kernel-ark/drivers/usb/core/hcd-pci.c
Benjamin Herrenschmidt 8de9840265 [PATCH] USB: Fix USB suspend/resume crasher (#2)
This patch closes the IRQ race and makes various other OHCI & EHCI code
path safer vs. suspend/resume.
I've been able to (finally !) successfully suspend and resume various
Mac models, with or without USB mouse plugged, or plugging while asleep,
or unplugging while asleep etc... all without a crash.

Alan, please verify the UHCI bit I did, I only verified that it builds.
It's very simple so I wouldn't expect any issue there. If you aren't
confident, then just drop the hunks that change uhci-hcd.c

I also made the patch a little bit more "safer" by making sure the store
to the interrupt register that disables interrupts is not posted before
I set the flag and drop the spinlock.

Without this patch, you cannot reliably sleep/wakeup any recent Mac, and
I suspect PCs have some more sneaky issues too (they don't frankly crash
with machine checks because x86 tend to silently swallow PCI errors but
that won't last afaik, at least PCI Express will blow up in those
situations, but the USB code may still misbehave).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-11-29 21:39:23 -08:00

414 lines
11 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/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/usb.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"
#include "hcd.h"
/* PCI-based HCs are common, but plenty of non-PCI HCs are used too */
/*-------------------------------------------------------------------------*/
/* 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 || !(driver = (struct hc_driver *) id->driver_data))
return -EINVAL;
if (pci_enable_device (dev) < 0)
return -ENODEV;
dev->current_state = PCI_D0;
dev->dev.power.power_state = PMSG_ON;
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 err1;
}
}
pci_set_master (dev);
retval = usb_add_hcd (hcd, dev->irq, SA_SHIRQ);
if (retval != 0)
goto err4;
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:
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 (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;
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);
}
usb_put_hcd (hcd);
pci_disable_device(dev);
}
EXPORT_SYMBOL (usb_hcd_pci_remove);
#ifdef CONFIG_PM
/**
* usb_hcd_pci_suspend - power management suspend of a PCI-based HCD
* @dev: USB Host Controller being suspended
* @message: semantics in flux
*
* Store this function in the HCD's struct pci_driver as suspend().
*/
int usb_hcd_pci_suspend (struct pci_dev *dev, pm_message_t message)
{
struct usb_hcd *hcd;
int retval = 0;
int has_pci_pm;
hcd = pci_get_drvdata(dev);
/* 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...
*
* We must ignore the FREEZE vs SUSPEND distinction here, because
* otherwise the swsusp will save (and restore) garbage state.
*/
if (hcd->self.root_hub->dev.power.power_state.event == PM_EVENT_ON)
return -EBUSY;
if (hcd->driver->suspend) {
retval = hcd->driver->suspend(hcd, message);
if (retval) {
dev_dbg (&dev->dev, "PCI pre-suspend fail, %d\n",
retval);
goto done;
}
}
synchronize_irq(dev->irq);
/* FIXME until the generic PM interfaces change a lot more, this
* can't use PCI D1 and D2 states. For example, the confusion
* between messages and states will need to vanish, and messages
* will need to provide a target system state again.
*
* It'll be important to learn characteristics of the target state,
* especially on embedded hardware where the HCD will often be in
* charge of an external VBUS power supply and one or more clocks.
* Some target system states will leave them active; others won't.
* (With PCI, that's often handled by platform BIOS code.)
*/
/* even when the PCI layer rejects some of the PCI calls
* below, HCs can try global suspend and reduce DMA traffic.
* PM-sensitive HCDs may already have done this.
*/
has_pci_pm = pci_find_capability(dev, PCI_CAP_ID_PM);
/* 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) and enter some PCI
* low power state, if the hardware allows.
*/
if (hcd->state == HC_STATE_SUSPENDED) {
