From 8db491490b88c8b016b41ad56ac980c4cbb06d7a Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Wed, 27 Mar 2013 06:59:59 -0400 Subject: firewire: ohci: Check LPS before register access on pci removal A pci device can be removed while in its suspended state. If the ohci host controller is suspended, the PHY is also in low-power mode and LPS is disabled. If LPS is disabled, most of the host registers aren't accessible, including IntMaskClear. Furthermore, access to these registers when LPS is disabled can cause hard lockups on some hardware. Since interrupts are already disabled in this mode, further action is unnecessary. Test LPS before attempting to write IntMaskClear to disable interrupts. [Stefan R: whitespace changes] Signed-off-by: Peter Hurley Signed-off-by: Stefan Richter --- drivers/firewire/ohci.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'drivers/firewire') diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 48889353723..673c8970749 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -3712,11 +3712,16 @@ static int pci_probe(struct pci_dev *dev, static void pci_remove(struct pci_dev *dev) { - struct fw_ohci *ohci; + struct fw_ohci *ohci = pci_get_drvdata(dev); - ohci = pci_get_drvdata(dev); - reg_write(ohci, OHCI1394_IntMaskClear, ~0); - flush_writes(ohci); + /* + * If the removal is happening from the suspend state, LPS won't be + * enabled and host registers (eg., IntMaskClear) won't be accessible. + */ + if (reg_read(ohci, OHCI1394_HCControlSet) & OHCI1394_HCControl_LPS) { + reg_write(ohci, OHCI1394_IntMaskClear, ~0); + flush_writes(ohci); + } cancel_work_sync(&ohci->bus_reset_work); fw_core_remove_card(&ohci->card); -- cgit v1.2.3