Messages in this thread | | | Date | Wed, 1 Mar 2006 13:54:23 -0800 | From | Greg KH <> | Subject | Re: MAX_USBFS_BUFFER_SIZE |
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On Wed, Mar 01, 2006 at 10:42:35PM +0100, Ren? Rebe wrote: > Hi, > > On Wednesday 01 March 2006 22:32, Greg KH wrote: > > On Wed, Mar 01, 2006 at 09:16:25PM +0100, Ren?? Rebe wrote: > > > Hi, > > > > > > I wonder if: > > > > > > drivers/usb/core/devio.c:86 > > > #define MAX_USBFS_BUFFER_SIZE 16384 > > > > > > is some random, or outdated limit or if there really is some code path that could > > > not handle bigger URBs. > > > > > > For performance reasons I would like to use bigger packages for an image > > > aquisition device. > > > > Why not just send down 2 urbs with that size then, that would keep the > > pipe quite full. > > Because that requires even more modifications to libusb and sane (i_usb) ...
No, do it in your application I mean.
> So, queing alot URBs is the recommended way to sustain the bus? Allowing > way bigger buffers will not be realistic?
16Kb is "way big" in the USB scheme of things aready. Look at the size of your endpoint. It's probably _very_ small compared to that. So no, larger buffer sizes is not realistic at all.
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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