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From: Oliver Neukum <oneukum@suse.com>
To: penguin-kernel@i-love.sakura.ne.jp, bjorn@mork.no,
	linux-usb@vger.kernel.org
Cc: Oliver Neukum <oneukum@suse.com>
Subject: [RFC 3/7] CDC-WDM: remove use of intf->dev after potential disconnect
Date: Tue, 22 Sep 2020 13:21:22 +0200	[thread overview]
Message-ID: <20200922112126.16919-4-oneukum@suse.com> (raw)
In-Reply-To: <20200922112126.16919-1-oneukum@suse.com>

After a disconnect intf->dev is not a valid pointer any longer.
As flush() uses it only for logging purposes logging is not
worth it. Remove the dev_err()

Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/class/cdc-wdm.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index b3a3f249a915..1ca2c85a977d 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -603,16 +603,17 @@ static int wdm_flush(struct file *file, fl_owner_t id)
 			test_bit(WDM_DISCONNECTING, &desc->flags),
 			WDM_FLUSH_TIMEOUT);
 
-	/* cannot dereference desc->intf if WDM_DISCONNECTING */
+	/*
+	 * to report the correct error.
+	 * This is best effort
+	 * We are inevitably racing with the hardware.
+	 */
 	if (test_bit(WDM_DISCONNECTING, &desc->flags))
 		return -ENODEV;
 	if (!rv)
 		return -EIO;
 
 	rv = desc->werr;
-	if (rv < 0)
-		dev_err(&desc->intf->dev, "Error in flush path: %d\n",
-			rv);
 
 	return usb_translate_errors(rv);
 }
-- 
2.16.4


  parent reply	other threads:[~2020-09-22 11:21 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-22 11:21 [RFC] fixes for hangs and error reporting in CDC_WDM Oliver Neukum
2020-09-22 11:21 ` [RFC 1/7] CDC-WDM: fix hangs in flush() in multithreaded cases Oliver Neukum
2020-09-22 11:21 ` [RFC 2/7] CDC-WDM: introduce a timeout in flush() Oliver Neukum
2020-09-22 11:21 ` Oliver Neukum [this message]
2020-09-22 11:21 ` [RFC 4/7] CDC-WDM: fix race reporting errors in flush Oliver Neukum
2020-09-22 11:21 ` [RFC 5/7] CDC-WDM: correct error reporting in write() Oliver Neukum
2020-09-22 11:21 ` [RFC 6/7] CDC-WDM: implement fsync Oliver Neukum
2020-09-22 11:21 ` [RFC 7/7] CDC-WDM: making flush() interruptible Oliver Neukum
2020-09-22 11:38   ` Tetsuo Handa
2020-09-22 11:49     ` Oliver Neukum
2020-09-25 15:11 ` [RFC] fixes for hangs and error reporting in CDC_WDM Greg KH
2020-09-25 15:20   ` Tetsuo Handa
2020-09-25 15:28     ` Greg KH
2020-09-25 15:34       ` Tetsuo Handa
2020-09-26  5:40         ` Greg KH
2020-09-29  8:46           ` Oliver Neukum
2020-09-29 10:17             ` Tetsuo Handa

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