diff options
| author | Sakari Ailus <sakari.ailus@linux.intel.com> | 2017-08-16 03:28:16 -0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2017-08-20 08:33:46 -0400 |
| commit | 070ed82e32020dd9cc1ab3b5790b6b7d3f788e30 (patch) | |
| tree | 2e0d6f5f92a04dd3347c16d0a0f719401039f419 /drivers/media/i2c/et8ek8 | |
| parent | 392296208b952dfa486cfa44db72587efd960714 (diff) | |
media: et8ek8: Decrease stack usage
The et8ek8 driver combines I²C register writes to a single array that it
passes to i2c_transfer(). The maximum number of writes is 48 at once,
decrease it to 8 and make more transfers if needed.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'drivers/media/i2c/et8ek8')
| -rw-r--r-- | drivers/media/i2c/et8ek8/et8ek8_driver.c | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/drivers/media/i2c/et8ek8/et8ek8_driver.c b/drivers/media/i2c/et8ek8/et8ek8_driver.c index f39f5179dd95..c14f0fd6ded3 100644 --- a/drivers/media/i2c/et8ek8/et8ek8_driver.c +++ b/drivers/media/i2c/et8ek8/et8ek8_driver.c @@ -43,7 +43,7 @@ #define ET8EK8_NAME "et8ek8" #define ET8EK8_PRIV_MEM_SIZE 128 -#define ET8EK8_MAX_MSG 48 +#define ET8EK8_MAX_MSG 8 struct et8ek8_sensor { struct v4l2_subdev subdev; @@ -220,7 +220,8 @@ static void et8ek8_i2c_create_msg(struct i2c_client *client, u16 len, u16 reg, /* * A buffered write method that puts the wanted register write - * commands in a message list and passes the list to the i2c framework + * commands in smaller number of message lists and passes the lists to + * the i2c framework */ static int et8ek8_i2c_buffered_write_regs(struct i2c_client *client, const struct et8ek8_reg *wnext, @@ -231,11 +232,7 @@ static int et8ek8_i2c_buffered_write_regs(struct i2c_client *client, int wcnt = 0; u16 reg, data_length; u32 val; - - if (WARN_ONCE(cnt > ET8EK8_MAX_MSG, - ET8EK8_NAME ": %s: too many messages.\n", __func__)) { - return -EINVAL; - } + int rval; /* Create new write messages for all writes */ while (wcnt < cnt) { @@ -249,10 +246,21 @@ static int et8ek8_i2c_buffered_write_regs(struct i2c_client *client, /* Update write count */ wcnt++; + + if (wcnt < ET8EK8_MAX_MSG) + continue; + + rval = i2c_transfer(client->adapter, msg, wcnt); + if (rval < 0) + return rval; + + cnt -= wcnt; + wcnt = 0; } - /* Now we send everything ... */ - return i2c_transfer(client->adapter, msg, wcnt); + rval = i2c_transfer(client->adapter, msg, wcnt); + + return rval < 0 ? rval : 0; } /* |