Hi all, I take the following weekday as personal leave days, so I send out the patch earlier for discussion. I'll read email next week. Best regards, AceLan Kao. 2012/7/4 AceLan Kao <acelan.kao@xxxxxxxxxxxxx>: > Attempt to suspend some ASUS systems causes hang. Power cycle required > to recover. > The root cause of this issue is result from the the BIOS will try to > disable USB which is already disabled by the driver. > BIOS will check the EHCI controller's PCI COMMAND register, > if it's not zero, then BIOS will think the USB is not disabled yet, > so it will try to disable USB again, and then hang in the BIOS code. > To resolve this, we should clear the EHCI controller's PCI COMMAND > register before entering S3. And this does no harm to the system, > since it'll switch off the power after enter S3, and the value in the > register will be reset by BIOS after wakeup. > > Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=43064 > BugLink: http://bugs.launchpad.net/bugs/951143 > > Signed-off-by: AceLan Kao <acelan.kao@xxxxxxxxxxxxx> > --- > drivers/pci/quirks.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index 194b243a..d1bb4db 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -2955,6 +2955,25 @@ static void __devinit asus_ehci_no_d3(struct pci_dev *dev) > DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1c26, asus_ehci_no_d3); > DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x1c2d, asus_ehci_no_d3); > > +/* > + * ASUS BIOS will check the EHCI controller's PCI COMMAND register to see > + * if the value is all zero. If not, BIOS will think the USB is not disabled > + * and will try to disable USB. But, actually, USB is disabled by the driver > + * while entering S3, so it'll hang in BIOS when it try to disable USB. > + * Since it's going to enter S3, so it does no harm to clear the EHCI > + * controller's PCI COMMAND register. And the value of the PCI COMMAND > + * register value will be restored correctly after S3. > + */ > +static void asus_clear_pci_command(struct pci_dev *dev) > +{ > + if (dev->subsystem_vendor != PCI_VENDOR_ID_ASUSTEK) > + return; > + > + pci_write_config_word(dev, PCI_COMMAND, 0); > +} > +DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_AMD, 0x7808, asus_clear_memory_bit); > +DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_ATI, 0x4396, asus_clear_memory_bit); > + > static void pci_do_fixups(struct pci_dev *dev, struct pci_fixup *f, > struct pci_fixup *end) > { > -- > 1.7.9.5 > -- Chia-Lin Kao(AceLan) http://blog.acelan.idv.tw/ E-Mail: acelan.kaoATcanonical.com (s/AT/@/) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
