[PATCH 6.6 051/105] net: usb: lan78xx: fix use of improperly initialized dev->chipid in lan78xx_reset

Greg Kroah-Hartman
2025-10-21T19:54:59Z

From: I Viswanath <viswanathiyyappan@gmail.com>

[ Upstream commit 8d93ff40d49d70e05c82a74beae31f883fe0eaf8 ]

dev->chipid is used in lan78xx_init_mac_address before it's initialized:

lan78xx_reset() {
lan78xx_init_mac_address()
lan78xx_read_eeprom()
lan78xx_read_raw_eeprom() <- dev->chipid is used here

dev->chipid = ... <- dev->chipid is initialized correctly here
}

Reorder initialization so that dev->chipid is set before calling
lan78xx_init_mac_address().

Fixes: a0db7d10b76e ("lan78xx: Add to handle mux control per chip id")
Signed-off-by: I Viswanath <viswanathiyyappan@gmail.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Khalid Aziz <khalid@kernel.org>
Link: https://patch.msgid.link/20251013181648.35153-1-viswanathiyyappan@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/usb/lan78xx.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 712530d6738fa..121f1c15c6793 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2928,10 +2928,6 @@ static int lan78xx_reset(struct lan78xx_net *dev)
}
} while (buf & HW_CFG_LRST_);

- ret = lan78xx_init_mac_address(dev);
- if (ret < 0)
- return ret;
-
/* save DEVID for later usage */
ret = lan78xx_read_reg(dev, ID_REV, &buf);
if (ret < 0)
@@ -2940,6 +2936,10 @@ static int lan78xx_reset(struct lan78xx_net *dev)
dev->chipid = (buf & ID_REV_CHIP_ID_MASK_) >> 16;
dev->chiprev = buf & ID_REV_CHIP_REV_MASK_;

+ ret = lan78xx_init_mac_address(dev);
+ if (ret < 0)
+ return ret;
+
/* Respond to the IN token with a NAK */
ret = lan78xx_read_reg(dev, USB_CFG0, &buf);
if (ret < 0)
--
2.51.0