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[media] em28xx-i2c: Add a read after I2C write 

All I2C logs we got for em28xx does that. With Terratec H5, at
400MHz speed, it seems that this is required, to avoid having
troubles at the I2C bus.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Mauro Carvalho Chehab 2011-07-09 19:36:11 -03:00
parent e4f4f8758b
commit bbc70e647b
1 changed files with 10 additions and 1 deletions
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11
drivers/media/video/em28xx/em28xx-i2c.c
View File

@ -181,16 +181,25 @@ static int em2800_i2c_recv_bytes(struct em28xx *dev, unsigned char addr,
/*
* em28xx_i2c_send_bytes()
* untested for more than 4 bytes
*/
static int em28xx_i2c_send_bytes(void *data, unsigned char addr, char *buf,
short len, int stop)
{
int wrcount = 0;
struct em28xx *dev = (struct em28xx *)data;
int write_timeout, ret;
wrcount = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);
/* Seems to be required after a write */
for (write_timeout = EM2800_I2C_WRITE_TIMEOUT; write_timeout > 0;
write_timeout -= 5) {
ret = dev->em28xx_read_reg(dev, 0x05);
if (!ret)
break;
msleep(5);
}
return wrcount;
}