If power area D4, which contains the Coresight-ETM hardware block, is powered down on R-Mobile A1 (r8a7740), the kernel crashes when suspending from s2ram with: Internal error: Oops - undefined instruction: 0 [#1] ARM This happens because dbg_cpu_pm_notify() calls reset_ctrl_regs(), which can't access the debug registers as the debug module is powered down. Add a minimal device node for the Coresight-ETM hardware block, and hook it up to the D4 PM domain, so the R-Mobile System Controller driver can keep the arm_dbg_regs_available flag in sync with the state of the D4 PM domain. Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Cc: devicetree@xxxxxxxxxxxxxxx --- This is a fix on top of series "[PATCH 00/13] ARM: shmobile: R-Mobile: DT PM domain support" (https://lkml.org/lkml/2014/9/25/452), to be folded into "[PATCH v3 10/13] ARM: shmobile: r8a7740 dtsi: Add PM domain support" (https://lkml.org/lkml/2014/9/25/450). v2: - New --- arch/arm/boot/dts/r8a7740.dtsi | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm/boot/dts/r8a7740.dtsi b/arch/arm/boot/dts/r8a7740.dtsi index 0fb93df46af4ce08..2ae08fc99be678c3 100644 --- a/arch/arm/boot/dts/r8a7740.dtsi +++ b/arch/arm/boot/dts/r8a7740.dtsi @@ -44,6 +44,11 @@ interrupts = <0 83 IRQ_TYPE_LEVEL_HIGH>; }; + ptm { + compatible = "arm,coresight-etm3x"; + power-domains = <&pd_d4>; + }; + cmt1: timer@e6138000 { compatible = "renesas,cmt-48-r8a7740", "renesas,cmt-48"; reg = <0xe6138000 0x170>; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html