On Tue, Aug 16, 2016 at 4:56 AM, Rafael J. Wysocki [off-list ref] wrote:

On Monday, August 15, 2016 04:41:22 PM Hoan Tran wrote:

quoted

Hi Rafael,

On Mon, Aug 15, 2016 at 4:18 PM, Rafael J. Wysocki [off-list ref] wrote:

quoted

On Monday, August 15, 2016 09:45:24 AM Hoan Tran wrote:

quoted

On Mon, Jun 27, 2016 at 2:32 PM, Rafael J. Wysocki [off-list ref] wrote:

quoted

On Monday, June 27, 2016 11:27:42 AM Hoan Tran wrote:

quoted

Hi Jassi and Rafael,

On Wed, Jun 15, 2016 at 9:19 AM, Prakash, Prashanth
[off-list ref] wrote:

quoted

On 6/9/2016 4:43 PM, Hoan Tran wrote:

quoted

Hi Prashanth,

On Thu, Jun 9, 2016 at 3:25 PM, Prakash, Prashanth
[off-list ref] wrote:

quoted

On 6/9/2016 2:47 PM, Hoan Tran wrote:

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Hi Ashwin and Prashanth,

On Wed, Jun 8, 2016 at 5:41 PM, Hoan Tran [off-list ref] wrote:

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Hi Prashanth,


On Wed, Jun 8, 2016 at 5:32 PM, Prakash, Prashanth
[off-list ref] wrote:

quoted

On 6/8/2016 10:24 AM, Hoan Tran wrote:

quoted

Hi Ashwin,

On Wed, Jun 8, 2016 at 5:18 AM, Ashwin Chaugule
[off-list ref] wrote:

quoted

+ Prashanth (Can you please have a look as well?)

On 31 May 2016 at 15:35, Hoan Tran [off-list ref] wrote:

quoted

Hi Ashwin,

Hi,

Sorry about the delay. I'm in the middle of switching jobs and
locations, so its been a bit crazy lately.

It's ok and hope you're doing well.

quoted

I dont have any major
concerns with this code, although there could be subtle issues with
this IRQ thing. In this patchset, your intent is to add support for
PCC subspace type 2. But you're also adding support for tx command
completion which is not specific to Type 2. We could support that even
in Type 1. Hence I wanted to separate the two, not just for review,
but also the async IRQ completion has subtle issues esp. in the case
of async platform notification, where you could have a PCC client in
the OS writing to the cmd bit and the platform sending an async
notification by writing to some bits in the same 8byte address as the
cmd bit. So we need some mutual exclusivity there, otherwise the OS
and platform could step on each other. Perhaps Prashanth has better
insight into this.

I think, this mutual exclusivity could be in another patch.

Ashwin,
Sorry, I am not sure how we can prevent platform and OSPM from stepping on
each other.  There is a line is spec that says "all operations on status field
must be made using interlocked operations", but not sure what these
interlocked operation translates to.

Yes, I had the same question about how to prevent it.

For platform notification, if the hardware doesn't support interlocked
operations. I think we can use a workaround that, platform triggers
interrupt to OSPM without touching status field. The OSPM PCC client
will decide what to do with this interrupt. For example, OSPM sends a
consumer command to check it.

How do we decide which platform can support this interlocked operation?
and how do we decide between a completion notification and platform
notification?

Truly, we should follow the specification. But I don't know if there's
any hardware support this interlocked operation.
For the decide between a completion notification and platform notification
 - Completion notification: Bit "Command Complete" is set.
 - Platform notification: Bit "Command Complete" is not set.

quoted

I think the ACPI spec on platform notification is quite ambiguous and it is
best to get the necessary clarification and/or correction before implementing
anything related to platform notification.

Agreed, a clarification inside ACPI Specification is needed

This patch look good to me, as it doesn't deal with platform notification.
We can try to get some clarification from spec side before handling the platform
notification pieces.

Reviewed-by: Prashanth Prakash <redacted>

Do you have plan to apply this patch ?

Yes.

Thanks,
Rafael

Hi Rafael,

This patch had an ACK from Prashanth.  Can you consider to merge
this patch please?

Can you please resend it with the ACK?

Correcting, it got a "Reviewed-by: Prashanth Prakash
[off-list ref]". Is it OK?

Yes, it is.

Already resend.

Thanks
Hoan

Thanks,
Rafael