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From: Greg KH on 11 Aug 2010 20:10
2.6.35-stable review patch. If anyone has any objections, please let us know.

------------------

From: Alan Stern <stern(a)rowland.harvard.edu>

commit ae68a83bdc1971cb02fefc7a686ba6d077065e71 upstream.

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(a)rowland.harvard.edu>
CC: Sarah Sharp <sarah.a.sharp(a)linux.intel.com>
CC: David Brownell <david-b(a)pacbell.net>
Acked-by: Sarah Sharp <sarah.a.sharp(a)linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de>

---
drivers/usb/host/ehci-pci.c | 1 +
drivers/usb/host/ehci-sched.c | 10 ++++------
drivers/usb/host/ehci.h | 1 +
3 files changed, 6 insertions(+), 6 deletions(-)

--- a/drivers/usb/host/ehci-pci.c
+++ b/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");
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -1400,7 +1400,6 @@ 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);
@@ -1427,15 +1426,14 @@ 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;
--- a/drivers/usb/host/ehci.h
+++ b/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)


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Prev: [26/67] ide-cd: Do not access completed requests in the irq handler
Next: [097/111] ext4: Fix optional-arg mount options