Re: [RFT] rtl8187: use DMA-aware buffers with usb_control_msg

Greg KH
2009-05-09T16:39:21Z

On Sat, May 09, 2009 at 11:50:14AM -0400, John W. Linville wrote:
> > usb_control messages are slow and should not be on the "fast path" of
> > any data being sent through the device. Any overhead of the
> > kmalloc/kfree is totally eaten up by the actual transmission turn around
> > time of the message itself, so you don't have to worry about the
> > performance impact.
>
> Yeah, I don't like the original version either. Even if the kmalloc's
> aren't a big performance hit, the failure path sucks. I've included a
> new version below, but unfortunately I haven't had a chance to test it.
> Please give it a try if you get a chance?

Looks good to me, a bit cleaner even.

thanks,

greg k-h