/* no DMA or IRQs except when HC is active */
if (dev->current_state == PCI_D0) {
pci_save_state (dev);
pci_disable_device (dev);
}
if (!has_pci_pm) {
dev_dbg (hcd->self.controller, "--> PCI D0/legacy\n");
goto done;
}
/* NOTE: dev->current_state becomes nonzero only here, and
* only for devices that support PCI PM. Also, exiting
* PCI_D3 (but not PCI_D1 or PCI_D2) is allowed to reset
* some device state (e.g. as part of clock reinit).
*/
retval = pci_set_power_state (dev, PCI_D3hot);
if (retval == 0) {
dev_dbg (hcd->self.controller, "--> PCI D3\n");
/* Ignore these return values. We rely on pci code to
* reject requests the hardware can't implement, rather
* than coding the same thing.
*/
(void) pci_enable_wake (dev, PCI_D3hot, hcd->remote_wakeup);
(void) pci_enable_wake (dev, PCI_D3cold, hcd->remote_wakeup);
} else {
dev_dbg (&dev->dev, "PCI D3 suspend fail, %d\n",
retval);
(void) usb_hcd_pci_resume (dev);
}
} else {
dev_dbg (hcd->self.controller, "hcd state %d; not suspended\n",
hcd->state);
WARN_ON(1);
retval = -EINVAL;
}
done:
if (retval == 0) {
dev->dev.power.power_state = PMSG_SUSPEND;
#ifdef CONFIG_PPC_PMAC
/* Disable ASIC clocks for USB */
if (_machine == _MACH_Pmac) {
struct device_node *of_node;
of_node = pci_device_to_OF_node (dev);
if (of_node)
pmac_call_feature(PMAC_FTR_USB_ENABLE,
of_node, 0, 0);
}
#endif
}
return retval;
}
EXPORT_SYMBOL (usb_hcd_pci_suspend);
/**
* usb_hcd_pci_resume - power management resume of a PCI-based HCD
* @dev: USB Host Controller being resumed
*
* Store this function in the HCD's struct pci_driver as resume().
*/
int usb_hcd_pci_resume (struct pci_dev *dev)
{
struct usb_hcd *hcd;
int retval;
hcd = pci_get_drvdata(dev);
if (hcd->state != HC_STATE_SUSPENDED) {
dev_dbg (hcd->self.controller,
"can't resume, not suspended!\n");
return 0;
}
#ifdef CONFIG_PPC_PMAC
/* Reenable ASIC clocks for USB */
if (_machine == _MACH_Pmac) {
struct device_node *of_node;
of_node = pci_device_to_OF_node (dev);
if (of_node)
pmac_call_feature (PMAC_FTR_USB_ENABLE,
of_node, 0, 1);
}
#endif
/* NOTE: chip docs cover clean "real suspend" cases (what Linux
* calls "standby", "suspend to RAM", and so on). There are also
* dirty cases when swsusp fakes a suspend in "shutdown" mode.
*/
if (dev->current_state != PCI_D0) {
#ifdef DEBUG
int pci_pm;
u16 pmcr;
pci_pm = pci_find_capability(dev, PCI_CAP_ID_PM);
pci_read_config_word(dev, pci_pm + PCI_PM_CTRL, &pmcr);
pmcr &= PCI_PM_CTRL_STATE_MASK;
if (pmcr) {
/* Clean case: power to USB and to HC registers was
* maintained; remote wakeup is easy.
*/
dev_dbg(hcd->self.controller, "resume from PCI D%d\n",
pmcr);
} else {
/* Clean: HC lost Vcc power, D0 uninitialized
* + Vaux may have preserved port and transceiver
* state ... for remote wakeup from D3cold
* + or not; HCD must reinit + re-enumerate
*
* Dirty: D0 semi-initialized cases with swsusp
* + after BIOS init
* + after Linux init (HCD statically linked)
*/
dev_dbg(hcd->self.controller,
"PCI D0, from previous PCI D%d\n",
dev->current_state);
}
#endif
/* yes, ignore these results too... */
(void) pci_enable_wake (dev, dev->current_state, 0);
(void) pci_enable_wake (dev, PCI_D3cold, 0);
} else {
/* Same basic cases: clean (powered/not), dirty */
dev_dbg(hcd->self.controller, "PCI legacy resume\n");
}
/* NOTE: the PCI API itself is asymmetric here. We don't need to
* pci_set_power_state(PCI_D0) since that's part of re-enabling;
* but that won't re-enable bus mastering. Yet pci_disable_device()
* explicitly disables bus mastering...
*/
retval = pci_enable_device (dev);
if (retval < 0) {
dev_err (hcd->self.controller,
"can't re-enable after resume, %d!\n", retval);
return retval;
}
pci_set_master (dev);
pci_restore_state (dev);
dev->dev.power.power_state = PMSG_ON;
clear_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
if (hcd->driver->resume) {
retval = hcd->driver->resume(hcd);
if (retval) {
dev_err (hcd->self.controller,
"PCI post-resume error %d!\n", retval);
usb_hc_died (hcd);
}
}
return retval;
}
EXPORT_SYMBOL (usb_hcd_pci_resume);
#endif /* CONFIG_PM */