On Tue, 12 Mar 2013, Jenya Y wrote:
> > I'll try to work out a patch in the next few days. Can you recreate
> > the arrangement where all the errors occurred, in order to test the
> > patch when it is ready?
> >
> > Alan Stern
> >
> Absolutely, I'd be glad to help.
>
> Just tell me what kernel should I use to apply your patch and I'll
> prepare the env to test it.
Here is a patch for you to test. It should apply to any of the 3.8.y
kernels.
Alan Stern
Index: 3.8/drivers/usb/core/hcd-pci.c
===================================================================
--- 3.8.orig/drivers/usb/core/hcd-pci.c
+++ 3.8/drivers/usb/core/hcd-pci.c
@@ -37,24 +37,23 @@
/* PCI-based HCs are common, but plenty of non-PCI HCs are used too */
-#ifdef CONFIG_PM_SLEEP
-
-/* Coordinate handoffs between EHCI and companion controllers
- * during system resume
+/*
+ * Coordinate handoffs between EHCI and companion controllers
+ * during EHCI probing and system resume.
*/
-static DEFINE_MUTEX(companions_mutex);
+static DECLARE_RWSEM(companions_rwsem);
#define CL_UHCI PCI_CLASS_SERIAL_USB_UHCI
#define CL_OHCI PCI_CLASS_SERIAL_USB_OHCI
#define CL_EHCI PCI_CLASS_SERIAL_USB_EHCI
-enum companion_action {
- SET_HS_COMPANION, CLEAR_HS_COMPANION, WAIT_FOR_COMPANIONS
-};
+typedef void (*companion_fn)(struct pci_dev *pdev, struct usb_hcd *hcd,
+ struct pci_dev *companion, struct usb_hcd *companion_hcd);
-static void companion_common(struct pci_dev *pdev, struct usb_hcd *hcd,
- enum companion_action action)
+/* Iterate over PCI devices in the same slot as pdev and call fn for each */
+static void for_each_companion(struct pci_dev *pdev, struct usb_hcd *hcd,
+ companion_fn fn)
{
struct pci_dev *companion;
struct usb_hcd *companion_hcd;
@@ -69,87 +68,87 @@ static void companion_common(struct pci_
if (companion->bus != pdev->bus ||
PCI_SLOT(companion->devfn) != slot)
continue;
-
companion_hcd = pci_get_drvdata(companion);
if (!companion_hcd)
continue;
-
- /* For SET_HS_COMPANION, store a pointer to the EHCI bus in
- * the OHCI/UHCI companion bus structure.
- * For CLEAR_HS_COMPANION, clear the pointer to the EHCI bus
- * in the OHCI/UHCI companion bus structure.
- * For WAIT_FOR_COMPANIONS, wait until the OHCI/UHCI
- * companion controllers have fully resumed.
- */
-
- if ((pdev->class == CL_OHCI || pdev->class == CL_UHCI) &&
- companion->class == CL_EHCI) {
- /* action must be SET_HS_COMPANION */
- dev_dbg(&companion->dev, "HS companion for %s\n",
- dev_name(&pdev->dev));
- hcd->self.hs_companion = &companion_hcd->self;
-
- } else if (pdev->class == CL_EHCI &&
- (companion->class == CL_OHCI ||
- companion->class == CL_UHCI)) {
- switch (action) {
- case SET_HS_COMPANION:
- dev_dbg(&pdev->dev, "HS companion for %s\n",
- dev_name(&companion->dev));
- companion_hcd->self.hs_companion = &hcd->self;
- break;
- case CLEAR_HS_COMPANION:
- companion_hcd->self.hs_companion = NULL;
- break;
- case WAIT_FOR_COMPANIONS:
- device_pm_wait_for_dev(&pdev->dev,
- &companion->dev);
- break;
- }
- }
+ fn(pdev, hcd, companion, companion_hcd);
}
}
-static void set_hs_companion(struct pci_dev *pdev, struct usb_hcd *hcd)
+/*
+ * We're about to add an EHCI controller, which will unceremoniously grab
+ * all the port connections away from its companions. To prevent annoying
+ * error messages, lock the companion's root hub and gracefully unconfigure
+ * it beforehand. Leave it locked until the EHCI controller is all set.
