net: stmmac: dwmac-stm32: Add test to verify if ETHCK is used before checking clk...

When we want to use clock from RCC to clock Ethernet PHY (with ETHCK)
we need to check if value of clock rate is authorized.
If ETHCK is unused, the ETHCK frequency is 0Hz and validation fails.
It makes no sense to validate unused ETHCK, so skip the validation.

Fixes: 582ac134963e ("net: stmmac: dwmac-stm32: Separate out external clock rate validation")
Signed-off-by: Christophe Roullier <christophe.roullier@foss.st.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Tested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
index 23cf0a5b047f7f341bc8554162ecac88e8ee8c65..d6a268237ca168d01a79b9ed8afd400abb307282 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
@@ -206,6 +206,9 @@ static int stm32mp1_validate_ethck_rate(struct plat_stmmacenet_data *plat_dat)
        struct stm32_dwmac *dwmac = plat_dat->bsp_priv;
        const u32 clk_rate = clk_get_rate(dwmac->clk_eth_ck);
 
+       if (!dwmac->enable_eth_ck)
+               return 0;
+
        switch (plat_dat->mac_interface) {
        case PHY_INTERFACE_MODE_MII:
        case PHY_INTERFACE_MODE_GMII: