On 29.06.2017 13:56, Geert Uytterhoeven wrote:

quoted

On Thu, Jun 29, 2017 at 11:27 AM, Geert Uytterhoeven
[off-list ref] wrote:

quoted

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.

quoted

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.