Re: [PATCH] pl2303, visor: Match I330 phone more precisely

[Johan Hovold <johan@kernel.org>]

On Wed, Apr 22, 2015 at 12:14:05PM +0200, Jason A. Donenfeld wrote:
> Samsung has just released a portable USB3 SSD, coming in a very small
> and nice form factor. It's USB ID is 04e8:8001, which unfortunately is
> already used by the pl2303 USB serial driver and the Palm Visor driver
> for the Samsung I330 phone cradle. Having pl2303 or visor pick up this
> device ID results in conflicts with the usb-storage driver, which
> handles the newly released portable USB3 SSD.

First of all, the device should not be claimed by both pl2303 and visor.
This predates the git, but it looks like the device id should simply be
removed from pl2303. Care to do that as a preparatory patch?

> To work around this conflict, I've dug up a mailing list post [1] from a
> long time ago, in which a user posts the full USB descriptor
> information. The most specific value in this appears to be the interface
> class, which has value 255 (0xff). Since usb-storage requires an
> interface class of 0x8, I believe it's correct to disambiguate the two
> devices by matching on 0xff inside pl2303 and visor.
> 
> [1] http://permalink.gmane.org/gmane.linux.usb.user/4264

That seems like the way to go. As Sergei already suggested you can use
the interface class 0xff directly in the USB_DEVICE_INTERFACE_CLASS
macro.

Thanks,
Johan