On Mon, Jun 27, 2016 at 2:32 PM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> 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 > > <pprakash@xxxxxxxxxxxxxx> wrote: > > > > > > > > > On 6/9/2016 4:43 PM, Hoan Tran wrote: > > >> Hi Prashanth, > > >> > > >> On Thu, Jun 9, 2016 at 3:25 PM, Prakash, Prashanth > > >> <pprakash@xxxxxxxxxxxxxx> 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 <hotran@xxxxxxx> wrote: > > >>>>> Hi Prashanth, > > >>>>> > > >>>>> > > >>>>> On Wed, Jun 8, 2016 at 5:32 PM, Prakash, Prashanth > > >>>>> <pprakash@xxxxxxxxxxxxxx> wrote: > > >>>>>> On 6/8/2016 10:24 AM, Hoan Tran wrote: > > >>>>>>> Hi Ashwin, > > >>>>>>> > > >>>>>>> On Wed, Jun 8, 2016 at 5:18 AM, Ashwin Chaugule > > >>>>>>> <ashwin.chaugule@xxxxxxxxxx> wrote: > > >>>>>>>> + Prashanth (Can you please have a look as well?) > > >>>>>>>> > > >>>>>>>> On 31 May 2016 at 15:35, Hoan Tran <hotran@xxxxxxx> 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 <pprakash@xxxxxxxxxxxxxx> > > > > 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? Thanks Hoan -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
