Re: Clocks used by another OS/CPU

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On 29.06.2017 13:56, Geert Uytterhoeven wrote:
Hi Dirk,

On Thu, Jun 29, 2017 at 11:27 AM, Geert Uytterhoeven
<geert@xxxxxxxxxxxxxx> 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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