On 18/05/2022 12:35, Vladimir Zapolskiy wrote:
Access to I/O of SM8250 camera clock controller IP depends on enabled
GCC_CAMERA_AHB_CLK clock supplied by global clock controller, the latter
one is inited on subsys level, so, to satisfy the dependency, it would
make sense to deprive the init level of camcc-sm8250 driver.
Hi,
I believe this is due to the fact that this clock is falsely advertised
by the header and Linux does not know anything about it, because it is
handled by a magic write [1] (as I once said in a similar case, this was
going bite eventually..) instead and the index corresponding to the
define symbol is not initialized, hence it points to NULL. Adding the
clock properly in GCC would let the OF clock stuff handle it gracefully.
If that is the case, your patch disabling the clock controller block
(which I'm against unless there's abosolute need, as having the hw block
initialized properly should be possible regardless of the board, as it's
a generic SoC components) should not be necessary.
That said, I can not test my theory right now.
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/clk/qcom/gcc-sm8250.c?h=next-20220518#n3647
Konrad
If both drivers are compiled as built-in, there is a change that a board
won't boot up due to a race, which happens on the same init level.
Fixes: 5d66ca79b58c ("clk: qcom: Add camera clock controller driver for SM8250")
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
Tested-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
---
drivers/clk/qcom/camcc-sm8250.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)
diff --git a/drivers/clk/qcom/camcc-sm8250.c b/drivers/clk/qcom/camcc-sm8250.c
index 439eaafdcc86..ae4e9774f36e 100644
--- a/drivers/clk/qcom/camcc-sm8250.c
+++ b/drivers/clk/qcom/camcc-sm8250.c
@@ -2440,17 +2440,7 @@ static struct platform_driver cam_cc_sm8250_driver = {
},
};
-static int __init cam_cc_sm8250_init(void)
-{
- return platform_driver_register(&cam_cc_sm8250_driver);
-}
-subsys_initcall(cam_cc_sm8250_init);
-
-static void __exit cam_cc_sm8250_exit(void)
-{
- platform_driver_unregister(&cam_cc_sm8250_driver);
-}
-module_exit(cam_cc_sm8250_exit);
+module_platform_driver(cam_cc_sm8250_driver);
MODULE_DESCRIPTION("QTI CAMCC SM8250 Driver");
MODULE_LICENSE("GPL v2");
