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? Thanks, Rafael
