On 01/09/2012 04:51 PM, Matthew Wilcox wrote:
On Mon, Jan 09, 2012 at 07:45:46AM -0800, Greg KH wrote:
UAS is not using this function. It comes with usb_sg_wait() which
queues the URBs _and_ waits until the transfer is complete. For UAS
it should be non-blocking because we need to do this from IRQ
context.
So the question is how to deal with it.
Fix the UAS driver to not do a blocking call from interrupt context?
It's not in interrupt context. The SCSI layer expects you to queue
the command and return; usg_sg_wait queues the command and waits for it
to finish. UAS can't use that.
No. This is only _if_ we support streams which is only true on 3.0
which is handled by xhci which does support sg. No problem here.
All other controller are 2.0 only and enqueue sgs in completion of the
status URB.
Sebastian
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