On Wed, Jul 14, 2010 at 11:03:23AM -0400, Alan Stern wrote:
> This patch (as1405) fixes a small bug in ehci-hcd's isochronous
> scheduler. Not all EHCI controllers are PCI, and the code shouldn't
> assume that they are. Instead, introduce a special flag for
> controllers which need to delay iso scheduling for full-speed devices
> beyond the scheduling threshold.
>
> Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> CC: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Acked-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
> CC: David Brownell <david-b@xxxxxxxxxxx>
> CC: stable@xxxxxxxxxx
>
> ---
>
> Index: usb-2.6/drivers/usb/host/ehci.h
> ===================================================================
> --- usb-2.6.orig/drivers/usb/host/ehci.h
> +++ usb-2.6/drivers/usb/host/ehci.h
> @@ -130,6 +130,7 @@ struct ehci_hcd { /* one per controlle
> unsigned has_amcc_usb23:1;
> unsigned need_io_watchdog:1;
> unsigned broken_periodic:1;
> + unsigned fs_i_thresh:1; /* Intel iso scheduling */
>
> /* required for usb32 quirk */
> #define OHCI_CTRL_HCFS (3 << 6)
> Index: usb-2.6/drivers/usb/host/ehci-pci.c
> ===================================================================
> --- usb-2.6.orig/drivers/usb/host/ehci-pci.c
> +++ usb-2.6/drivers/usb/host/ehci-pci.c
> @@ -114,6 +114,7 @@ static int ehci_pci_setup(struct usb_hcd
> break;
> case PCI_VENDOR_ID_INTEL:
> ehci->need_io_watchdog = 0;
> + ehci->fs_i_thresh = 1;
> if (pdev->device == 0x27cc) {
> ehci->broken_periodic = 1;
> ehci_info(ehci, "using broken periodic workaround\n");
> Index: usb-2.6/drivers/usb/host/ehci-sched.c
> ===================================================================
> --- usb-2.6.orig/drivers/usb/host/ehci-sched.c
> +++ usb-2.6/drivers/usb/host/ehci-sched.c
> @@ -1399,7 +1399,6 @@ iso_stream_schedule (
> int status;
> unsigned mod = ehci->periodic_size << 3;
> struct ehci_iso_sched *sched = urb->hcpriv;
> - struct pci_dev *pdev;
>
> if (sched->span > (mod - SCHEDULE_SLOP)) {
> ehci_dbg (ehci, "iso request %p too long\n", urb);
> @@ -1426,15 +1425,14 @@ iso_stream_schedule (
> * slot in the schedule, implicitly assuming URB_ISO_ASAP.
> */
> if (likely (!list_empty (&stream->td_list))) {
> - pdev = to_pci_dev(ehci_to_hcd(ehci)->self.controller);
> start = stream->next_uframe;
>
> /* For high speed devices, allow scheduling within the
> - * isochronous scheduling threshold. For full speed devices,
> - * don't. (Work around for Intel ICH9 bug.)
> + * isochronous scheduling threshold. For full speed devices
> + * and Intel PCI-based controllers, don't (work around for
> + * Intel ICH9 bug).
> */
> - if (!stream->highspeed &&
> - pdev->vendor == PCI_VENDOR_ID_INTEL)
> + if (!stream->highspeed && ehci->fs_i_thresh)
> next = now + ehci->i_thresh;
> else
> next = now;
>
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