On 5 April 2017 at 13:02, Graeme Gregory graeme.gregory@linaro.org wrote:

On Wed, Apr 05, 2017 at 03:46:18PM +0800, Heyi Guo wrote:

...

Hi folks,

I found some _CID values of devices on ARM platforms may not be correct:

OpenPlatformPkg/Platforms/ARM/VExpress/AcpiTables/Dsdt.asl: Name(_CID, "PL011") OpenPlatformPkg/Platforms/ARM/Juno/AcpiTables/Dsdt.asl: Name(_CID, "PL050_KBD") OpenPlatformPkg/Platforms/ARM/Juno/AcpiTables/Dsdt.asl: Name(_CID, "PL011")

According to ACPI spec, _CID should be something as _HID or PCI ID string.

There are also lots of similar mistakes in Hisilicon platform ASL files. We can start to fix them when the above issue is confirmed.

Thanks and regards,

I did notice those a while ago and when I double checked the spec I did convince myself they are not actually banned by the spec.

I shall have to recheck again as I can't remember the exact details of why I convinced myself they were OK.

I think it was because they were all platform devices that I saw and the spec says

" A string that uses a bus-specific nomenclature. For example, _CID can be used to specify the PCI ID. The format of a PCI ID string is one of the following:"

But it never really defines the "bus-specific nomenclature" for other buses, so they are not specifically banned.

Graeme

Another perspective on this is to think of the _CID (Compatibility Id) as an indication that the peripheral is compatible with a specific device driver. Therefore, the id may not match any "bus-specific nomenclature", but rather some historical accident of detail from the driver install information. (This is not the specification view, but the way it works in practice.) "PL011" is a very clear example of that.

Evan

-----Original Message----- From: Linaro-uefi [mailto:linaro-uefi-bounces@lists.linaro.org] On Behalf Of Heyi Guo Sent: 06 April 2017 00:06 To: graeme.gregory@linaro.org Cc: Linaro UEFI Mailman List Linaro-uefi@lists.linaro.org Subject: Re: [Linaro-uefi] [OpenPlatformPkg/ARM] Incorrect _CID?

Got it. Thanks :)

Gary (Heyi Guo)

在 4/5/2017 10:55 PM, Graeme Gregory 写道:

On 5 April 2017 at 13:02, Graeme Gregory graeme.gregory@linaro.org wrote:

...

On Wed, Apr 05, 2017 at 03:46:18PM +0800, Heyi Guo wrote:

...

Hi folks,

I found some _CID values of devices on ARM platforms may not be correct:

OpenPlatformPkg/Platforms/ARM/VExpress/AcpiTables/Dsdt.asl: Name(_CID, "PL011") OpenPlatformPkg/Platforms/ARM/Juno/AcpiTables/Dsdt.asl: Name(_CID, "PL050_KBD") OpenPlatformPkg/Platforms/ARM/Juno/AcpiTables/Dsdt.asl: Name(_CID, "PL011")

According to ACPI spec, _CID should be something as _HID or PCI ID string.

There are also lots of similar mistakes in Hisilicon platform ASL files. We can start to fix them when the above issue is confirmed.

Thanks and regards,

I did notice those a while ago and when I double checked the spec I did convince myself they are not actually banned by the spec.

I shall have to recheck again as I can't remember the exact details of why I convinced myself they were OK.

I think it was because they were all platform devices that I saw and the spec says

" A string that uses a bus-specific nomenclature. For example, _CID can be used to specify the PCI ID. The format of a PCI ID string is one of the following:"

But it never really defines the "bus-specific nomenclature" for other buses, so they are not specifically banned.

Graeme

_______________________________________________ Linaro-uefi mailing list Linaro-uefi@lists.linaro.org https://lists.linaro.org/mailman/listinfo/linaro-uefi IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.