[PATCH net v4 02/15] net: stmmac: reuse the MDIO reset GPIO on resume
flat view
COOLING11d
From: James Hilliard <hidden>
Date: 2026-09-26 15:49:25
Also in:
bpf, linux-sunxi, linux-tegra, lkml
Subsystem:
networking drivers, stmmac ethernet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Maxime Chevallier, Linus Torvalds
MDIO bus registration acquires the optional snps,reset GPIO through
devres. A later bus reset must reuse that descriptor: requesting the
same exclusive GPIO again returns -EBUSY while devres still owns it.
Cache the successfully acquired descriptor for subsequent resets.
Propagate acquisition errors without caching an error pointer.
Fixes: 7c86f20d15b7 ("net: stmmac: use GPIO descriptors in stmmac_mdio_reset")
Signed-off-by: James Hilliard <redacted>
---
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 +
drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 18 ++++++++++++------
2 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 7582fca63741..c7c876408d85 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h@@ -287,6 +287,7 @@ struct stmmac_priv { unsigned int pause_time; struct mii_bus *mii; + struct gpio_desc *mdio_reset_gpio; struct stmmac_pcs *integrated_pcs;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index afe98ff5bdcb..07d5eab05996 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c@@ -386,14 +386,20 @@ int stmmac_mdio_reset(struct mii_bus *bus) #ifdef CONFIG_OF if (priv->device->of_node) { - struct gpio_desc *reset_gpio; + struct gpio_desc *reset_gpio = priv->mdio_reset_gpio; u32 delays[3] = { 0, 0, 0 }; - reset_gpio = devm_gpiod_get_optional(priv->device, - "snps,reset", - GPIOD_OUT_LOW); - if (IS_ERR(reset_gpio)) - return PTR_ERR(reset_gpio); + /* The bus reset also runs on resume. Devres retains the GPIO + * until unbind, so do not request an already owned line again. + */ + if (!reset_gpio) { + reset_gpio = devm_gpiod_get_optional(priv->device, + "snps,reset", + GPIOD_OUT_LOW); + if (IS_ERR(reset_gpio)) + return PTR_ERR(reset_gpio); + priv->mdio_reset_gpio = reset_gpio; + } device_property_read_u32_array(priv->device, "snps,reset-delays-us",
--
2.53.0