[PATCH net 1/4] net: pcs: mtk-lynxi: check regmap reads in mtk_pcs_lynxi_get_state()
From: Daniel Golle <daniel@makrotopia.org>
Date: 2026-07-30 16:03:41
Also in:
linux-arm-kernel, linux-mediatek, lkml
Subsystem:
ethernet phy library, mediatek ethernet pcs driver, networking drivers, the rest · Maintainers:
Andrew Lunn, Heiner Kallweit, Alexander Couzens, Daniel Golle, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
mtk_pcs_lynxi_get_state() ignores regmap_read()'s return value; a
failed read leaves bm and adv holding uninitialized stack values
which are then decoded into the reported link state. The regmaps
backing the MT7531 SGMII PCS instances sit on an MDIO bus where
reads can fail. Check both reads and leave the state untouched on
error.
Fixes: 4765a9722e09 ("net: pcs: add driver for MediaTek SGMII PCS")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
drivers/net/pcs/pcs-mtk-lynxi.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/pcs/pcs-mtk-lynxi.c b/drivers/net/pcs/pcs-mtk-lynxi.c
index a753bd88cbc2..454f2924831c 100644
--- a/drivers/net/pcs/pcs-mtk-lynxi.c
+++ b/drivers/net/pcs/pcs-mtk-lynxi.c@@ -113,8 +113,9 @@ static void mtk_pcs_lynxi_get_state(struct phylink_pcs *pcs, unsigned int bm, adv; /* Read the BMSR and LPA */ - regmap_read(mpcs->regmap, SGMSYS_PCS_CONTROL_1, &bm); - regmap_read(mpcs->regmap, SGMSYS_PCS_ADVERTISE, &adv); + if (regmap_read(mpcs->regmap, SGMSYS_PCS_CONTROL_1, &bm) || + regmap_read(mpcs->regmap, SGMSYS_PCS_ADVERTISE, &adv)) + return; phylink_mii_c22_pcs_decode_state(state, neg_mode, FIELD_GET(SGMII_BMSR, bm),
--
2.55.0