+ */
+void ehci_pre_add(struct pci_dev *pdev, struct usb_hcd *hcd,
+ struct pci_dev *companion, struct usb_hcd *companion_hcd)
{
- mutex_lock(&companions_mutex);
- dev_set_drvdata(&pdev->dev, hcd);
- companion_common(pdev, hcd, SET_HS_COMPANION);
- mutex_unlock(&companions_mutex);
+ struct usb_device *udev;
+
+ if (companion->class == CL_OHCI || companion->class == CL_UHCI) {
+ udev = companion_hcd->self.root_hub;
+ usb_lock_device(udev);
+ usb_set_configuration(udev, 0);
+ }
}
-static void clear_hs_companion(struct pci_dev *pdev, struct usb_hcd *hcd)
+/*
+ * Adding the EHCI controller has either succeeded or failed. Set the
+ * companion pointer accordingly, and in either case, reconfigure and
+ * unlock the root hub.
+ */
+void ehci_post_add(struct pci_dev *pdev, struct usb_hcd *hcd,
+ struct pci_dev *companion, struct usb_hcd *companion_hcd)
{
- mutex_lock(&companions_mutex);
- dev_set_drvdata(&pdev->dev, NULL);
+ struct usb_device *udev;
- /* If pdev is OHCI or UHCI, just clear its hs_companion pointer */
- if (pdev->class == CL_OHCI || pdev->class == CL_UHCI)
- hcd->self.hs_companion = NULL;
+ if (companion->class == CL_OHCI || companion->class == CL_UHCI) {
+ if (dev_get_drvdata(&pdev->dev)) { /* Succeeded */
+ dev_dbg(&pdev->dev, "HS companion for %s\n",
+ dev_name(&companion->dev));
+ companion_hcd->self.hs_companion = &hcd->self;
+ }
+ udev = companion_hcd->self.root_hub;
+ usb_set_configuration(udev, 1);
+ usb_unlock_device(udev);
+ }
+}
- /* Otherwise search for companion buses and clear their pointers */
- else
- companion_common(pdev, hcd, CLEAR_HS_COMPANION);
- mutex_unlock(&companions_mutex);
+/*
+ * We just added a non-EHCI controller. Find the EHCI controller to
+ * which it is a companion, and store a pointer to the bus structure.
+ */
+void non_ehci_add(struct pci_dev *pdev, struct usb_hcd *hcd,
+ struct pci_dev *companion, struct usb_hcd *companion_hcd)
+{
+ if (pdev->class == CL_OHCI || pdev->class == CL_UHCI) {
+ if (companion->class == CL_EHCI) {
+ dev_dbg(&pdev->dev, "FS/LS companion for %s\n",
+ dev_name(&companion->dev));
+ hcd->self.hs_companion = &companion_hcd->self;
+ }
+ }
}
-static void wait_for_companions(struct pci_dev *pdev, struct usb_hcd *hcd)
+/* We are removing an EHCI controller. Clear the companions' pointers. */
+void ehci_remove(struct pci_dev *pdev, struct usb_hcd *hcd,
+ struct pci_dev *companion, struct usb_hcd *companion_hcd)
{
- /* Only EHCI controllers need to wait.
- * No locking is needed because a controller cannot be resumed
- * while one of its companions is getting unbound.
