Re: Strange problem with USB device

From: Ibrahim Erturk <ierturk@ieee.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Larry Finger <Larry.Finger@lwfinger.net>,
	linux-usb@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	linux-pci@vger.kernel.org
Subject: Re: Strange problem with USB device
Date: Fri, 11 Jun 2021 03:08:16 +0300	[thread overview]
Message-ID: <CAFHYy-iMty-jjZzgzRA6tOezN-RJ+o4hRL1kZk+tuN1i-K9Ukg@mail.gmail.com> (raw)
In-Reply-To: <20210609021237.GA1826754@rowland.harvard.edu>

Hi,

I've already attached logs and a snapshot from the device manager on
the windows side into the bug report. Hope this helps.

Regards,
Ibrahim ERTURK

On Wed, Jun 9, 2021 at 5:12 AM Alan Stern <stern@rowland.harvard.edu> wrote:
>
> On Tue, Jun 08, 2021 at 03:56:11PM -0500, Larry Finger wrote:
> > On 6/8/21 1:53 PM, Alan Stern wrote:
> > > I don't get it.  If this is a PCIe device, why should it appear
> > > on a USB bus?  Wouldn't you expect it to show up as a PCI device
> > > on a PCI bus instead?
> > >
> >
> > I do not know the internal details, but Realtek packages a PCIe wifi
> > device and a bluetooth USB device in the same package. Intel does the
> > same thing on my Wireless 7260.
> >
> > My lsusb shows:
> > Bus 003 Device 002: ID 8087:8000 Intel Corp. Integrated Rate Matching Hub
> > Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
> > Bus 001 Device 002: ID 8087:8008 Intel Corp. Integrated Rate Matching Hub
> > Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
> > Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
> > Bus 002 Device 004: ID 8087:07dc Intel Corp. Bluetooth wireless interface
> > Bus 002 Device 003: ID 0bda:c822 Realtek Semiconductor Corp. Bluetooth Radio
> > Bus 002 Device 002: ID 04f2:b3b2 Chicony Electronics Co., Ltd TOSHIBA
> > Web Camera - FHD
> > Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
> >
> > I have no devices plugged into a USB port.
>
> Okay, now I get the picture.  The Intel PCIe card contains an
> EHCI USB host controller plus a couple of on-board USB Bluetooth
> devices and an on-board USB webcam, in addition to the PCIe wifi
> device.
>
> Which means you're looking at the problem all wrong.  It isn't a
> USB problem at all; it's a PCI problem.  Namely, why doesn't the
> system detect the USB host controller on the PCIe board?
>
> I have added the PCI maintainer and mailing list to the CC.
> Maybe they can help shed some light.
>
> The original Suse Bugzilla report:
>
>         https://bugzilla.suse.com/show_bug.cgi?id=1186889
>
> shows the Realtek board at PCI address 0000:03:00.0, but there's
> no mention of a USB host controller on that board.  The only host
> controller on the system is the one at address 0000:00:14.0,
> which is xHCI and is directly on the motherboard.
>
> Furthermore, there's no trace of any mention of an EHCI USB host
> controller in the system log.  So maybe the board has to be told
> somehow to turn that controller on before it will show up, and
> the rtw_8822ce driver isn't giving the appropriate order.
>
> Can the bug reporter get information from Windows about the USB
> host controllers, and in particular, the one on the RTL8822
> board?
>
> Alan Stern