Re: [PATCH V4 13/23] RISC-V: cpufeature: Add ACPI support in riscv_fill_hwcap()

[Sunil V L]

On Sat, Apr 29, 2023 at 11:31:20AM +0100, Conor Dooley wrote:
> Hey Sunil,
> 
> On Tue, Apr 04, 2023 at 11:50:27PM +0530, Sunil V L wrote:
> 
> > @@ -103,14 +109,36 @@ void __init riscv_fill_hwcap(void)
> >  
> >  	bitmap_zero(riscv_isa, RISCV_ISA_EXT_MAX);
> >  
> > -	for_each_of_cpu_node(node) {
> > +	if (!acpi_disabled) {
> > +		status = acpi_get_table(ACPI_SIG_RHCT, 0, &rhct);
> > +		if (ACPI_FAILURE(status))
> > +			return;
> > +	}
> > +
> > +	for_each_possible_cpu(cpu) {
> >  		unsigned long this_hwcap = 0;
> >  		DECLARE_BITMAP(this_isa, RISCV_ISA_EXT_MAX);
> >  		const char *temp;
> >  
> > -		if (of_property_read_string(node, "riscv,isa", &isa)) {
> > -			pr_warn("Unable to find \"riscv,isa\" devicetree entry\n");
> > -			continue;
> > +		if (acpi_disabled) {
> > +			node = of_cpu_device_node_get(cpu);
> > +			if (node) {
> > +				rc = of_property_read_string(node, "riscv,isa", &isa);
> > +				of_node_put(node);
> > +				if (rc) {
> > +					pr_warn("Unable to find \"riscv,isa\" devicetree entry\n");
> > +					continue;
> > +				}
> > +			} else {
> > +				pr_warn("Unable to find cpu node\n");
> > +				continue;
> 
> I was poking at this the last few days and went back to look at the ACPI
> code again. Is there a reason we don't do early-return here? IOW:
> 
> 	node = of_cpu_device_node_get(cpu);
> 	if (!node) {
> 		pr_warn()
> 		continue;
> 	}
> 
> 	rc = of_property_read_string(node, "riscv,isa", &isa);
> 	of_node_put(node);
> 	if (rc) {
> 		pr_warn();
> 		continue;
> 	}
> 
This looks better. Will update when I send the next revision of the
series. Thank you!, Conor.