Linux-remoteproc Archive on lore.kernel.org
 help / color / Atom feed
From: Sibi Sankar <sibis@codeaurora.org>
To: Evan Green <evgreen@chromium.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>,
	Andy Gross <agross@kernel.org>,
	linux-arm-msm <linux-arm-msm@vger.kernel.org>,
	linux-remoteproc@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	Ohad Ben Cohen <ohad@wizery.com>,
	rohitkr@codeaurora.org, stable@vger.kernel.org,
	linux-kernel-owner@vger.kernel.org
Subject: Re: [PATCH 1/2] remoteproc: qcom: q6v5: Update running state before requesting stop
Date: Fri, 05 Jun 2020 00:20:02 +0530
Message-ID: <ebc56ab0bd61f5b33be976a6643880db@codeaurora.org> (raw)
In-Reply-To: <CAE=gft4v1iHAPJS13fLBXgjt8ZRhD7q894zF_7JvK9QbiTbwhA@mail.gmail.com>

On 2020-06-04 04:03, Evan Green wrote:
> On Tue, Jun 2, 2020 at 10:29 PM Sibi Sankar <sibis@codeaurora.org> 
> wrote:
>> 
>> Evan,
>> Thanks for taking time to review
>> the series.
>> 
>> On 2020-06-02 23:14, Evan Green wrote:
>> > On Tue, Jun 2, 2020 at 9:33 AM Sibi Sankar <sibis@codeaurora.org>
>> > wrote:
>> >>
>> >> Sometimes the stop triggers a watchdog rather than a stop-ack. Update
>> >> the running state to false on requesting stop to skip the watchdog
>> >> instead.
>> >>
>> >> Error Logs:
>> >> $ echo stop > /sys/class/remoteproc/remoteproc0/state
>> >> ipa 1e40000.ipa: received modem stopping event
>> >> remoteproc-modem: watchdog received: sys_m_smsm_mpss.c:291:APPS force
>> >> stop
>> >> qcom-q6v5-mss 4080000.remoteproc-modem: port failed halt
>> >> ipa 1e40000.ipa: received modem offline event
>> >> remoteproc0: stopped remote processor 4080000.remoteproc-modem
>> >>
>> >> Fixes: 3b415c8fb263 ("remoteproc: q6v5: Extract common resource
>> >> handling")
>> >> Cc: stable@vger.kernel.org
>> >> Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
>> >> ---
>> >
>> > Are you sure you want to tolerate this behavior from MSS? This is a
>> > graceful shutdown, modem shouldn't have a problem completing the
>> > proper handshake. If they do, isn't that a bug on the modem side?
>> 
>> The graceful shutdown is achieved
>> though sysmon (enabled using
>> CONFIG_QCOM_SYSMON). When sysmon is
>> enabled we get a shutdown-ack when we
>> try to stop the modem, post which
>> request stop is a basically a nop.
>> Request stop is done to force stop
>> the modem during failure cases (like
>> rmtfs is not running and so on) and
>> we do want to mask the wdog that we get
>> during this scenario ( The locking
>> already prevents the servicing of the
>> wdog during shutdown, the check just
>> prevents the scheduling of crash handler
>> and err messages associated with it).
>> Also this check was always present and
>> was missed during common q6v5 resource
>> helper migration, hence the unused
>> running state in mss driver.
> 
> So you're saying that the intention of the ->running check already in
> q6v5_wdog_interrupt() was to allow either the stop-ack or wdog
> interrupt to complete the stop. This patch just fixes a regression
> introduced during the refactor.
> This patch seems ok to me then. It still sort of seems like a bug that
> the modem responds arbitrarily in one of two ways, even to a "harsh"
> shutdown request.
> 
> I wasn't aware of QCOM_SYSMON. Reading it now, It seems like kind of a

TL;DR
Sysmon when enabled adds a lookup
for qmi service 43 (Subsystem
control service). When we shutdown
the modem, we send a SSCTL_SHUTDOWN_REQ
to the service and the modem responds
with a shutdown-ack interrupt. If you
have rmtfs running with -v turned on
you can notice pending efs transactions
being completed followed by a bye I guess.

> lot... do I really need all this? Can I get by with just remoteproc
> stops?
> Anyway, for this patch:
> 
> Reviewed-by: Evan Green <evgreen@chromium.org>

Thanks for the review!

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project.

  reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-02 16:32 Sibi Sankar
2020-06-02 16:32 ` [PATCH 2/2] remoteproc: qcom_q6v5_mss: Remove redundant running state Sibi Sankar
2020-06-02 17:39   ` Evan Green
2020-07-28  6:20   ` Bjorn Andersson
2020-06-02 17:44 ` [PATCH 1/2] remoteproc: qcom: q6v5: Update running state before requesting stop Evan Green
2020-06-03  5:29   ` Sibi Sankar
2020-06-03 22:33     ` Evan Green
2020-06-04 18:50       ` Sibi Sankar [this message]
2020-07-28  6:19       ` Bjorn Andersson

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=ebc56ab0bd61f5b33be976a6643880db@codeaurora.org \
    --to=sibis@codeaurora.org \
    --cc=agross@kernel.org \
    --cc=bjorn.andersson@linaro.org \
    --cc=evgreen@chromium.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-kernel-owner@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-remoteproc@vger.kernel.org \
    --cc=ohad@wizery.com \
    --cc=rohitkr@codeaurora.org \
    --cc=stable@vger.kernel.org \
    /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

Linux-remoteproc Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-remoteproc/0 linux-remoteproc/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-remoteproc linux-remoteproc/ https://lore.kernel.org/linux-remoteproc \
		linux-remoteproc@vger.kernel.org
	public-inbox-index linux-remoteproc

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-remoteproc


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git