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

From: Maxime Chevallier

Date: Mon Jan 05 2026 - 10:19:53 EST


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@xxxxxxxxxxx>
---
drivers/net/phy/sfp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 6166e9196364..84bef5099dda 100644
--- 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)
--
2.49.0