On Tue, 13 Aug 2013, Oleksij Rempel wrote:

> If usb auto suspend is enabled or system run in to suspend/resume
> cycle ath9k-htc adapter will stop to response. It is reproducible on xhci HCs.
> 
> Host part of problem:
> XHCI do timing calculation based on Transfer Type and bInterval,
> immediately after device was detected. Ath9k-htc try to overwrite
> this parameters on module probe and some changes in FW,
> since we do not initiate usb reset from the driver this changes
> are not took to account. So, before any kind of suspend or reset,
> host controller will operate with old parameters. Only after suspend/resume
> and if interface id stay unchanged, new parameters will by applied. Host
> will send bulk data with no intervals (?), which will cause
> overflow on FIFO of EP4.
> 
> Firmware part of problem:
> By default, ath9k-htc adapters configured with EP3 and EP4
> as interrupt endpoints. Current firmware will try to overwrite
> ConfigDescriptor to make EP3 and EP4 bulk. FIFO for this endpoints
> stay not reconfigured, so under the hood it is still Int EP.

One little comment on the patch title.  You aren't converting the 
endpoints back from bulk to interrupt; rather you are preventing the 
driver and firmware from trying to convert them from interrupt to bulk.

Alan Stern

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