Re: [RFC v2 3/5] PCIe, Add runtime PM support to PCIe port

[huang ying]

On Sat, May 5, 2012 at 4:55 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> On Friday, May 04, 2012, Bjorn Helgaas wrote:
>> On Fri, May 4, 2012 at 2:13 AM, Huang Ying <ying.huang@xxxxxxxxx> wrote:
>> > From: Zheng Yan <zheng.z.yan@xxxxxxxxx>
>> >
>> > This patch adds runtime PM support to PCIe port. ÂThis is needed by
>> > PCIe D3cold support, where PCIe device in slot may be powered on/off
>> > by PCIe port.
>>
>> I assume this works for integrated PCIe devices as well as those that
>> are plugged into a slot and can be physically removed -- maybe the
>> text "in slot" is superfluous?
>>
>> > Because runtime suspend is broken for some chipset, a white list is
>> > used to enable runtime PM support for only chipset known to work.
>>
>> A whitelist requires perpetual maintenance. ÂEvery time a new working
>> chipset comes out, you have to update the whitelist. ÂThat doesn't
>> seem right.
>
> Well, we can't possibly enable the feature for all PCIe ports in existence
> either, because some of them will not work with it (almost surely).

What do you think about the idea from Bjorn to use some kind of blacklist here?

Best Regards,
Huang Ying
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