Re: [PATCH V2 17/21] RISC-V: time.c: Add ACPI support for time_init()

[Sunil V L]

On Mon, Feb 20, 2023 at 08:58:08PM +0100, Andrew Jones wrote:
> On Thu, Feb 16, 2023 at 11:50:39PM +0530, Sunil V L wrote:
> > On ACPI based platforms, timer related information is
> > available in RHCT. Add ACPI based probe support to the
> > timer initialization.
> > 
> > Signed-off-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx>
> > Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> > ---
> >  arch/riscv/kernel/time.c | 25 +++++++++++++++++++------
> >  1 file changed, 19 insertions(+), 6 deletions(-)
> > 
> > diff --git a/arch/riscv/kernel/time.c b/arch/riscv/kernel/time.c
> > index 1cf21db4fcc7..e49b897fc657 100644
> > --- a/arch/riscv/kernel/time.c
> > +++ b/arch/riscv/kernel/time.c
> > @@ -4,6 +4,7 @@
> >   * Copyright (C) 2017 SiFive
> >   */
> >  
> > +#include <linux/acpi.h>
> >  #include <linux/of_clk.h>
> >  #include <linux/clockchips.h>
> >  #include <linux/clocksource.h>
> > @@ -18,17 +19,29 @@ EXPORT_SYMBOL_GPL(riscv_timebase);
> >  void __init time_init(void)
> >  {
> >  	struct device_node *cpu;
> > +	struct acpi_table_rhct *rhct;
> > +	acpi_status status;
> >  	u32 prop;
> >  
> > -	cpu = of_find_node_by_path("/cpus");
> > -	if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
> > -		panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
> > -	of_node_put(cpu);
> > -	riscv_timebase = prop;
> > +	if (acpi_disabled) {
> > +		cpu = of_find_node_by_path("/cpus");
> > +		if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
> > +			panic("RISC-V system with no 'timebase-frequency' in DTS\n");
> > +		of_node_put(cpu);
> > +		riscv_timebase = prop;
> > +	} else {
> > +		status = acpi_get_table(ACPI_SIG_RHCT, 0, (struct acpi_table_header **)&rhct);
> > +		if (ACPI_FAILURE(status))
> > +			panic("RISC-V ACPI system with no RHCT table\n");
> > +		riscv_timebase = rhct->time_base_freq;
> > +		acpi_put_table((struct acpi_table_header *)rhct);
> > +	}
> >  
> >  	lpj_fine = riscv_timebase / HZ;
> >  
> > -	of_clk_init(NULL);
> > +	if (acpi_disabled)
> > +		of_clk_init(NULL);
> 
> I think we should be able to move of_clk_init() up into the acpi_disabled
> arm rather than add another if here.

Yes, will update.

Thanks,
Sunil