Re: Clocks used by another OS/CPU

[Dirk Behme <dirk.behme@de.bosch.com>]

On 29.06.2017 13:56, Geert Uytterhoeven wrote:
> Hi Dirk,
> 
> On Thu, Jun 29, 2017 at 11:27 AM, Geert Uytterhoeven
> <geert@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