From ffba2123e1714a27e9362fda57c42155dda37efc Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Tue, 22 Mar 2022 20:32:55 -0700 Subject: [PATCH] net: stmmac: dwmac-qcom-ethqos: Enable RGMII functional clock on resume When the Qualcomm ethqos driver is properly described in its associated GDSC power-domain, the hardware will be powered down and loose its state between qcom_ethqos_probe() and stmmac_init_dma_engine(). The result of this is that the functional clock from the RGMII IO macro is no longer provides and the DMA software reset in dwmac4_dma_reset() will time out, due to lacking clock signal. Re-enable the functional clock, as part of the Qualcomm specific clock enablement sequence to avoid this problem. The final clock configuration will be adjusted by ethqos_fix_mac_speed() once the link is being brought up. Fixes: a7c30e62d4b8 ("net: stmmac: Add driver for Qualcomm ethqos") Signed-off-by: Bjorn Andersson Tested-and-reviewed-by: Bhupesh Sharma Link: https://lore.kernel.org/r/20220323033255.2282930-1-bjorn.andersson@linaro.org Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c index 0cc28c79cc61..835caa15d55f 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c @@ -487,6 +487,13 @@ static int ethqos_clks_config(void *priv, bool enabled) dev_err(ðqos->pdev->dev, "rgmii_clk enable failed\n"); return ret; } + + /* Enable functional clock to prevent DMA reset to timeout due + * to lacking PHY clock after the hardware block has been power + * cycled. The actual configuration will be adjusted once + * ethqos_fix_mac_speed() is invoked. + */ + ethqos_set_func_clk_en(ethqos); } else { clk_disable_unprepare(ethqos->rgmii_clk); } -- 2.11.0