[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/dib7000m.c b/drivers/media/dvb/frontends/dib7000m.c
index 289a798..79cb1c2 100644
--- a/drivers/media/dvb/frontends/dib7000m.c
+++ b/drivers/media/dvb/frontends/dib7000m.c
@@ -50,6 +50,11 @@
u16 revision;
u8 agc_state;
+
+ /* for the I2C transfer */
+ struct i2c_msg msg[2];
+ u8 i2c_write_buffer[4];
+ u8 i2c_read_buffer[2];
};
enum dib7000m_power_mode {
@@ -64,29 +69,39 @@
static u16 dib7000m_read_word(struct dib7000m_state *state, u16 reg)
{
- u8 wb[2] = { (reg >> 8) | 0x80, 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) | 0x80;
+ 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 dib7000m_write_word(struct dib7000m_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 dib7000m_write_tab(struct dib7000m_state *state, u16 *buf)
{