Clocks used by another OS/CPU
Dirk Behme
dirk.behme at de.bosch.com
Thu Jun 29 05:07:38 PDT 2017
On 29.06.2017 13:56, Geert Uytterhoeven wrote:
> Hi Dirk,
>
> On Thu, Jun 29, 2017 at 11:27 AM, Geert Uytterhoeven
> <geert at linux-m68k.org> wrote:
>> CC clock, ARM, DT, PM people
>>
>> TL;DR: Clocks may be in use by another CPU not running Linux, while Linux
>> disables them as being unused.
>
>> Of course this is not limited to clocks, but also to e.g. PM domains.
>
> BTW, how do you prevent Linux from powering down the CR7 PM domain,
> which contains the Cortex R7?
The idea is
--- a/drivers/soc/renesas/r8a7795-sysc.c
+++ b/drivers/soc/renesas/r8a7795-sysc.c
@@ -38,7 +38,8 @@ static const struct rcar_sysc_area r8a7795_areas[]
__initconst = {
{ "ca53-cpu3", 0x200, 3, R8A7795_PD_CA53_CPU3, R8A7795_PD_CA53_SCU,
PD_CPU_NOCR },
{ "a3vp", 0x340, 0, R8A7795_PD_A3VP, R8A7795_PD_ALWAYS_ON },
- { "cr7", 0x240, 0, R8A7795_PD_CR7, R8A7795_PD_ALWAYS_ON },
+ { "cr7", 0x240, 0, R8A7795_PD_CR7, R8A7795_PD_ALWAYS_ON,
+ PD_CPU_NOCR },
{ "a3vc", 0x380, 0, R8A7795_PD_A3VC, R8A7795_PD_ALWAYS_ON },
{ "a2vc0", 0x3c0, 0, R8A7795_PD_A2VC0, R8A7795_PD_A3VC },
{ "a2vc1", 0x3c0, 1, R8A7795_PD_A2VC1, R8A7795_PD_A3VC },
Not finally tested, though.
Best regards
Dirk
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