Messages in this thread | | | Date | Tue, 21 May 2002 22:06:40 -0700 | From | Greg KH <> | Subject | Re: What to do with all of the USB UHCI drivers in the kernel ? |
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On Tue, May 21, 2002 at 06:04:21PM -0700, Maksim (Max) Krasnyanskiy wrote: > > >IMO, I think testing with usb-uhci.c and uhci.c is still useful, but > >testing with the -hcd variants is the most ideal since that will be the > >final code base. > > Ok. Here is feedback on 2.5.17 uhci-hcd and usb-uhci-hcd. > I did not notice any difference in behavior. Both have the same > performance, just like 2.4.19-pre8. > > One-shot interrupt transfers are broken in *-hcd drivers. core/hcd.c > returns EINVAL if urb->interval==0. > My Broadcom FW loader (uses usbdevfs) needs one-shot interrupts. So in > order to test Broadcom devices > I changed to hcd.c to allow urb->interval==0. With that change uhci-hcd > works just fine, I can load fw and > use the device. But usb-uhci-hcd kills the machine pretty hard (hw reset > needed). > > Here is a patch for hcd.c.
Thanks for the patch.
> On a side note. Why are URBs still not SLABified ? > Drivers still have those silly urb pools and stuff. I thought you guys were > gonna fix that.
It hasn't been proven that it's really needed. 95% of the current drivers create their urbs when the device is plugged in, and then free them when they are removed. Making that kind of allocation into a slab is a bit silly :)
Now if more drivers start doing fun stuff like the visor.c driver does in the 2.5 tree, then it might make more sense to create a URB specific slab.
thanks,
greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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