# HG changeset patch
# User Stephan Diestelhorst <stephan.diestelhorst@amd.com>
# Date 1259187617 -3600
# Node ID d483a02fbc5eda5907dd1467368f9becc2014b6b
# Parent  0ec8f040b20aaa3044aa14f3a7fbc8dbb7854836
EHCI Lock-up: Backport of patch by Oliver Neukum <oliver@neukum.org>.
	This patch attempts to work around a chipset issue found on Intel
	chipsets found in MSI Wind netbooks.

diff -r 0ec8f040b20a -r d483a02fbc5e drivers/usb/host/ehci-hcd.c
--- a/drivers/usb/host/ehci-hcd.c	Sun Nov 15 12:36:02 2009 +0100
+++ b/drivers/usb/host/ehci-hcd.c	Wed Nov 25 23:20:17 2009 +0100
@@ -28,6 +28,7 @@
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/timer.h>
+#include <linux/ktime.h>
 #include <linux/list.h>
 #include <linux/interrupt.h>
 #include <linux/reboot.h>
@@ -655,6 +656,7 @@
 	ehci_readl(ehci, &ehci->regs->command);	/* unblock posted writes */
 	msleep(5);
 	up_write(&ehci_cf_port_reset_rwsem);
+	ehci->last_periodic_enable = ktime_get_real();
 
 	temp = HC_VERSION(ehci_readl(ehci, &ehci->caps->hc_capbase));
 	ehci_info (ehci,
diff -r 0ec8f040b20a -r d483a02fbc5e drivers/usb/host/ehci-pci.c
--- a/drivers/usb/host/ehci-pci.c	Sun Nov 15 12:36:02 2009 +0100
+++ b/drivers/usb/host/ehci-pci.c	Wed Nov 25 23:20:17 2009 +0100
@@ -129,6 +129,12 @@
 		return retval;
 
 	switch (pdev->vendor) {
+	case PCI_VENDOR_ID_INTEL:
+		if (pdev->device == 0x27cc) {
+			ehci->broken_periodic = 1;
+			ehci_info(ehci, "using broken periodic workaround\n");
+		}
+		break;
 	case PCI_VENDOR_ID_TDI:
 		if (pdev->device == PCI_DEVICE_ID_TDI_EHCI) {
 			hcd->has_tt = 1;
diff -r 0ec8f040b20a -r d483a02fbc5e drivers/usb/host/ehci-sched.c
--- a/drivers/usb/host/ehci-sched.c	Sun Nov 15 12:36:02 2009 +0100
+++ b/drivers/usb/host/ehci-sched.c	Wed Nov 25 23:20:17 2009 +0100
@@ -456,6 +456,8 @@
 	/* make sure ehci_work scans these */
 	ehci->next_uframe = ehci_readl(ehci, &ehci->regs->frame_index)
 		% (ehci->periodic_size << 3);
+	if (unlikely(ehci->broken_periodic))
+		ehci->last_periodic_enable = ktime_get_real();
 	return 0;
 }
 
@@ -467,6 +469,15 @@
 	if (--ehci->periodic_sched)
 		return 0;
 
+	if (unlikely(ehci->broken_periodic)) {
+		ktime_t safe = ktime_add_us(ehci->last_periodic_enable, 1000);
+		ktime_t now = ktime_get_real();
+		s64 delay = ktime_us_delta(safe, now);
+		
+		if (unlikely(delay > 0))
+			udelay(delay);
+	}
+
 	/* did setting PSE not take effect yet?
 	 * takes effect only at frame boundaries...
 	 */
diff -r 0ec8f040b20a -r d483a02fbc5e drivers/usb/host/ehci.h
--- a/drivers/usb/host/ehci.h	Sun Nov 15 12:36:02 2009 +0100
+++ b/drivers/usb/host/ehci.h	Wed Nov 25 23:20:17 2009 +0100
@@ -118,6 +118,7 @@
 	unsigned		stamp;
 	unsigned		random_frame;
 	unsigned long		next_statechange;
+	ktime_t			last_periodic_enable;
 	u32			command;
 
 	/* SILICON QUIRKS */
@@ -126,6 +127,7 @@
 	unsigned		big_endian_mmio:1;
 	unsigned		big_endian_desc:1;
 	unsigned		has_amcc_usb23:1;
+	unsigned		broken_periodic:1;
 
 	/* required for usb32 quirk */
 	#define OHCI_CTRL_HCFS          (3 << 6)