[PATCH] i2c: octeon: Remove zero-length message support

Jan Glauber
2016-04-26T14:43:16Z

Zero-length message support (SMBUS QUICK or i2c) never worked with
the Octeon hardware. Disable SMBUS QUICK support and bail out in
case of a zero-length i2c request.

After this change 'i2c-detect -q' will return an error on Octeon but
the previously reported results were wrong anyway.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
drivers/i2c/busses/i2c-octeon.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 9f11e19..e8a65f5 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -837,9 +837,6 @@ static int octeon_i2c_read(struct octeon_i2c *i2c, int target,
int i, result, length = *rlength;
bool final_read = false;

- if (length < 1)
- return -EINVAL;
-
octeon_i2c_data_write(i2c, (target << 1) | 1);
octeon_i2c_ctl_write(i2c, TWSI_CTL_ENAB);

@@ -925,6 +922,12 @@ static int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
for (i = 0; ret == 0 && i < num; i++) {
struct i2c_msg *pmsg = &msgs[i];

+ /* zero-length messages are not supported */
+ if (!pmsg->len) {
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
ret = octeon_i2c_start(i2c);
if (ret)
return ret;
@@ -998,7 +1001,7 @@ static struct i2c_bus_recovery_info octeon_i2c_recovery_info = {

static u32 octeon_i2c_functionality(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
}

--
1.9.1