Re: [PATCH 05/23] USB: set the correct interval for interrupt URBs

On Fri,  9 Mar 2007 20:04:26 -0800, Greg Kroah-Hartman <[email protected]> wrote:

> From: Alan Stern <[email protected]>
> 
> This patch (as862) fixes a couple of bugs in the way usbcore handles
> intervals for interrupt URBs.  usb_interrupt_msg (and usb_bulk_msg for
> backward compatibility) don't set the interval correctly for
> high-speed devices.  proc_do_submiturb() doesn't set it correctly when
> a bulk URB is submitted to an interrupt endpoint.
> 
> Signed-off-by: Alan Stern <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>

Woops, looks like I missed this. Konrad Rzeszutek of IBM alerted me to
this fix.

This looks good:

> --- a/drivers/usb/core/devio.c
> @@ -1053,7 +1048,11 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
>  	as->urb->setup_packet = (unsigned char*)dr;
>  	as->urb->start_frame = uurb->start_frame;
>  	as->urb->number_of_packets = uurb->number_of_packets;
> -	as->urb->interval = interval;
> +	if (uurb->type == USBDEVFS_URB_TYPE_ISO ||
> +			ps->dev->speed == USB_SPEED_HIGH)
> +		as->urb->interval = 1 << min(15, ep->desc.bInterval - 1);
> +	else
> +		as->urb->interval = ep->desc.bInterval;
>          as->urb->context = as;

... because it's how we should calculate the interval, and we assign
the field in URB, so fine. But this looks bogus:

> +++ b/drivers/usb/core/message.c
> @@ -221,10 +221,15 @@ int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
>  
>  	if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
>  			USB_ENDPOINT_XFER_INT) {
> +		int interval;
> +
> +		if (usb_dev->speed == USB_SPEED_HIGH)
> +			interval = 1 << min(15, ep->desc.bInterval - 1);
> +		else
> +			interval = ep->desc.bInterval;
>  		pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
>  		usb_fill_int_urb(urb, usb_dev, pipe, data, len,
> -				usb_api_blocking_completion, NULL,
> -				ep->desc.bInterval);
> +				usb_api_blocking_completion, NULL, interval);

This is because usb_fill_int_urb does this computation already.

Looks like someone (Jeff Layton maybe?) forwarded you a patch for RHEL 4,
which is based on 2.6.9, and so it needs the last segment.

Alan, am I right?

-- Pete

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