Re: [PATCH 1/1] HID: usbhid: add usb_clear_halt determination for next hid_start_in

On Mon, 25 Aug 2014, vichy wrote:

hi Oliver:

2014-08-25 18:21 GMT+08:00 Oliver Neukum [off-list ref]:

quoted

On Fri, 2014-08-22 at 14:23 -0400, Alan Stern wrote:

quoted

On Sat, 23 Aug 2014, vichy wrote:

quoted

from your patch, I have some questions:
a. in Alan's version, if both HID_CLEAR_HALT and HID_RESET_PENDING are
set, hid_reset will both "clear ep halt" and "reset devcie".
But in original one, even HID_CLEAR_HALT and HID_RESET_PENDING are
both set, hid_reset only do one of them.

Yes.  In my patch, the clear-halt handler will turn on the
HID_RESET_PENDING bit if something goes wrong.  In that case we want to
do both things.

Why? If we reset, why bother clearing a halt? Especially as this
may mean waiting the full 5 seconds for a timeout.

I think what Alan mean is IF CLEAR HALT fail, we reset the device.
That is what below "In that case" mean.
 "In that case we want to do both things."

Exactly.  Suppose initially HID_CLEAR_HALT is set and HID_RESET_PENDING 
is off.  If the usb_clear_halt call fails, we want to recover by 
performing a reset.

Alan Stern

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