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Date:   Tue, 2 May 2023 06:58:07 +0530
From:   Sunil V L <sunilvl@ventanamicro.com>
To:     Conor Dooley <conor@kernel.org>
Cc:     linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-riscv@lists.infradead.org, linux-acpi@vger.kernel.org,
        linux-crypto@vger.kernel.org, platform-driver-x86@vger.kernel.org,
        llvm@lists.linux.dev, Jonathan Corbet <corbet@lwn.net>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>, Len Brown <lenb@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Weili Qian <qianweili@huawei.com>,
        Zhou Wang <wangzhou1@hisilicon.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Marc Zyngier <maz@kernel.org>,
        Maximilian Luz <luzmaximilian@gmail.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Mark Gross <markgross@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>,
        "Rafael J . Wysocki" <rafael@kernel.org>,
        "David S . Miller" <davem@davemloft.net>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Andrew Jones <ajones@ventanamicro.com>
Subject: Re: [PATCH V4 13/23] RISC-V: cpufeature: Add ACPI support in
 riscv_fill_hwcap()
Message-ID: <ZFBnJ/7TWTBpPZm0@sunil-laptop>
References: <20230404182037.863533-1-sunilvl@ventanamicro.com>
 <20230404182037.863533-14-sunilvl@ventanamicro.com>
 <20230429-voucher-tutor-715fd4f6c24e@spud>
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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.