[PATCH 00/13] Enable CoreSight for the Ux500

Ulf Hansson ulf.hansson at linaro.org
Fri Apr 24 08:31:33 PDT 2015


On 24 April 2015 at 16:53, Ivan T. Ivanov <iivanov at mm-sol.com> wrote:
>
> On Fri, 2015-04-17 at 10:58 +0200, Linus Walleij wrote:
>> This patch series enables the CoreSight blocks for the Ux500.
>>
>> To do so I ran into a few obstacles, all resolved in this
>> series:
>>
>> - The Ux500 have two distinct clocks clocking the CS blocks,
>>   APETRACECLK clocking the AHB interconnect, what is usually
>>   referred to as "apb_pclk" in the AMBA primecell abstraction
>>   layer, and another clock called APEATCLK which is connected
>>   to the actual ATCLK on the CS blocks. So I have to add
>>   handling for this second clock as only the PCLK is handled
>>   today.
>>
>> - Doing so I need to use runtime PM, and I discovered that
>>   the current CS drivers go in and grab the PCLK from the
>>   AMBA primecell abstraction which is wrong: this shall be
>>   handled using runtime PM callbacks, see e.g.
>>   drivers/mmc/host/mmci.c. So I made a patch series fixing
>>   this. This also fixes the problem that the PCLK is left
>>   on since none of the drivers call pm_runtime_put() so
>>   the AMBA core can disable the PCLK, instead they are
>>   poking around with the PCLK themselves which is wrong.
>
> Probably stupid question, but.. How this is
> supposed to work if CONFIG_PM is not enabled?

The clock(s) will stay enabled after ->probe().

Kind regards
Uffe



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