linux-kernel - Re: [PATCH 12/13] mailbox: pcc: Add support for PCCT extended PCC subspaces(type 3/4)

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Message-ID: <20210715113102.oww24dj73fq2imbl@bogus>
Date:   Thu, 15 Jul 2021 12:31:02 +0100
From:   Sudeep Holla <sudeep.holla@....com>
To:     Cristian Marussi <cristian.marussi@....com>
Cc:     linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org,
        "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Sudeep Holla <sudeep.holla@....com>,
        Jassi Brar <jassisinghbrar@...il.com>
Subject: Re: [PATCH 12/13] mailbox: pcc: Add support for PCCT extended PCC
 subspaces(type 3/4)

On Wed, Jul 14, 2021 at 07:52:16PM +0100, Cristian Marussi wrote:
> On Thu, Jul 08, 2021 at 07:08:50PM +0100, Sudeep Holla wrote:
> > With all the plumbing in place to avoid accessing PCCT type and other
> > fields directly from the PCCT table all the time, let us now add the
> > support for extended PCC subspaces(type 3 and 4).
> >
> > Signed-off-by: Sudeep Holla <sudeep.holla@....com>
> > ---
>
> Hi Sudeep,
>
> just a few general observation on Type 3/4 subspaces from the spec
> Table 14.7:
>
> - "If a slave-subspace is present in the PCCT, then the platform interrupt flag must be set to 1." table 14.7
>
>   Maybe is worth to WARN on this if this assumption is violated by the
>   ACPI table we found.
>
> - "Note that if interrupts are edge triggered, then each subspace must have its own unique interrupt."
>
>   Same here, maybe it's worth also to check this, so that after all the
>   pchan->db_irq has been obtained no edge triggered irqs are duplicated
>   before requesting them.
>

Both valid points and in my TODO list, just forgot to address this as I
didn't have a setup to check/flag these up. I will address them in next
version.

Thanks for reviewing these patches.

--
Regards,
Sudeep