V4L/DVB (6027): Get rid of an ill-behaved msleep in i2c write

Configuring the OLPC camera requires something over 150 register
writes.  Unfortunately, querying the CAFE i2c controller too
soon after a write causes the hardware to flake.  The problem had
been "solved" with an msleep() call, but, between the number of
registers and how msleep() behaves, that resulted in a 3-second
delay on camera initialization.  Instead, we hand-code a wait for
the completion interrupt which avoids reading the status registers.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/media/video/ov7670.c b/drivers/media/video/ov7670.c
index f8f21ddd9843..c4c5bd67f795 100644
--- a/drivers/media/video/ov7670.c
+++ b/drivers/media/video/ov7670.c
@@ -416,7 +416,10 @@ static int ov7670_read(struct i2c_client *c, unsigned char reg,
 static int ov7670_write(struct i2c_client *c, unsigned char reg,
                 unsigned char value)
 {
-        return i2c_smbus_write_byte_data(c, reg, value);
+        int ret = i2c_smbus_write_byte_data(c, reg, value);
+        if (reg == REG_COM7 && (value & COM7_RESET))
+                msleep(2);  /* Wait for reset to run */
+        return ret;
 }