linux-usb.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Yunhao Tian <t123yh.xyz@gmail.com>
Cc: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-usb@vger.kernel.org
Subject: Re: PREEMPT_RT causes scheduling errors with f_rndis USB gadget
Date: Mon, 7 Mar 2022 09:55:11 +0100	[thread overview]
Message-ID: <YiXIb43PR4bayMHw@linutronix.de> (raw)
In-Reply-To: <CAFQXTv2B10=i6DMV1iJpOT-Mj9F93hOi_415cn49N6X_yDFw2g@mail.gmail.com>

On 2022-03-06 18:17:54 [+0800], Yunhao Tian wrote:
> Hi everyone,
Hi,

> I'm using Linux 5.15.24-rt31 kernel with PREEMPT_RT enabled, on my
> RK3308 board. I set up f_rndis gadget with the following script, and
> plugged my board to a x86 Linux computer running 5.15.25 kernel:

Is this 5.15.24-rt31 as-is or are there other patches involved?
What UDC is used here?

…
> [ 25.993834] NOHZ tick-stop error: Non-RCU local softirq work is
> pending, handler #80!!!
that is sched

…
> [ 25.995885] NOHZ tick-stop error: Non-RCU local softirq work is
> pending, handler #180!!!

that is additionally hrtimer.
I did touch hrtimer but I did not yet touch sched so I account myself as
50% innocent.
You don't have by chance change the thread affinity of tasks/ interrupt
threads? The SoC has 4 cores if I see this right.

> If I turn off PREEMPT_RT, there won't be any errors while downloading.
> 
> I believe this problem is not tied to any specific board, and anyone
> can reproduce this problem using a Raspberry Pi (Although I didn't try
> because I don't have one). I would like to ask for assistance
> regarding this problem.

Let me try dummy_udc…

Sebastian

      parent reply	other threads:[~2022-03-07  8:55 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-06 10:17 PREEMPT_RT causes scheduling errors with f_rndis USB gadget Yunhao Tian
2022-03-06 10:35 ` Greg KH
2022-03-06 10:57   ` Yunhao Tian
2022-03-06 12:11     ` Greg KH
2022-03-07  8:55 ` Sebastian Andrzej Siewior [this message]

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=YiXIb43PR4bayMHw@linutronix.de \
    --to=bigeasy@linutronix.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rt-users@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=t123yh.xyz@gmail.com \
    /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).