- */
- if (pdev->class == CL_EHCI)
- companion_common(pdev, hcd, WAIT_FOR_COMPANIONS);
+ companion_hcd->self.hs_companion = NULL;
}
-#else /* !CONFIG_PM_SLEEP */
+#if defined(CONFIG_PM_SLEEP) || defined(CONFIG_PM_RUNTIME)
-static inline void set_hs_companion(struct pci_dev *d, struct usb_hcd *h) {}
-static inline void clear_hs_companion(struct pci_dev *d, struct usb_hcd *h) {}
-static inline void wait_for_companions(struct pci_dev *d, struct usb_hcd *h) {}
+/* An EHCI controller must wait for its companions before resuming. */
+void ehci_wait_for_companions(struct pci_dev *pdev, struct usb_hcd *hcd,
+ struct pci_dev *companion, struct usb_hcd *companion_hcd)
+{
+ if (companion->class == CL_OHCI || companion->class == CL_UHCI)
+ device_pm_wait_for_dev(&pdev->dev, &companion->dev);
+}
-#endif /* !CONFIG_PM_SLEEP */
+#endif /* SLEEP || RUNTIME */
/*-------------------------------------------------------------------------*/
@@ -212,7 +211,7 @@ int usb_hcd_pci_probe(struct pci_dev *de
driver->description)) {
dev_dbg(&dev->dev, "controller already in use\n");
retval = -EBUSY;
- goto clear_companion;
+ goto put_hcd;
}
hcd->regs = ioremap_nocache(hcd->rsrc_start, hcd->rsrc_len);
if (hcd->regs == NULL) {
@@ -239,16 +238,35 @@ int usb_hcd_pci_probe(struct pci_dev *de
if (region == PCI_ROM_RESOURCE) {
dev_dbg(&dev->dev, "no i/o regions available\n");
retval = -EBUSY;
- goto clear_companion;
+ goto put_hcd;
}
}
pci_set_master(dev);
- retval = usb_add_hcd(hcd, dev->irq, IRQF_SHARED);
+ /* Note: dev_set_drvdata must be called while holding the rwsem */
+ if (dev->class == CL_EHCI) {
+ down_write(&companions_rwsem);
+ dev_set_drvdata(&dev->dev, hcd);
+ for_each_companion(dev, hcd, ehci_pre_add);
+ retval = usb_add_hcd(hcd, dev->irq, IRQF_SHARED);
+ if (retval != 0)
+ dev_set_drvdata(&dev->dev, NULL);
+ for_each_companion(dev, hcd, ehci_post_add);
+ up_write(&companions_rwsem);
+ } else {
+ down_read(&companions_rwsem);
+ dev_set_drvdata(&dev->dev, hcd);
+ retval = usb_add_hcd(hcd, dev->irq, IRQF_SHARED);
+ if (retval != 0)
+ dev_set_drvdata(&dev->dev, NULL);
+ else
+ for_each_companion(dev, hcd, non_ehci_add);
+ up_read(&companions_rwsem);
+ }
+
if (retval != 0)
goto unmap_registers;
- set_hs_companion(dev, hcd);
if (pci_dev_run_wake(dev))
pm_runtime_put_noidle(&dev->dev);
@@ -261,8 +279,7 @@ release_mem_region:
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
} else
release_region(hcd->rsrc_start, hcd->rsrc_len);
-clear_companion:
- clear_hs_companion(dev, hcd);
+put_hcd:
usb_put_hcd(hcd);
disable_pci:
pci_disable_device(dev);
@@ -305,14 +322,29 @@ void usb_hcd_pci_remove(struct pci_dev *
usb_hcd_irq(0, hcd);
local_irq_enable();
- usb_remove_hcd(hcd);
+ /* Note: dev_set_drvdata must be called while holding the rwsem */
+ if (dev->class == CL_EHCI) {
+ down_write(&companions_rwsem);
+ for_each_companion(dev, hcd, ehci_remove);
+ usb_remove_hcd(hcd);
+ dev_set_drvdata(&dev->dev, NULL);
+ up_write(&companions_rwsem);
+ } else {
+ /* Not EHCI; just clear the companion pointer */
+ down_read(&companions_rwsem);
+ hcd->self.hs_companion = NULL;
+ usb_remove_hcd(hcd);
+ dev_set_drvdata(&dev->dev, NULL);
+ up_read(&companions_rwsem);
+ }
+
if (hcd->driver->flags & HCD_MEMORY) {
iounmap(hcd->regs);
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
} else {
release_region(hcd->rsrc_start, hcd->rsrc_len);
}
- clear_hs_companion(dev, hcd);
+
usb_put_hcd(hcd);
pci_disable_device(dev);
}
@@ -458,8 +490,15 @@ static int resume_common(struct device *
pci_set_master(pci_dev);
if (hcd->driver->pci_resume && !HCD_DEAD(hcd)) {
- if (event != PM_EVENT_AUTO_RESUME)
- wait_for_companions(pci_dev, hcd);
+
+ /*
+ * Only EHCI controllers have to wait for their companions.
+ * No locking is needed because PCI controller drivers do not
+ * get unbound during system resume.
+ */
+ if (pci_dev->class == CL_EHCI && event != PM_EVENT_AUTO_RESUME)
+ for_each_companion(pci_dev, hcd,
+ ehci_wait_for_companions);
retval = hcd->driver->pci_resume(hcd,
event == PM_EVENT_RESTORE);
--
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