OHCI: work around for nVidia shutdown problem

This patch (as1417) fixes a problem affecting some (or all) nVidia
chipsets.  When the computer is shut down, the OHCI controllers
continue to power the USB buses and evidently they drive a Reset
signal out all their ports.  This prevents attached devices from going
to low power.  Mouse LEDs stay on, for example, which is disconcerting
for users and a drain on laptop batteries.

The fix involves leaving each OHCI controller in the OPERATIONAL state
during system shutdown rather than putting it in the RESET state.
Although this nominally means the controller is running, in fact it's
not doing very much since all the schedules are all disabled.  However
there is ongoing DMA to the Host Controller Communications Area, so
the patch also disables the bus-master capability of all PCI USB
controllers after the shutdown routine runs.

The fix is applied only to nVidia-based PCI OHCI controllers, so it
shouldn't cause problems on systems using other hardware.  As an added
safety measure, in case the kernel encounters one of these running
controllers during boot, the patch changes quirk_usb_handoff_ohci()
(which runs early on during PCI discovery) to reset the controller
before anything bad can happen.

Reported-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Tested-by: Pali Rohár <pali.rohar@gmail.com>
CC: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index c3f98543caaf9d3867fadc756db69346bba32a04..3799573bd385db30aab6db375bab0d506595e9c0 100644 (file)
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -329,8 +329,10 @@ void usb_hcd_pci_shutdown(struct pci_dev *dev)
                return;
 
        if (test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) &&
-                       hcd->driver->shutdown)
+                       hcd->driver->shutdown) {
                hcd->driver->shutdown(hcd);
+               pci_disable_device(dev);
+       }
 }
 EXPORT_SYMBOL_GPL(usb_hcd_pci_shutdown);
 

diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index c3b4ccc7337b54577f6ae0d9c5ab934f9359d27f..8ef3c19443643be07112c9ee7e1cbdba39792ada 100644 (file)
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -398,7 +398,14 @@ ohci_shutdown (struct usb_hcd *hcd)
 
        ohci = hcd_to_ohci (hcd);
        ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
-       ohci_usb_reset (ohci);
+       ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
+
+       /* If the SHUTDOWN quirk is set, don't put the controller in RESET */
+       ohci->hc_control &= (ohci->flags & OHCI_QUIRK_SHUTDOWN ?
+                       OHCI_CTRL_RWC | OHCI_CTRL_HCFS :
+                       OHCI_CTRL_RWC);
+       ohci_writel(ohci, ohci->hc_control, &ohci->regs->control);
+
        /* flush the writes */
        (void) ohci_readl (ohci, &ohci->regs->control);
 }

diff --git a/drivers/usb/host/ohci-pci.c b/drivers/usb/host/ohci-pci.c
index 6bdc8b25a6a10051f29c43bbfef682aefb9a4504..36ee9a666e937af93cb27af0321b5b409cf49929 100644 (file)
--- a/drivers/usb/host/ohci-pci.c
+++ b/drivers/usb/host/ohci-pci.c
@@ -201,6 +201,20 @@ static int ohci_quirk_amd700(struct usb_hcd *hcd)
        return 0;
 }
 
+/* nVidia controllers continue to drive Reset signalling on the bus
+ * even after system shutdown, wasting power.  This flag tells the
+ * shutdown routine to leave the controller OPERATIONAL instead of RESET.
+ */
+static int ohci_quirk_nvidia_shutdown(struct usb_hcd *hcd)
+{
+       struct ohci_hcd *ohci = hcd_to_ohci(hcd);
+
+       ohci->flags |= OHCI_QUIRK_SHUTDOWN;
+       ohci_dbg(ohci, "enabled nVidia shutdown quirk\n");
+
+       return 0;
+}
+
 /*
  * The hardware normally enables the A-link power management feature, which
  * lets the system lower the power consumption in idle states.
@@ -332,6 +346,10 @@ static const struct pci_device_id ohci_pci_quirks[] = {
                PCI_DEVICE(PCI_VENDOR_ID_ATI, 0x4399),
                .driver_data = (unsigned long)ohci_quirk_amd700,
        },
+       {
+               PCI_DEVICE(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID),
+               .driver_data = (unsigned long) ohci_quirk_nvidia_shutdown,
+       },
 
        /* FIXME for some of the early AMD 760 southbridges, OHCI
         * won't work at all.  blacklist them.

diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index 5bf15fed0d9fcd4f4654bb51c7ae38ea82cf905c..51facb985c847801ca3af267aac4887293e18ad3 100644 (file)
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -403,6 +403,7 @@ struct ohci_hcd {
 #define        OHCI_QUIRK_HUB_POWER    0x100                   /* distrust firmware power/oc setup */
 #define        OHCI_QUIRK_AMD_ISO      0x200                   /* ISO transfers*/
 #define        OHCI_QUIRK_AMD_PREFETCH 0x400                   /* pre-fetch for ISO transfer */
+#define        OHCI_QUIRK_SHUTDOWN     0x800                   /* nVidia power bug */
        // there are also chip quirks/bugs in init logic
 
        struct work_struct      nec_work;       /* Worker for NEC quirk */

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 83b5f9cea85ac9f43af8d3b1eb87a259517cc05c..464ed977b45d9d0388af38e565fb0fe07966c712 100644 (file)
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -169,6 +169,7 @@ static int __devinit mmio_resource_enabled(struct pci_dev *pdev, int idx)
 static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)
 {
        void __iomem *base;
+       u32 control;
 
        if (!mmio_resource_enabled(pdev, 0))
                return;
@@ -177,10 +178,14 @@ static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)
        if (base == NULL)
                return;
 
+       control = readl(base + OHCI_CONTROL);
+
 /* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
-#ifndef __hppa__
-{
-       u32 control = readl(base + OHCI_CONTROL);
+#ifdef __hppa__
+#define        OHCI_CTRL_MASK          (OHCI_CTRL_RWC | OHCI_CTRL_IR)
+#else
+#define        OHCI_CTRL_MASK          OHCI_CTRL_RWC
+
        if (control & OHCI_CTRL_IR) {
                int wait_time = 500; /* arbitrary; 5 seconds */
                writel(OHCI_INTR_OC, base + OHCI_INTRENABLE);
@@ -194,13 +199,12 @@ static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)
                        dev_warn(&pdev->dev, "OHCI: BIOS handoff failed"
                                        " (BIOS bug?) %08x\n",
                                        readl(base + OHCI_CONTROL));
-
-               /* reset controller, preserving RWC */
-               writel(control & OHCI_CTRL_RWC, base + OHCI_CONTROL);
        }
-}
 #endif
 
+       /* reset controller, preserving RWC (and possibly IR) */
+       writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL);
+
        /*
         * disable interrupts
         */