All of lore.kernel.org
 help / color / mirror / Atom feed
From: Oliver Neukum <oneukum@suse.com>
To: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org,
	jonas.karlsson@actia.se
Cc: Oliver Neukum <oneukum@suse.com>
Subject: [PATCH 1/2] cdc-acm: close race betrween suspend() and acm_softint
Date: Wed, 15 Apr 2020 17:13:57 +0200	[thread overview]
Message-ID: <20200415151358.32664-1-oneukum@suse.com> (raw)

Suspend increments a counter, then kills the URBs,
then kills the scheduled work. The scheduled work, however,
may reschedule the URBs. Fix this by having the work
check the counter.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Tested-by: Jonas Karlsson <jonas.karlsson@actia.se>
---
 drivers/usb/class/cdc-acm.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 84d6f7df09a4..4ef68e6671aa 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -557,14 +557,14 @@ static void acm_softint(struct work_struct *work)
 	struct acm *acm = container_of(work, struct acm, work);
 
 	if (test_bit(EVENT_RX_STALL, &acm->flags)) {
-		if (!(usb_autopm_get_interface(acm->data))) {
+		smp_mb(); /* against acm_suspend() */
+		if (!acm->susp_count) {
 			for (i = 0; i < acm->rx_buflimit; i++)
 				usb_kill_urb(acm->read_urbs[i]);
 			usb_clear_halt(acm->dev, acm->in);
 			acm_submit_read_urbs(acm, GFP_KERNEL);
-			usb_autopm_put_interface(acm->data);
+			clear_bit(EVENT_RX_STALL, &acm->flags);
 		}
-		clear_bit(EVENT_RX_STALL, &acm->flags);
 	}
 
 	if (test_and_clear_bit(EVENT_TTY_WAKEUP, &acm->flags))
-- 
2.16.4


             reply	other threads:[~2020-04-15 15:14 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-15 15:13 Oliver Neukum [this message]
2020-04-15 15:13 ` [PATCH 2/2] cdc-acm: introduce a cool down Oliver Neukum

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=20200415151358.32664-1-oneukum@suse.com \
    --to=oneukum@suse.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jonas.karlsson@actia.se \
    --cc=linux-usb@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
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.