linux/drivers/usb/core/hcd-pci.c
Alan Stern c548795abe USB: add check to detect host controller hardware removal
This patch (as1391) fixes a problem that can occur when USB host
controller hardware is hot-unplugged.  If no interrupts are generated
by the unplug then the HCD may not realize that the controller is
gone, and the subsequent unbind may hang waiting for interrupts that
never arrive.

The solution (for PCI-based controllers) is to call the HCD's
interrupt handler at the start of usb_hcd_pci_remove().  If the
hardware is gone, the handler will realize this when it tries to read
the controller's status register.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 14:35:33 -07:00

515 lines
13 KiB
C

/*
* (C) Copyright David Brownell 2000-2002
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pm_runtime.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <asm/io.h>
#include <asm/irq.h>
#ifdef CONFIG_PPC_PMAC
#include <asm/machdep.h>
#include <asm/pmac_feature.h>
#include <asm/pci-bridge.h>
#include <asm/prom.h>
#endif
#include "usb.h"
/* 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
*/
static DEFINE_MUTEX(companions_mutex);
#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
};
static void companion_common(struct pci_dev *pdev, struct usb_hcd *hcd,
enum companion_action action)
{
struct pci_dev *companion;
struct usb_hcd *companion_hcd;
unsigned int slot = PCI_SLOT(pdev->devfn);
/* Iterate through other PCI functions in the same slot.
* If pdev is OHCI or UHCI then we are looking for EHCI, and
* vice versa.
*/
companion = NULL;
for (;;) {
companion = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, companion);
if (!companion)
break;
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;
}
}
}
}
static void set_hs_companion(struct pci_dev *pdev, struct usb_hcd *hcd)
{
mutex_lock(&companions_mutex);
dev_set_drvdata(&pdev->dev, hcd);
companion_common(pdev, hcd, SET_HS_COMPANION);
mutex_unlock(&companions_mutex);
}
static void clear_hs_companion(struct pci_dev *pdev, struct usb_hcd *hcd)
{
mutex_lock(&companions_mutex);
dev_set_drvdata(&pdev->dev, NULL);
/* 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;
/* Otherwise search for companion buses and clear their pointers */
else
companion_common(pdev, hcd, CLEAR_HS_COMPANION);
mutex_unlock(&companions_mutex);
}
static void wait_for_companions(struct pci_dev *pdev, struct usb_hcd *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);
}
#else /* !CONFIG_PM_SLEEP */
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) {}
#endif /* !CONFIG_PM_SLEEP */
/*-------------------------------------------------------------------------*/
/* configure so an HC device and id are always provided */
/* always called with process context; sleeping is OK */
/**
* usb_hcd_pci_probe - initialize PCI-based HCDs
* @dev: USB Host Controller being probed
* @id: pci hotplug id connecting controller to HCD framework
* Context: !in_interrupt()
*
* Allocates basic PCI resources for this USB host controller, and
* then invokes the start() method for the HCD associated with it
* through the hotplug entry's driver_data.
*
* Store this function in the HCD's struct pci_driver as probe().
