On 23. 5. 18. 16:44, Marek Szyprowski wrote:
> Commit adf8238ef403 ("ARM: dts: exynos: move exynos-bus nodes out of soc
> in Exynos4412") changed the order of the exynos-bus nodes, what results
> in different probe order of the Exynos Bus devices. Although the driver
> properly handles the deferred probe and all devices seems to be finally
> properly registered, this change revealed some kind of a bug related to
> PPMU counters registration and passive governor operation. Usually in 1
> of 10 boots this results in complete board freeze during loading of the
> kernel modules.
>
> To avoid that freeze, ensure that the Exynos PPMU driver is already
> loaded before the Exynos Bus driver starts probing.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> ---
> This is a follow-up of the following discussion:
> https://lore.kernel.org/all/d287ca9f-b056-d39a-aa93-b0e2cb279f73@xxxxxxxxxx/
> ---
> drivers/devfreq/exynos-bus.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
> index 88414445adf3..245898f1a88e 100644
> --- a/drivers/devfreq/exynos-bus.c
> +++ b/drivers/devfreq/exynos-bus.c
> @@ -518,6 +518,7 @@ static struct platform_driver exynos_bus_platdrv = {
> };
> module_platform_driver(exynos_bus_platdrv);
>
> +MODULE_SOFTDEP("pre: exynos_ppmu");
> MODULE_DESCRIPTION("Generic Exynos Bus frequency driver");
> MODULE_AUTHOR("Chanwoo Choi <cw00.choi@xxxxxxxxxxx>");
> MODULE_LICENSE("GPL v2");
Applied it. Thanks.
--
Best Regards,
Samsung Electronics
Chanwoo Choi
