[PATCH] USB: storage: Ignore driver CD interface of SR9700 USB Ethernet adapters

[PATCH] USB: storage: Ignore driver CD interface of SR9700 USB Ethernet adapters

[Ethan Nelson-Moore]

Some SR9700 devices have an SPI flash chip containing a virtual driver
CD, in which case they appear as a device with two interfaces and
product ID 0x9702. Interface 0 is the driver CD and interface 1 is the
Ethernet device. A separate patch to the sr9700 driver will add
support for these devices.

Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
---
 drivers/usb/storage/unusual_devs.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/usb/storage/unusual_devs.h b/drivers/usb/storage/unusual_devs.h
index 47f50d7a385c..b5a764d1ed50 100644
--- a/drivers/usb/storage/unusual_devs.h
+++ b/drivers/usb/storage/unusual_devs.h
@@ -1719,6 +1719,13 @@ UNUSUAL_DEV(  0x0fce, 0xe092, 0x0000, 0x0000,
 		USB_SC_DEVICE, USB_PR_DEVICE, NULL,
 		US_FL_IGNORE_RESIDUE ),
 
+/* Ignore driver CD interface of SR9700 USB Ethernet adapters */
+UNUSUAL_DEV( 0x0fe6, 0x9702, 0x0000, 0xffff,
+		"CoreChips",
+		"SR9700 USB Ethernet Adapter",
+		USB_SC_DEVICE, USB_PR_DEVICE, NULL,
+		US_FL_IGNORE_DEVICE ),
+
 /*
  * Reported by Kevin Cernekee <kpc-usbdev@gelato.uiuc.edu>
  * Tested on hardware version 1.10.
-- 
2.43.0

Re: [PATCH] USB: storage: Ignore driver CD interface of SR9700 USB Ethernet adapters

[Alan Stern]

On Wed, Dec 10, 2025 at 10:21:44PM -0800, Ethan Nelson-Moore wrote:
> Some SR9700 devices have an SPI flash chip containing a virtual driver
> CD, in which case they appear as a device with two interfaces and
> product ID 0x9702. Interface 0 is the driver CD and interface 1 is the
> Ethernet device. A separate patch to the sr9700 driver will add
> support for these devices.

This just a statement of fact; it doesn't explain anything.  For 
example, it doesn't explain what the patch does, and most importantly, 
it doesn't explain _why_ the patch does it.

In particular, is there any real reason for ignoring the CD interface?  
What's wrong with letting it bind to the usb-storage driver and be 
available to the user as a virtual CD?

Alan Stern

Re: [PATCH] USB: storage: Ignore driver CD interface of SR9700 USB Ethernet adapters

[Ethan Nelson-Moore]

Hi, Alan,

Thanks for your feedback. Sorry for the extremely delayed response.

On Thu, Dec 11, 2025 at 7:06 AM Alan Stern <stern@rowland.harvard.edu> wrote:
> This just a statement of fact; it doesn't explain anything.  For
> example, it doesn't explain what the patch does, and most importantly,
> it doesn't explain _why_ the patch does it.
I will fix this in a new version if you think this patch is worth merging.

> In particular, is there any real reason for ignoring the CD interface?
> What's wrong with letting it bind to the usb-storage driver and be
> available to the user as a virtual CD?
The driver works without this patch, but the CD is still visible, and
it does not contain Linux drivers, so it is just an annoyance.
Is that enough justification for blacklisting it?
Is there any way to have the storage device be ignored only when the
sr9700 driver is loaded? Would that be better?

Ethan

Re: [PATCH] USB: storage: Ignore driver CD interface of SR9700 USB Ethernet adapters

[Alan Stern]

On Thu, Jan 29, 2026 at 10:03:52PM -0800, Ethan Nelson-Moore wrote:
> Hi, Alan,
> 
> Thanks for your feedback. Sorry for the extremely delayed response.
> 
> On Thu, Dec 11, 2025 at 7:06 AM Alan Stern <stern@rowland.harvard.edu> wrote:
> > This just a statement of fact; it doesn't explain anything.  For
> > example, it doesn't explain what the patch does, and most importantly,
> > it doesn't explain _why_ the patch does it.
> I will fix this in a new version if you think this patch is worth merging.
> 
> > In particular, is there any real reason for ignoring the CD interface?
> > What's wrong with letting it bind to the usb-storage driver and be
> > available to the user as a virtual CD?
> The driver works without this patch, but the CD is still visible, and
> it does not contain Linux drivers, so it is just an annoyance.

Except for people who are interested in the drivers it contains, even 
though they aren't meant for Linux.

> Is that enough justification for blacklisting it?

IMO, no.  I don't think kernel modifications and blacklist entries 
should be added merely because of somebody's personal preferences.

> Is there any way to have the storage device be ignored only when the
> sr9700 driver is loaded? Would that be better?

No.

However, you can always create a local module parameter for usb-storage 
in a config file under /etc/modprobe.d, telling it to ignore the device:

	options usb-storage VID:PID:i

where VID and PID and the Vendor and Product IDs of the device and the 
"i" stands for "ignore".

Alan Stern

Re: [PATCH] USB: storage: Ignore driver CD interface of SR9700 USB Ethernet adapters

[Ethan Nelson-Moore]

On Fri, Jan 30, 2026 at 7:45 AM Alan Stern <stern@rowland.harvard.edu> wrote:
> IMO, no.  I don't think kernel modifications and blacklist entries
> should be added merely because of somebody's personal preferences.
Okay. That makes sense to me.

> However, you can always create a local module parameter for usb-storage
> in a config file under /etc/modprobe.d, telling it to ignore the device:
>
>         options usb-storage VID:PID:i
>
> where VID and PID and the Vendor and Product IDs of the device and the
> "i" stands for "ignore".
Thanks. I'll do that.

Ethan