diff mbox

i2c: octeon: Remove zero-length message support

Message ID 1461680812-10237-1-git-send-email-jglauber@cavium.com
State Accepted
Headers show

Commit Message

Jan Glauber April 26, 2016, 2:26 p.m. UTC 
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(-)

Comments

Wolfram Sang April 26, 2016, 9:04 p.m. UTC | #1 
On Tue, Apr 26, 2016 at 04:26:52PM +0200, Jan Glauber wrote:
> 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>

Applied to for-next, thanks!
diff mbox

Patch

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;
 }