From e67f325e9cd67562b761e884680c0fec03a6f404 Mon Sep 17 00:00:00 2001 From: Matthew Hagan Date: Tue, 8 Jun 2021 19:59:06 +0100 Subject: net: stmmac: explicitly deassert GMAC_AHB_RESET We are currently assuming that GMAC_AHB_RESET will already be deasserted by the bootloader. However if this has not been done, probing of the GMAC will fail. To remedy this we must ensure GMAC_AHB_RESET has been deasserted prior to probing. v2 changes: - remove NULL condition check for stmmac_ahb_rst in stmmac_main.c - unwrap dev_err() message in stmmac_main.c - add PTR_ERR() around plat->stmmac_ahb_rst in stmmac_platform.c v3 changes: - add error pointer to dev_err() output - add reset_control_assert(stmmac_ahb_rst) in stmmac_dvr_remove - revert PTR_ERR() around plat->stmmac_ahb_rst since this is performed on the returned value of ret by the calling function Signed-off-by: Matthew Hagan Signed-off-by: David S. Miller --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 +++++ drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 6 ++++++ include/linux/stmmac.h | 1 + 3 files changed, 12 insertions(+) --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -5052,6 +5052,10 @@ int stmmac_dvr_probe(struct device *devi reset_control_reset(priv->plat->stmmac_rst); } + ret = reset_control_deassert(priv->plat->stmmac_ahb_rst); + if (ret == -ENOTSUPP) + dev_err(priv->device, "unable to bring out of ahb reset\n"); + /* Init MAC and get the capabilities */ ret = stmmac_hw_init(priv); if (ret) @@ -5260,6 +5264,7 @@ int stmmac_dvr_remove(struct device *dev phylink_destroy(priv->phylink); if (priv->plat->stmmac_rst) reset_control_assert(priv->plat->stmmac_rst); + reset_control_assert(priv->plat->stmmac_ahb_rst); pm_runtime_put(dev); pm_runtime_disable(dev); if (priv->hw->pcs != STMMAC_PCS_TBI && --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c @@ -616,6 +616,12 @@ stmmac_probe_config_dt(struct platform_d plat->stmmac_rst = NULL; } + plat->stmmac_ahb_rst = devm_reset_control_get_optional_shared( + &pdev->dev, "ahb"); + if (IS_ERR(plat->stmmac_ahb_rst)) + if (PTR_ERR(plat->stmmac_ahb_rst) == -EPROBE_DEFER) + goto error_hw_init; + return plat; error_hw_init: --- a/include/linux/stmmac.h +++ b/include/linux/stmmac.h @@ -192,6 +192,7 @@ struct plat_stmmacenet_data { unsigned int clk_ref_rate; s32 ptp_max_adj; struct reset_control *stmmac_rst; + struct reset_control *stmmac_ahb_rst; struct stmmac_axi *axi; int has_gmac4; bool has_sun8i;