[PATCH V7 5/7] ACPI: Delay the enumeration on the devices whose dependency has not met

zhichang.yuan yuanzhichang at hisilicon.com
Wed Mar 15 19:21:58 PDT 2017

Hi, Rafael,

Thanks for your review!

On 2017/3/14 5:24, Rafael J. Wysocki wrote:
> On Monday, March 13, 2017 10:42:41 AM zhichang.yuan wrote:
>> In commit 40e7fcb1929(ACPI: Add _DEP support to fix battery issue on Asus
>> T100TA), the '_DEP' was supported to solve the dependency of Asus battery. But
>> this patch is specific to Asus battery device.
>> In the real world, there are other devices which need the dependency to play the
>> role on the enumeration order. For example, all the Hip06 LPC
>> periperals(IPMI-BT, uart, etc) must be scanned after the LPC host driver
>> finished the probing. So, it makes sense to add a checking whether the ACPI
>> device meet all the dependencies during its enumeration slot, if not, the
>> enumeration will be delayed till all dependency master finish their work.
>> This patch adds the dependency checking in ACPI enumeration, also the
>> corresponding handling to retrigger the Hip06 LPC peripherals' scanning.
> AFAICS, _DEP is generally abused in the wild and cannot be made generic.  Sorry.

>From the ACPI specification, _DEP is for operation region accesses.
You are right...

How about we add a ACPI handler for our LPC bus?? Just like amba.
In this way, we also can solve the issue about LPC enumeration order.


> Thanks,
> Rafael
> .

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