On Monday, August 15, 2016 04:41:22 PM Hoan Tran wrote: > Hi Rafael, > > On Mon, Aug 15, 2016 at 4:18 PM, Rafael J. Wysocki <[email protected]> wrote: > > On Monday, August 15, 2016 09:45:24 AM Hoan Tran wrote: > >> On Mon, Jun 27, 2016 at 2:32 PM, Rafael J. Wysocki <[email protected]> > >> wrote: > >> > > >> > On Monday, June 27, 2016 11:27:42 AM Hoan Tran wrote: > >> > > Hi Jassi and Rafael, > >> > > > >> > > On Wed, Jun 15, 2016 at 9:19 AM, Prakash, Prashanth > >> > > <[email protected]> wrote: > >> > > > > >> > > > > >> > > > On 6/9/2016 4:43 PM, Hoan Tran wrote: > >> > > >> Hi Prashanth, > >> > > >> > >> > > >> On Thu, Jun 9, 2016 at 3:25 PM, Prakash, Prashanth > >> > > >> <[email protected]> wrote: > >> > > >>> > >> > > >>> On 6/9/2016 2:47 PM, Hoan Tran wrote: > >> > > >>>> Hi Ashwin and Prashanth, > >> > > >>>> > >> > > >>>> On Wed, Jun 8, 2016 at 5:41 PM, Hoan Tran <[email protected]> wrote: > >> > > >>>>> Hi Prashanth, > >> > > >>>>> > >> > > >>>>> > >> > > >>>>> On Wed, Jun 8, 2016 at 5:32 PM, Prakash, Prashanth > >> > > >>>>> <[email protected]> wrote: > >> > > >>>>>> On 6/8/2016 10:24 AM, Hoan Tran wrote: > >> > > >>>>>>> Hi Ashwin, > >> > > >>>>>>> > >> > > >>>>>>> On Wed, Jun 8, 2016 at 5:18 AM, Ashwin Chaugule > >> > > >>>>>>> <[email protected]> wrote: > >> > > >>>>>>>> + Prashanth (Can you please have a look as well?) > >> > > >>>>>>>> > >> > > >>>>>>>> On 31 May 2016 at 15:35, Hoan Tran <[email protected]> wrote: > >> > > >>>>>>>>> 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. > >> > > >>>>>>> > >> > > >>>>>>>> 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. > >> > > >> > >> > > >>> 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 <[email protected]> > >> > > > >> > > 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 > <[email protected]>". Is it OK?
Yes, it is. Thanks, Rafael