*/
int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
struct hc_driver *driver;
struct usb_hcd *hcd;
int retval;
if (usb_disabled())
return -ENODEV;
if (!id)
return -EINVAL;
driver = (struct hc_driver *)id->driver_data;
if (!driver)
return -EINVAL;
if (pci_enable_device(dev) < 0)
return -ENODEV;
dev->current_state = PCI_D0;
if (!dev->irq) {
dev_err(&dev->dev,
"Found HC with no IRQ. Check BIOS/PCI %s setup!\n",
pci_name(dev));
retval = -ENODEV;
goto err1;
}
hcd = usb_create_hcd(driver, &dev->dev, pci_name(dev));
if (!hcd) {
retval = -ENOMEM;
goto err1;
}
if (driver->flags & HCD_MEMORY) {
/* EHCI, OHCI */
hcd->rsrc_start = pci_resource_start(dev, 0);
hcd->rsrc_len = pci_resource_len(dev, 0);
if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len,
driver->description)) {
dev_dbg(&dev->dev, "controller already in use\n");
retval = -EBUSY;
goto err2;
}
hcd->regs = ioremap_nocache(hcd->rsrc_start, hcd->rsrc_len);
if (hcd->regs == NULL) {
dev_dbg(&dev->dev, "error mapping memory\n");
retval = -EFAULT;
goto err3;
}
} else {
/* UHCI */
int region;
for (region = 0; region < PCI_ROM_RESOURCE; region++) {
if (!(pci_resource_flags(dev, region) &
IORESOURCE_IO))
continue;
hcd->rsrc_start = pci_resource_start(dev, region);
hcd->rsrc_len = pci_resource_len(dev, region);
if (request_region(hcd->rsrc_start, hcd->rsrc_len,
driver->description))
break;
}
if (region == PCI_ROM_RESOURCE) {
dev_dbg(&dev->dev, "no i/o regions available\n");
retval = -EBUSY;
goto err2;
}
}
pci_set_master(dev);
retval = usb_add_hcd(hcd, dev->irq, IRQF_DISABLED | IRQF_SHARED);
if (retval != 0)
goto err4;
set_hs_companion(dev, hcd);
return retval;
err4:
if (driver->flags & HCD_MEMORY) {
iounmap(hcd->regs);
err3:
release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
} else
release_region(hcd->rsrc_start, hcd->rsrc_len);
err2:
clear_hs_companion(dev, hcd);
usb_put_hcd(hcd);
err1:
pci_disable_device(dev);
dev_err(&dev->dev, "init %s fail, %d\n", pci_name(dev), retval);
return retval;
}
EXPORT_SYMBOL_GPL(usb_hcd_pci_probe);
/* may be called without controller electrically present */
/* may be called with controller, bus, and devices active */
/**
* usb_hcd_pci_remove - shutdown processing for PCI-based HCDs
* @dev: USB Host Controller being removed
* Context: !in_interrupt()
*
* Reverses the effect of usb_hcd_pci_probe(), first invoking
* the HCD's stop() method. It is always called from a thread
* context, normally "rmmod", "apmd", or something similar.
*
* Store this function in the HCD's struct pci_driver as remove().
*/
void usb_hcd_pci_remove(struct pci_dev *dev)
{
struct usb_hcd *hcd;
hcd = pci_get_drvdata(dev);
if (!hcd)
return;
/* Fake an interrupt request in order to give the driver a chance
* to test whether the controller hardware has been removed (e.g.,
* cardbus physical eject).
*/
local_irq_disable();
usb_hcd_irq(0, hcd);
local_irq_enable();
usb_remove_hcd(hcd);
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);
}
EXPORT_SYMBOL_GPL(usb_hcd_pci_remove);
/**
* usb_hcd_pci_shutdown - shutdown host controller
* @dev: USB Host Controller being shutdown
*/
void usb_hcd_pci_shutdown(struct pci_dev *dev)
{
struct usb_hcd *hcd;
hcd = pci_get_drvdata(dev);
if (!hcd)
return;
if (hcd->driver->shutdown)
hcd->driver->shutdown(hcd);
}
EXPORT_SYMBOL_GPL(usb_hcd_pci_shutdown);
#ifdef CONFIG_PM_SLEEP
static int check_root_hub_suspended(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct usb_hcd *hcd = pci_get_drvdata(pci_dev);
if (!(hcd->state == HC_STATE_SUSPENDED ||
hcd->state == HC_STATE_HALT)) {
dev_warn(dev, "Root hub is not suspended\n");
return -EBUSY;
}
return 0;
}
static int hcd_pci_suspend(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct usb_hcd *hcd = pci_get_drvdata(pci_dev);
int retval;
/* Root hub suspend should have stopped all downstream traffic,
* and all bus master traffic. And done so for both the interface
* and the stub usb_device (which we check here). But maybe it
* didn't; writing sysfs power/state files ignores such rules...
