6.18-stable review patch. If anyone has any objections, please let me know.
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From: Josua Mayer josua@solid-run.com
[ Upstream commit f0e6bc0c3ef4b4afb299bd6912586cafd5d864e9 ]
CP110 based platforms rely on the bootloader for pci port initialization. TF-A actively prevents non-uboot re-configuration of pci lanes, and many boards do not have software control over the pci card reset.
If a pci port had link at boot-time and the clock is stopped at a later point, the link fails and can not be recovered.
PCI controller driver probe - and by extension ownership of a driver for the pci clocks - may be delayed especially on large modular kernels, causing the clock core to start disabling unused clocks.
Add the CLK_IGNORE_UNUSED flag to the three pci port's clocks to ensure they are not stopped before the pci controller driver has taken ownership and tested for an existing link.
This fixes failed pci link detection when controller driver probes late, e.g. with arm64 defconfig and CONFIG_PHY_MVEBU_CP110_COMPHY=m.
Closes: https://lore.kernel.org/r/b71596c7-461b-44b6-89ab-3cfbd492639f@solid-run.com Signed-off-by: Josua Mayer josua@solid-run.com Reviewed-by: Andrew Lunn andrew@lunn.ch Signed-off-by: Gregory CLEMENT gregory.clement@bootlin.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clk/mvebu/cp110-system-controller.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/drivers/clk/mvebu/cp110-system-controller.c b/drivers/clk/mvebu/cp110-system-controller.c index 03c59bf22106..b47c86906046 100644 --- a/drivers/clk/mvebu/cp110-system-controller.c +++ b/drivers/clk/mvebu/cp110-system-controller.c @@ -110,6 +110,25 @@ static const char * const gate_base_names[] = { [CP110_GATE_EIP197] = "eip197" };
+static unsigned long gate_flags(const u8 bit_idx) +{ + switch (bit_idx) { + case CP110_GATE_PCIE_X1_0: + case CP110_GATE_PCIE_X1_1: + case CP110_GATE_PCIE_X4: + /* + * If a port had an active link at boot time, stopping + * the clock creates a failed state from which controller + * driver can not recover. + * Prevent stopping this clock till after a driver has taken + * ownership. + */ + return CLK_IGNORE_UNUSED; + default: + return 0; + } +}; + struct cp110_gate_clk { struct clk_hw hw; struct regmap *regmap; @@ -171,6 +190,7 @@ static struct clk_hw *cp110_register_gate(const char *name, init.ops = &cp110_gate_ops; init.parent_names = &parent_name; init.num_parents = 1; + init.flags = gate_flags(bit_idx);
gate->regmap = regmap; gate->bit_idx = bit_idx;