From mboxrd@z Thu Jan 1 00:00:00 1970 From: guohanjun@huawei.com (Hanjun Guo) Date: Fri, 3 Jul 2015 09:15:38 +0800 Subject: [PATCH] ARM64 / SMP: Switch pr_err() to pr_debug() for disabled GICC entry In-Reply-To: <20150702162940.GF1354@e104818-lin.cambridge.arm.com> References: <1435757843-13236-1-git-send-email-hanjun.guo@linaro.org> <20150702162940.GF1354@e104818-lin.cambridge.arm.com> Message-ID: <5595E23A.9040901@huawei.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2015/7/3 0:29, Catalin Marinas wrote: > On Wed, Jul 01, 2015 at 09:37:23PM +0800, Hanjun Guo wrote: >> It is normal that firmware presents GICC entry or entries (processors) >> with disabled flag in ACPI MADT, taking a system of 16 cpus for example, >> ACPI firmware may present 8 enabled first with another 8 cpus disabled >> in MADT, the disabled cpus can be hot-added later. >> >> Firmware may also present more cpus than the hardware actually has, but >> disabled the unused ones, and easily enable it when the hardware has such >> cpus to make the firmware code scalable. >> >> So that's not an error for disabled cpus in MADT, we can switch >> pr_err() to pr_debug() instead. >> >> Signed-off-by: Hanjun Guo >> --- >> arch/arm64/kernel/smp.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c >> index 4b2121b..5caf04a 100644 >> --- a/arch/arm64/kernel/smp.c >> +++ b/arch/arm64/kernel/smp.c >> @@ -402,7 +402,7 @@ acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor) >> } >> >> if (!(processor->flags & ACPI_MADT_ENABLED)) { >> - pr_err("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid); >> + pr_debug("skipping disabled CPU entry with 0x%llx MPIDR\n", hwid); > That's a pretty harmless change. But looking at the use-case, would we > expect the disabled entries to have a valid hwid? I guess such hwid is > not known, especially if we can hot-plug some CPU at a later time. If Good point, usually it's invalid hwid. > that's the case, can we also move this check before the hwid one? Yes, fully agree, thanks for catching this, will update the patch. Thanks Hanjun