From: Sebastian Andrzej Siewior Date: Wed, 11 Jan 2012 11:42:32 +0000 (+0100) Subject: usb/uas: only bind if the hcd supports SG X-Git-Tag: v3.4-rc1~184^2~22^2~121^2~16^2~3 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c898add51c7b5b99fcecdeaf4df2ca30949cacb6;p=pandora-kernel.git usb/uas: only bind if the hcd supports SG The UAS driver requires SG support by the HCD operating the device. This patch stops UAS from operating on a HCD without sg support and prints a message to let him know. The spec says: |For [USB2] backward compatibility, the device shall present [BOT] as |alternate interface zero (primary) and [UAS] as alternate interface one |(secondary). A device which does not need backward compatibility with |[BOT] shall present [UAS] as alternate interface zero. In [USB2] |systems, the [BOT] driver or an associated filter driver may need to |issue a SET INTERFACE request for alternate interface one and then allow |the [UAS] driver to load. If the user used usb_modeswitch to switch to UAS then he can go back to BOT or use a different HCD. In case UAS is the only interface then there is currently no way out. In future usb_sg_wait() should be extended to provide a non-blocking interface so it can work with the UAS driver. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Sarah Sharp --- Reading git-diff-tree failed