On 09.11.2020 13:32, Sylwester Nawrocki wrote:
> Hi Paweł,
>
> On 11/7/20 13:14, Paweł Chmiel wrote:
>> This clock must be always enabled to allow access to any registers in
>> fsys1 CMU. Until proper solution based on runtime PM is applied
>> (similar to what was done for Exynos5433), fix this by calling
>> clk_prepare_enable() directly from clock provider driver.
>>
>> It was observed on Samsung Galaxy S6 device (based on Exynos7420), where
>> UFS module is probed before pmic used to power that device.
>> In this case defer probe was happening and that clock was disabled by
>> UFS driver, causing whole boot to hang on next CMU access.
>>
>> Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@xxxxxxxxx>
>
>> --- a/drivers/clk/samsung/clk-exynos7.c
>> +++ b/drivers/clk/samsung/clk-exynos7.c
>
>> @@ -571,6 +572,10 @@ static const struct samsung_cmu_info top1_cmu_info __initconst = {
>> static void __init exynos7_clk_top1_init(struct device_node *np)
>> {
>> samsung_cmu_register_one(np, &top1_cmu_info);
>> + /*
>> + * Keep top FSYS1 aclk enabled permanently. It's required for CMU register access.
>> + */
>> + clk_prepare_enable(__clk_lookup("aclk_fsys1_200"));
>
> Thanks for the patch. Could you rework it to avoid the __clk_lookup() call?
> I.e. could you change it to something along the lines of:
Hi.
I'll send v3 version with this fixed.
Thanks for review and comments
>
> -------------8<----------------
> diff --git a/drivers/clk/samsung/clk-exynos7.c b/drivers/clk/samsung/clk-exynos7.c
> index 87ee1ba..9ecf498 100644
> --- a/drivers/clk/samsung/clk-exynos7.c
> +++ b/drivers/clk/samsung/clk-exynos7.c
> @@ -570,7 +570,15 @@ static const struct samsung_cmu_info top1_cmu_info __initconst = {
>
> static void __init exynos7_clk_top1_init(struct device_node *np)
> {
> - samsung_cmu_register_one(np, &top1_cmu_info);
> + struct samsung_clk_provider *ctx;
> + struct clk_hw **hws;
> +
> + ctx = samsung_cmu_register_one(np, &top1_cmu_info);
> + if (!ctx)
> + return;
> + hws = ctx->clk_data.hws;
> +
> + clk_prepare_enable(hws[CLK_ACLK_FSYS1_200]);
> }
>
> CLK_OF_DECLARE(exynos7_clk_top1, "samsung,exynos7-clock-top1",
> -------------8<----------------
> ?
>
> --
> Regards,
> Sylwester
>
>