*/
retval = check_root_hub_suspended(dev);
if (retval)
return retval;
/* We might already be suspended (runtime PM -- not yet written) */
if (pci_dev->current_state != PCI_D0)
return retval;
if (hcd->driver->pci_suspend) {
retval = hcd->driver->pci_suspend(hcd);
suspend_report_result(hcd->driver->pci_suspend, retval);
if (retval)
return retval;
}
synchronize_irq(pci_dev->irq);
/* Downstream ports from this root hub should already be quiesced, so
* there will be no DMA activity. Now we can shut down the upstream
* link (except maybe for PME# resume signaling). We'll enter a
* low power state during suspend_noirq, if the hardware allows.
*/
pci_disable_device(pci_dev);
return retval;
}
static int hcd_pci_suspend_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct usb_hcd *hcd = pci_get_drvdata(pci_dev);
int retval;
retval = check_root_hub_suspended(dev);
if (retval)
return retval;
pci_save_state(pci_dev);
/* If the root hub is HALTed rather than SUSPENDed,
* disallow remote wakeup.
*/
if (hcd->state == HC_STATE_HALT)
device_set_wakeup_enable(dev, 0);
dev_dbg(dev, "wakeup: %d\n", device_may_wakeup(dev));
/* Possibly enable remote wakeup,
* choose the appropriate low-power state, and go to that state.
*/
retval = pci_prepare_to_sleep(pci_dev);
if (retval == -EIO) { /* Low-power not supported */
dev_dbg(dev, "--> PCI D0 legacy\n");
retval = 0;
} else if (retval == 0) {
dev_dbg(dev, "--> PCI %s\n",
pci_power_name(pci_dev->current_state));
} else {
suspend_report_result(pci_prepare_to_sleep, retval);
return retval;
}
#ifdef CONFIG_PPC_PMAC
/* Disable ASIC clocks for USB */
if (machine_is(powermac)) {
struct device_node *of_node;
of_node = pci_device_to_OF_node(pci_dev);
if (of_node)
pmac_call_feature(PMAC_FTR_USB_ENABLE, of_node, 0, 0);
}
#endif
return retval;
}
static int hcd_pci_resume_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
#ifdef CONFIG_PPC_PMAC
/* Reenable ASIC clocks for USB */
if (machine_is(powermac)) {
struct device_node *of_node;
of_node = pci_device_to_OF_node(pci_dev);
if (of_node)
pmac_call_feature(PMAC_FTR_USB_ENABLE,
of_node, 0, 1);
}
#endif
/* Go back to D0 and disable remote wakeup */
pci_back_from_sleep(pci_dev);
return 0;
}
static int resume_common(struct device *dev, bool hibernated)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
struct usb_hcd *hcd = pci_get_drvdata(pci_dev);
int retval;
if (hcd->state != HC_STATE_SUSPENDED) {
dev_dbg(dev, "can't resume, not suspended!\n");
return 0;
}
retval = pci_enable_device(pci_dev);
if (retval < 0) {
dev_err(dev, "can't re-enable after resume, %d!\n", retval);
return retval;
}
pci_set_master(pci_dev);
clear_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
if (hcd->driver->pci_resume) {
/* This call should be made only during system resume,
* not during runtime resume.
*/
wait_for_companions(pci_dev, hcd);
retval = hcd->driver->pci_resume(hcd, hibernated);
if (retval) {
dev_err(dev, "PCI post-resume error %d!\n", retval);
usb_hc_died(hcd);
}
}
return retval;
}
static int hcd_pci_resume(struct device *dev)
{
return resume_common(dev, false);
}
static int hcd_pci_restore(struct device *dev)
{
return resume_common(dev, true);
}
const struct dev_pm_ops usb_hcd_pci_pm_ops = {
.suspend = hcd_pci_suspend,
.suspend_noirq = hcd_pci_suspend_noirq,
.resume_noirq = hcd_pci_resume_noirq,
.resume = hcd_pci_resume,
.freeze = check_root_hub_suspended,
.freeze_noirq = check_root_hub_suspended,
.thaw_noirq = NULL,
.thaw = NULL,
.poweroff = hcd_pci_suspend,
.poweroff_noirq = hcd_pci_suspend_noirq,
.restore_noirq = hcd_pci_resume_noirq,
.restore = hcd_pci_restore,
};
EXPORT_SYMBOL_GPL(usb_hcd_pci_pm_ops);
#endif /* CONFIG_PM_SLEEP */