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From: "Bollinger, Seth" <Seth.Bollinger@digi.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg KH <gregkh@linuxfoundation.org>,
	USB list <linux-usb@vger.kernel.org>,
	Seth Bollinger <seth.boll@gmail.com>
Subject: Re: USB reset problem
Date: Thu, 6 Jun 2019 15:19:14 +0000	[thread overview]
Message-ID: <3D970B56-C8AE-4635-BE92-4FC6F7F8AF9D@digi.com> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1906061101180.1641-100000@iolanthe.rowland.org>

> On Jun 6, 2019, at 10:03 AM, Alan Stern <stern@rowland.harvard.edu> wrote:
> 
> EPERM means that the file descriptor was not opened with write access.  
> It has nothing to do with reset failures.

Yes, I was confused by that as well so spent some time instrumenting the kernel.  It definitely is open for writing, and get’s by the initial f_mode check in devio.c:usbdev_do_ioctl.

Is it possibly a default error that’s returned when some deeper error is encountered?  Unfortunately I was unable to determine exactly where it was coming from...

Seth


  reply	other threads:[~2019-06-06 15:19 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-06 13:55 USB reset problem Bollinger, Seth
2019-06-06 14:36 ` Greg KH
2019-06-06 14:51   ` Bollinger, Seth
2019-06-06 15:03     ` Alan Stern
2019-06-06 15:19       ` Bollinger, Seth [this message]
2019-06-06 15:29         ` Greg KH
2019-06-06 14:37 ` Alan Stern
2019-06-06 15:01   ` Bollinger, Seth

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