From: Marc Zyngier <maz@kernel.org>
To: Maulik Shah <mkshah@codeaurora.org>
Cc: Stephen Boyd <swboyd@chromium.org>,
bjorn.andersson@linaro.org, evgreen@chromium.org,
mka@chromium.org, linux-kernel@vger.kernel.org,
linux-arm-msm@vger.kernel.org, agross@kernel.org,
linus.walleij@linaro.org, tglx@linutronix.de,
dianders@chromium.org, rnayak@codeaurora.org,
ilina@codeaurora.org, lsrao@codeaurora.org,
linux-kernel-owner@vger.kernel.org,
mkshah=codeaurora.org@mg.codeaurora.org
Subject: Re: [RFC 1/2] irqchip: qcom: pdc: Introduce irq_set_wake call
Date: Thu, 12 Mar 2020 11:38:50 +0000 [thread overview]
Message-ID: <68130578959b36d92b721131a9b35e94@kernel.org> (raw)
In-Reply-To: <6fd12e17-5216-d136-b454-2ee7e4a1686e@codeaurora.org>
On 2020-03-12 11:33, Maulik Shah wrote:
> On 2/27/2020 6:39 AM, Marc Zyngier wrote:
>> Maulik,
>>
>> I'd appreciate if you could Cc me on all irqchip patches.
>
> Sure Marc, i kept you in Cc for V2 addressing stephen's comments.
Thanks. Make sure you use maz@kernel.org (I accidentally replied from
my personal address).
>
>>
>> On 2020-02-25 17:16, Stephen Boyd wrote:
>>> Quoting Maulik Shah (2020-02-21 03:20:59)
>>>>
>>>> On 2/20/2020 7:51 AM, Stephen Boyd wrote:
>>>>
>>>> How are wakeups supposed to work when the CPU cluster power is
>>>> disabled
>>>> in low power CPU idle modes? Presumably the parent irq
>>>> controller is
>>>> powered off (in this case it's an ARM GIC) and we would need to
>>>> have the
>>>> interrupt be "enabled" or "unmasked" at the PDC for the irq to
>>>> wakeup
>>>> the cluster.
>>>>
>>>> Correct. Interrupt needs to be "enabled" or "unmasked" at wakeup
>>>> capable PDC
>>>> for irqchip to wakeup from "deep" low power modes where parent GIC
>>>> may not be
>>>> monitoring interrupt and only PDC is monitoring.
>>>> these "deep" low power modes can either be triggered by kernel
>>>> "suspend" or
>>>> "cpuidle" path for which drivers may or may not have registered for
>>>> suspend or
>>>> cpu/cluster pm notifications to make a decision of enabling wakeup
>>>> capability.
>>
>> Loosing interrupt delivery in idle is not an acceptable behaviour.
>> Idle != suspend.
>
> Agree, we are not lossing it, but rather RFC v1 was keeping a
> requirement on drivers to keep wake
> enabled by calling irq_set_wake when the interrupt is routed via PDC,
> even after coming out of suspend.
An endpoint driver shouldn't have to know what interrupt controller it
is connected to. So your "when the interrupt is routed via PDC" is
not enforceable.
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2020-03-12 11:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-17 13:00 [RFC 0/2] pdc: Introduce irq_set_wake call Maulik Shah
2020-02-17 13:00 ` [RFC 1/2] irqchip: qcom: " Maulik Shah
2020-02-20 2:21 ` Stephen Boyd
[not found] ` <4c80783d-8ad0-9bd8-c42e-01659fa81afe@codeaurora.org>
2020-02-25 17:16 ` Stephen Boyd
2020-02-27 1:09 ` Marc Zyngier
2020-03-12 11:33 ` Maulik Shah
2020-03-12 11:38 ` Marc Zyngier [this message]
2020-02-17 13:00 ` [RFC 2/2] pinctrl: qcom: Remove forwarding irq_disable and irq_enable call to parent Maulik Shah
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=68130578959b36d92b721131a9b35e94@kernel.org \
--to=maz@kernel.org \
--cc=agross@kernel.org \
--cc=bjorn.andersson@linaro.org \
--cc=dianders@chromium.org \
--cc=evgreen@chromium.org \
--cc=ilina@codeaurora.org \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel-owner@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lsrao@codeaurora.org \
--cc=mka@chromium.org \
--cc=mkshah=codeaurora.org@mg.codeaurora.org \
--cc=mkshah@codeaurora.org \
--cc=rnayak@codeaurora.org \
--cc=swboyd@chromium.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).