diff options
| author | Florian Fainelli <florian.fainelli@broadcom.com> | 2025-07-30 13:25:33 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-15 16:39:25 +0200 |
| commit | c3abe37ab41982f38096284e55dde7239c4bdf66 (patch) | |
| tree | e8e6bb6ea32f9d798eabd99451ab6c1fd6bb8cf7 | |
| parent | ee851768e4b8371ce151fd446d24bf3ae2d18789 (diff) | |
net: mdio: mdio-bcm-unimac: Correct rate fallback logic
[ 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.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/net/mdio/mdio-bcm-unimac.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/net/mdio/mdio-bcm-unimac.c b/drivers/net/mdio/mdio-bcm-unimac.c index b6e30bdf5325..7baab230008a 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) { |