2c_read_buffer = state->i2c_read_buffer; + mutex_init(&state->i2c_buffer_lock); + state->i2c.i2c_buffer_lock = &state->i2c_buffer_lock; state->gpio_val = cfg->gpio_val; state->gpio_dir = cfg->gpio_dir; |