Messages in this thread | | | Date | Wed, 6 May 2009 08:45:06 -0700 | From | Greg KH <> | Subject | Re: [PATCH 5/5] usb_debug: EXPERIMENTAL - poll hcd device to force writes |
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On Wed, May 06, 2009 at 04:41:41PM +0100, Alan Cox wrote: > In other words never lie in the write_room method. Try to send data as > early as possible, but don't queue data inefficiently when the port has > plenty left to send. > > The rules for write_room are simple > > If you say you have space for X bytes you can't say you have room > for less bytes unless those bytes have actually been written - no > window shrinking so to speak. > > If your write_room method works properly, and you fix the buffering logic > then the rest will work. Probably we need usb/serial/buffer.c which has a > generic implementation in then that can be used to replace the completely > bogus hacks in most of the drivers.
I agree, this is the correct solution.
thanks,
greg k-h
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