Re: [PATCH 3/5] ARM: dts: Add basic support for EcoNet EN7523

On Wed, Aug 04, 2021 at 06:41:55PM +0200, Bert Vermeulen wrote:

On 7/30/21 4:46 PM, Mark Rutland wrote:

quoted

On Fri, Jul 30, 2021 at 03:45:50PM +0200, Bert Vermeulen wrote:

quoted

+	timer {
+		compatible = "arm,armv8-timer";

This should be "arm,armv7-timer".

quoted

+		interrupt-parent = <&gic>;
+		interrupts = <GIC_PPI 13 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>,
+			     <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_LOW)>;

GICv3 doesn't have a cpumask in its PPI description, so the
GIC_CPU_MASK_SIMPLE() bits should be removed.

Ok, will fix.

quoted

quoted

+		clock-frequency = <25000000>;

Please have your FW configure CNTFRQ on each CPU; the clock-frequency
property in the DT is a workaround for broken FW, and it's *vastly*
preferable for FW to configure this correctly (e.g. as it means VMs
should "just work").

I've since got hold of the modified U-Boot that runs on my eval board, and
indeed it doesn't set CNTFRQ. So the kernel does need this, for the moment.

Can't you write CNTFRQ in the u-boot shell/script?

I may get a chance to upstream support for this SoC in U-Boot, but I can't
control what people are going to ship with their board. Is it ok to leave
this in?

If they want a working upstream Linux, then you can control it.

I seem to recall this being rejected in other cases. That may have been 
on v8 which has taken stricter stances (but arguably any new v7 stuff 
should too).

Rob