[media] DiBxxxx: get rid of DMA buffer on stack
This patch removes the remaining on-stack buffer for USB DMA transfer.
This patch also reduces the stack memory usage.
Cc: stable@kernel.org
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>
diff --git a/drivers/media/dvb/frontends/dib7000p.c b/drivers/media/dvb/frontends/dib7000p.c
index 900af60..0c9f40c 100644
--- a/drivers/media/dvb/frontends/dib7000p.c
+++ b/drivers/media/dvb/frontends/dib7000p.c
@@ -63,6 +63,11 @@
u16 tuner_enable;
struct i2c_adapter dib7090_tuner_adap;
+
+ /* for the I2C transfer */
+ struct i2c_msg msg[2];
+ u8 i2c_write_buffer[4];
+ u8 i2c_read_buffer[2];
};
enum dib7000p_power_mode {
@@ -76,29 +81,39 @@
static u16 dib7000p_read_word(struct dib7000p_state *state, u16 reg)
{
- u8 wb[2] = { reg >> 8, reg & 0xff };
- u8 rb[2];
- struct i2c_msg msg[2] = {
- {.addr = state->i2c_addr >> 1, .flags = 0, .buf = wb, .len = 2},
- {.addr = state->i2c_addr >> 1, .flags = I2C_M_RD, .buf = rb, .len = 2},
- };
+ state->i2c_write_buffer[0] = reg >> 8;
+ state->i2c_write_buffer[1] = reg & 0xff;
- if (i2c_transfer(state->i2c_adap, msg, 2) != 2)
+ memset(state->msg, 0, 2 * sizeof(struct i2c_msg));
+ state->msg[0].addr = state->i2c_addr >> 1;
+ state->msg[0].flags = 0;
+ state->msg[0].buf = state->i2c_write_buffer;
+ state->msg[0].len = 2;
+ state->msg[1].addr = state->i2c_addr >> 1;
+ state->msg[1].flags = I2C_M_RD;
+ state->msg[1].buf = state->i2c_read_buffer;
+ state->msg[1].len = 2;
+
+ if (i2c_transfer(state->i2c_adap, state->msg, 2) != 2)
dprintk("i2c read error on %d", reg);
- return (rb[0] << 8) | rb[1];
+ return (state->i2c_read_buffer[0] << 8) | state->i2c_read_buffer[1];
}
static int dib7000p_write_word(struct dib7000p_state *state, u16 reg, u16 val)
{
- u8 b[4] = {
- (reg >> 8) & 0xff, reg & 0xff,
- (val >> 8) & 0xff, val & 0xff,
- };
- struct i2c_msg msg = {
- .addr = state->i2c_addr >> 1, .flags = 0, .buf = b, .len = 4
- };
- return i2c_transfer(state->i2c_adap, &msg, 1) != 1 ? -EREMOTEIO : 0;
+ state->i2c_write_buffer[0] = (reg >> 8) & 0xff;
+ state->i2c_write_buffer[1] = reg & 0xff;
+ state->i2c_write_buffer[2] = (val >> 8) & 0xff;
+ state->i2c_write_buffer[3] = val & 0xff;
+
+ memset(&state->msg[0], 0, sizeof(struct i2c_msg));
+ state->msg[0].addr = state->i2c_addr >> 1;
+ state->msg[0].flags = 0;
+ 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;
}
static void dib7000p_write_tab(struct dib7000p_state *state, u16 * buf)
@@ -1550,11 +1565,24 @@
int dib7000pc_detection(struct i2c_adapter *i2c_adap)
{
- u8 tx[2], rx[2];
+ u8 *tx, *rx;
struct i2c_msg msg[2] = {
- {.addr = 18 >> 1, .flags = 0, .buf = tx, .len = 2},
- {.addr = 18 >> 1, .flags = I2C_M_RD, .buf = rx, .len = 2},
+ {.addr = 18 >> 1, .flags = 0, .len = 2},
+ {.addr = 18 >> 1, .flags = I2C_M_RD, .len = 2},
};
+ int ret = 0;
+
+ tx = kzalloc(2*sizeof(u8), GFP_KERNEL);
+ if (!tx)
+ return -ENOMEM;
+ rx = kzalloc(2*sizeof(u8), GFP_KERNEL);
+ if (!rx) {
+ goto rx_memory_error;
+ ret = -ENOMEM;
+ }
+
+ msg[0].buf = tx;
+ msg[1].buf = rx;
tx[0] = 0x03;
tx[1] = 0x00;
@@ -1574,7 +1602,11 @@
}
dprintk("-D- DiB7000PC not detected");
- return 0;
+
+ kfree(rx);
+rx_memory_error:
+ kfree(tx);
+ return ret;
}
EXPORT_SYMBOL(dib7000pc_detection);