net: sfp: return the number of written bytes for smbus single byte access

We expect the SFP write accessors to return the number of written bytes.
We fail to do so for single-byte smbus accesses, which may cause errors
when setting a module's high-power state and for some cotsworks modules.

Let's return the amount of written bytes, as expected.

Fixes: 7662abf4db94 ("net: phy: sfp: Add support for SMBus module access")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20260105151840.144552-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 6166e91963644d4e6c2cf012d329d41a44530ccb..84bef5099dda6f49d22c5c69fc6d94f9d6fa61a5 100644 (file)
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -765,7 +765,7 @@ static int sfp_smbus_byte_write(struct sfp *sfp, bool a2, u8 dev_addr,
                dev_addr++;
        }
 
-       return 0;
+       return data - (u8 *)buf;
 }
 
 static int sfp_i2c_configure(struct sfp *sfp, struct i2c_adapter *i2c)