From: Richard Genoud <richard.genoud@gmail.com>
To: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Ivo van Doorn <IvDoorn@gmail.com>,
Gertjan van Wingerde <gwingerde@gmail.com>,
Helmut Schaa <helmut.schaa@googlemail.com>,
"John W. Linville" <linville@tuxdriver.com>,
linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] rt2x00: Endless loop on hub port power down
Date: Fri, 04 Apr 2014 11:58:26 +0200 [thread overview]
Message-ID: <533E8242.8080203@gmail.com> (raw)
In-Reply-To: <20140404080453.GA1448@redhat.com>
On 04/04/2014 10:04, Stanislaw Gruszka wrote:
> On Thu, Apr 03, 2014 at 04:48:56PM +0200, Richard Genoud wrote:
>> I've met an endless (or at least very long) loop if I power down the usb
>> port on witch a usb wifi key is plugged.
>> (Ok, it's not very smart to power down a usb port when a usb key is in
>> used... but still, I think that should not lead to an endless loop).
>>
>> I have a lot of:
>> ieee80211 phy1: rt2x00usb_vendor_request: Error - Vendor Request 0x07 failed for offset 0x0438 with error -71
>>
>> (-71==-EPROTO)
>>
>> How to reproduce:
>> - plug an usb wifi key
>> - ip link set wlan0 up
>> - hub-ctrl -b usb_bus -d usb_device -P usb_port -p 0
>>
>> hub-ctrl source: https://github.com/codazoda/hub-ctrl.c/blob/master/hub-ctrl.c
>>
>> The following patch prevents the endless loop, but I'm really not sure
>> that The Right Way To Do It (R)
>
> If device disappear, we should get -ENODEV status, why we get -EPROTO ?
I trace it down, and the EPROTO status comes from ctx.status (returned from usb_start_wait_urb() in drivers/usb/core/message.c)
And, in my case, the ctx.status is set to EPROTO in qtd_copy_status() ( drivers/usb/host/ehci-q.c )
in the code:
} else if (token & QTD_STS_XACT) {
/* timeout, bad CRC, wrong PID, etc */
ehci_dbg(ehci, "devpath %s ep%d%s 3strikes\n",
urb->dev->devpath,
usb_pipeendpoint(urb->pipe),
usb_pipein(urb->pipe) ? "in" : "out");
status = -EPROTO;
enabling this log, I get:
atmel-ehci 700000.ehci: devpath 2.1 ep1in 3strikes
atmel-ehci 700000.ehci: devpath 2.1 ep0in 3strikes
atmel-ehci 700000.ehci: devpath 2.1 ep1in 3strikes
atmel-ehci 700000.ehci: devpath 2.1 ep0in 3strikes
ieee80211 phy0: rt2800usb_tx_sta_fifo_read_completed: Warning - TX status read failed -71
next prev parent reply other threads:[~2014-04-04 9:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-03 14:48 [PATCH] rt2x00: Endless loop on hub port power down Richard Genoud
2014-04-04 8:04 ` Stanislaw Gruszka
2014-04-04 9:58 ` Richard Genoud [this message]
2014-04-04 14:13 ` Stanislaw Gruszka
2014-04-04 15:38 ` Richard Genoud
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