Re: [PATCH 3/7] usb-storage: Don't bind to uas devices if the uas driver is enabled

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

On 10/24/2013 06:32 PM, Alan Stern wrote:
On Thu, 24 Oct 2013, Hans de Goede wrote:

uas devices have 2 alternative settings on their usb-storage interface,
one for usb-storage and one for uas. Using the uas driver is preferred, so if
the uas driver is enabled, and the device has an uas alt setting, don't bind.

We need a mechanism for the user to force a device into usb-storage
mode, even if the device claims to support UAS.  It would not be at all
surprising to find some devices whose UAS support is broken.

Agreed, this is one of the reasons why I want to share the uas-detect code
between the uas and usb-storage drivers, so that we can have a single
place for a blacklist.

So I think the best way to provide such a user override would be a kernel
module option. But that needs to belong to a single module, so I see 2 options;
1) Turn uas-detect into a separate module
2) Use the existing unusual_dev stuff for this and make uas depend on usb-storage
to get the unusual_dev (included user added extra quirks) from usb-storage

2. Makes the most sense to me, since usb-storage will get loaded anyways when
uas is loaded as they both match on the same usb class.

If you agree that 2. is probably best then I can do an addon patch adding support
for a NO_UAS quirk which will cause the uas-detect code to bail with an error if
present.

Regards,

Hans
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux