Re: [PATCH v2 4/4] ARM: debug: qcom: add UART addresses to Kconfig help

From: Matthias Brugger
Date: Thu May 29 2014 - 11:28:01 EST


2014-05-27 14:05 GMT+02:00 Georgi Djakov <gdjakov@xxxxxxxxxx>:
> On 05/26/2014 08:17 PM, Matthias Brugger wrote:
>> 2014-05-26 15:45 GMT+02:00 Georgi Djakov <gdjakov@xxxxxxxxxx>:
>>> On 23.05.14, 19:39, Matthias Brugger wrote:
>>>>
>>>> 2014-05-23 17:12 GMT+02:00 Georgi Djakov <gdjakov@xxxxxxxxxx>:
>>>>>
>>>>> Add information about the APQ8084 debug UART physical and virtual
>>>>> addresses in the DEBUG_QCOM_UARTDM Kconfig help section.
>>>>> Requires: https://lkml.org/lkml/2014/4/14/312
>>>>>
>>>>> Signed-off-by: Georgi Djakov <gdjakov@xxxxxxxxxx>
>>>>> ---
>>>>> arch/arm/Kconfig.debug | 1 +
>>>>> 1 file changed, 1 insertion(+)
>>>>>
>>>>> diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
>>>>> index 40ee328..e71723d 100644
>>>>> --- a/arch/arm/Kconfig.debug
>>>>> +++ b/arch/arm/Kconfig.debug
>>>>> @@ -376,6 +376,7 @@ choice
>>>>> their output to the serial port on Qualcomm devices.
>>>>>
>>>>> ARCH DEBUG_UART_PHYS DEBUG_UART_BASE
>>>>> + APQ8084 0xf995e000 0xfa75e000
>>>>> MSM8X60 0x19c40000 0xf0040000
>>>>> MSM8960 0x16440000 0xf0040000
>>>>> MSM8974 0xf991e000 0xfa71e000
>>>>
>>>>
>>>> You don't have any uart defined in your dts. You should add them
>>>> before any adding low level debug support.
>>>> Otherwise there might be problems in booting a multi-platform kernel.
>>>>
>>>
>>> Thanks for the comment! As the uart depends on clocks, i am adding it to the
>>> dts as part of my global clock controller patchset [1].
>>> In this patch i am just adding some information to the help section.
>>> Do you see any problem with this?
>>
>> Are the patches for the clock controller applied already?
>> If not, I would consider to add this patch to clock controller series.
>>
>
> No, they are not applied yet. The uart dts definition depends on clocks, but the
> DEBUG_LL support does not. And the DEBUG_LL support is already there as it is
> common with other SoCs. I am sorry, but i don't see dependency between the dts
> definition and this patch. Could you explain please?

IMHO the dependancy is that DEBUG_LL uses the uart device, and this is
added when you add the dts.
AFAIK there can arise problems with multi-platform kernels if the uart
is not present.

>
> Thanks,
> Georgi
>



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