6.15-stable review patch. If anyone has any objections, please let me know.
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From: Florian Fainelli florian.fainelli@broadcom.com
[ Upstream commit a81649a4efd382497bf3d34a623360263adc6993 ]
When the parent clock is a gated clock which has multiple parents, the clock provider (clk-scmi typically) might return a rate of 0 since there is not one of those particular parent clocks that should be chosen for returning a rate. Prior to ee975351cf0c ("net: mdio: mdio-bcm-unimac: Manage clock around I/O accesses"), we would not always be passing a clock reference depending upon how mdio-bcm-unimac was instantiated. In that case, we would take the fallback path where the rate is hard coded to 250MHz.
Make sure that we still fallback to using a fixed rate for the divider calculation, otherwise we simply ignore the desired MDIO bus clock frequency which can prevent us from interfacing with Ethernet PHYs properly.
Fixes: ee975351cf0c ("net: mdio: mdio-bcm-unimac: Manage clock around I/O accesses") Signed-off-by: Florian Fainelli florian.fainelli@broadcom.com Reviewed-by: Andrew Lunn andrew@lunn.ch Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20250730202533.3463529-1-florian.fainelli@broadcom.... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/mdio/mdio-bcm-unimac.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/net/mdio/mdio-bcm-unimac.c b/drivers/net/mdio/mdio-bcm-unimac.c index 074d96328f41..60565e7c88bd 100644 --- a/drivers/net/mdio/mdio-bcm-unimac.c +++ b/drivers/net/mdio/mdio-bcm-unimac.c @@ -209,10 +209,9 @@ static int unimac_mdio_clk_set(struct unimac_mdio_priv *priv) if (ret) return ret;
- if (!priv->clk) + rate = clk_get_rate(priv->clk); + if (!rate) rate = 250000000; - else - rate = clk_get_rate(priv->clk);
div = (rate / (2 * priv->clk_freq)) - 1; if (div & ~MDIO_CLK_DIV_MASK) {