archive mirror
 help / color / mirror / Atom feed
From: Jeaho Hwang <>
Cc: "Linux team" <>,
	"변무광(Byeon Moo Kwang)/자동화연)Automation Platform연구팀"
Subject: Chipidea USB device goes infinite loop due to interrupt while hw_ep_prime
Date: Mon, 2 Aug 2021 17:38:07 +0900	[thread overview]
Message-ID: <> (raw)


We found an infinite loop inside the function hw_ep_set_halt
(drivers/usb/chipidea/udc.c) if a cablle is repeatedly
connnected/disconnected while ping through RNDIS with chipidea USB

Using ftrace tracing, we found that hw_ep_set_halt is called due to
error return of hw_ep_prime(drivers/usb/chipidea/udc.c:202) which is
called from isr_tr_complete_handler -> isr_setup_status_phase ->

The comment of function hw_ep_prime says (execute without
interruption) but timer interrupt is occurred while hw_ep_prime is
executing. We believe that the interrupt causes an error return of
hw_ep_prime. We tried to protect hw_ep_prime from irqs and then no
case of the infinite loop is occurred.

I want ask if it is appropriate way that turning off irq inside
(threaded) irq handlers. And should we explicitly turn off irqs before
calling hw_ep_prime?


황재호, Jay Hwang, linux team manager of RTst

             reply	other threads:[~2021-08-02  8:38 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-02  8:38 Jeaho Hwang [this message]
     [not found] <>
2021-08-04  1:32 ` Chipidea USB device goes infinite loop due to interrupt while hw_ep_prime Peter Chen
2021-08-04  2:03   ` Jeaho Hwang
2021-08-09  1:27     ` Peter Chen
2021-08-09  1:45       ` Jeaho Hwang
2021-08-09  6:31         ` Peter Chen
2021-08-04  3:11   ` Jeaho Hwang
2021-08-09  1:40     ` Peter Chen

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:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \

* 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).