Messages in this thread | | | Date | Wed, 17 Dec 2014 13:44:03 +0800 | From | Jiang Liu <> | Subject | Re: [patch 4/4] acpi: ioapic: Respect the resource flags |
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Hi Thomas, Should I keep the development history or start from scratch for this ACPI resource patch set? Thanks! Gerry
On 2014/12/12 19:43, Thomas Gleixner wrote: > On Fri, 12 Dec 2014, Jiang Liu wrote: >> On 2014/12/12 15:53, Thomas Gleixner wrote: >>> On Thu, 11 Dec 2014, Yinghai Lu wrote: >>>> On Thu, Dec 11, 2014 at 11:48 AM, Thomas Gleixner <tglx@linutronix.de> wrote: >>>>> +static inline bool is_valid_mem_resource(struct resource *res) >>>>> +{ >>>>> + return !(res->flags & IORESOURCE_DISABLED) && >>>>> + (res->flags & IORESOURCE_MEM); >>>>> +} >>>>> + >>>> There is minor problem about mem pref handling, original code will ignore them. >>> >>> Bah. I missed that in that well documented function... >>> >>>> with this patch will let it follow through. >>>> >>>> should change is_valid_mem_resource to is_valid_mem_nonpref_resource()... >>>> >>>> +static inline bool is_valid_mem_nonpref_resource(struct resource *res) >>>> { >>>> return !(res->flags & IORESOURCE_DISABLED) && >>>> - (res->flags & IORESOURCE_MEM); >>>> + (res->flags & IORESOURCE_MEM) && >>>> + !(res->flags & IORESOURCE_PREFETCH); >>>> } >>> >>> Unfortunately that does not help, because nothing sets the >>> IORESOURCE_PREFETCH flag. Will fix it proper. >>> >>> I still have no explanation why the translation offset needs to be >>> applied here. >> Hi Thomas, >> I have read related section in ACPI spec, seems the addition >> of translation_offset is redundant here. >> >> Quotation from ACPI spec 5a, 6.4.3.5.1 >> For bridges that translate addresses across the bridge, this is the >> offset that must be added to the address on the secondary side to >> obtain the address on the primary side. Non-bridge devices must list >> 0 for all Address Translation offset bits. >> >> Quotation from ACPI spec 5, 9.17 I/O APIC Device: >> It must also contain a _CRS object that reports the base address of the >> I/O APIC device. The _CRS object is required to contain only one >> resource, a memory resource pointing to the I/O APIC register base. >> >> IO APIC is not a bridge, so translation_offset should always be zero. > > Right and we really need a proper interface for this on the acpi side, > so we can avoid all that dance in the usage sites. > > Thanks, > > tglx > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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