Re: [PATCH V2] ARM: imx: add smp support for imx7d

On Sun, Jan 17, 2021 at 07:46:20PM +0800, Shawn Guo wrote:

On Thu, Jan 07, 2021 at 01:31:57PM +0100, Marek Vasut wrote:

quoted

From: Anson Huang <redacted>

Add SMP support for i.MX7D, including CPU hotplug support, for
systems where TFA is not present.

The arm,cpu-registers-not-fw-configured is required, otherwise the
timer does not work correctly.

As DT change becomes another patch, this should be dropped.

quoted

Signed-off-by: Anson Huang <redacted>
Signed-off-by: Arulpandiyan Vadivel <redacted> # Fix merge conflicts
Signed-off-by: Leonard Crestez <redacted>
Signed-off-by: Marek Vasut <marex@denx.de> # heavy cleanup

Checkpatch warnings:

WARNING: usage of NR_CPUS is often wrong - consider using cpu_possible(), num_possible_cpus(), for_each_possible_cpu(), etc
#151: FILE: arch/arm/mach-imx/platsmp.c:108:
+	for (i = ncores; i < NR_CPUS; i++)

False. This is initialising the cpu possible map, so can't use
cpu_possible().

quoted

+void imx_gpcv2_set_m_core_pgc(bool enable, u32 offset)

static inline?

Only "static" not "static inline" in a .c file.

quoted

+void __init imx7_src_init(void)
+{
+	struct device_node *np;
+	gpr_v2 = true;
+
+	np = of_find_compatible_node(NULL, NULL, "fsl,imx7d-src");
+	if (!np)
+		return;
+	src_base = of_iomap(np, 0);
+	WARN_ON(!src_base);

Don't we need of_node_put()?

I always worry about this. The resources of the node remains in use
after the initialisation function has completed, so why _shouldn't_
the node also have a reference to it - in the same way that any
bound driver effectively maintains a reference on its DT node for
its lifetime. The only difference is that system devices such as this
have a lifetime of the system.

It's not like you could drop the "fsl,imx7d-src" node at runtime and
the system will do the right thing.

-- 
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