Re: [PATCH 2/3] ARM: dts: Update the parent for Audss clocks in Exynos5420

[Kevin Hilman]

Tushar Behera <trblinux@xxxxxxxxx> writes:

> On Thu, Jun 26, 2014 at 4:51 AM, Kevin Hilman <khilman@xxxxxxxxxx> wrote:
>> Doug Anderson <dianders@xxxxxxxxxx> writes:
>>
>>> Tushar,
>>>
>>> On Tue, Jun 10, 2014 at 10:32 PM, Tushar Behera <tushar.b@xxxxxxxxxxx> wrote:
>>>> Currently CLK_FOUT_EPLL was set as one of the parents of AUDSS mux.
>>>> As per the user manual, it should be CLK_MAU_EPLL.
>>>>
>>>> The problem surfaced when the bootloader in Peach-pit board set
>>>> the EPLL clock as the parent of AUDSS mux. While booting the kernel,
>>>> we used to get a system hang during late boot if CLK_MAU_EPLL was
>>>> disabled.
>>>>
>>>> Signed-off-by: Tushar Behera <tushar.b@xxxxxxxxxxx>
>>>> Signed-off-by: Shaik Ameer Basha <shaik.ameer@xxxxxxxxxxx>
>>>> Reported-by: Kevin Hilman <khilman@xxxxxxxxxx>
>>>> ---
>>>>  arch/arm/boot/dts/exynos5420.dtsi |    2 +-
>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> I've tested this myself now as well.
>>>
>>> Tested-by: Doug Anderson <dianders@xxxxxxxxxxxx>
>>
>> For me, this patch alone (on top of -next) doesn't solve the boot hang.
>> I still need clk_ignore_unused for a successful boot.
>>
>> So, this patch might be correct, but it doesn't prevent a boot hang
>> using a chain-loaded nv_uboot on peach-pi.  There's still another clock
>> being disabled that causes a hang.
>>
>> Kevin
>
> Kevin,
>
> Can you please check if adding patch 1/3 alongwith patch 2/3 fixes the
> issue for you?

Yes, using patch 1/3 along with 2/3 fixes the issue.

> Also can you please confirm that setting CLK_IGNORE_UNUSED flag
> CLK_MAU_EPLL alone fixes the issue, without any need for
> clk_ignore_unused in u-boot bootargs?

Yes, I have this patch[1] in my local branch which fixes the issue
alone, without clk_ignore_unused on the command line.

Kevin


[1]