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SubjectRe: [39/45] OHCI: work around for nVidia shutdown problem
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On Fri, Nov 19, 2010 at 10:43 PM, Greg KH <gregkh@suse.de> wrote:
> 2.6.32-stable review patch.  If anyone has any objections, please let us know.
>
> ------------------
>
> From: Alan Stern <stern@rowland.harvard.edu>
>
> commit 3df7169e73fc1d71a39cffeacc969f6840cdf52b upstream.
>
> 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>
> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
>
> ---
>  drivers/usb/core/hcd-pci.c    |    4 +++-
>  drivers/usb/host/ohci-hcd.c   |    9 ++++++++-
>  drivers/usb/host/ohci-pci.c   |   18 ++++++++++++++++++
>  drivers/usb/host/ohci.h       |    1 +
>  drivers/usb/host/pci-quirks.c |   18 +++++++++++-------
>  5 files changed, 41 insertions(+), 9 deletions(-)
>
> --- a/drivers/usb/core/hcd-pci.c
> +++ b/drivers/usb/core/hcd-pci.c
> @@ -197,8 +197,10 @@ void usb_hcd_pci_shutdown(struct pci_dev
>        if (!hcd)
>                return;
>
> -       if (hcd->driver->shutdown)
> +       if (hcd->driver->shutdown) {
>                hcd->driver->shutdown(hcd);
> +               pci_disable_device(dev);
> +       }
>  }
>  EXPORT_SYMBOL_GPL(usb_hcd_pci_shutdown);
>
> --- 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);
>  }
> --- 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_
>        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_p
>                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.
> --- 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 */
> --- a/drivers/usb/host/pci-quirks.c
> +++ b/drivers/usb/host/pci-quirks.c
> @@ -169,6 +169,7 @@ static int __devinit mmio_resource_enabl
>  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_
>        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_
>                        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
>         */
>
>

Hello,

i think it was back when my distro got linux 2.6.37 that i noticed the
usb devices are not powered off anymore during shutdown. i was(/am)
lazy and didn't bother to investigate, until today. i found
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/42149 which
mentioned this patch (and that it was supposedly added in 2.6.37).

i boldly reversed this part for my current kernel (2.6.38.1) and build it*:

--- 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);
}
lo and behold, my usb devices are now powered off again at shutdown.

this was my first ever hack on the linux code, and i have no real idea
what i'm doing here...
but if theres anything i can do to help to solve this problem, please
let me know!

lspci -v | grep USB
00:0b.0 USB Controller: nVidia Corporation MCP51 USB Controller (rev
a3) (prog-if 10 [OHCI])
00:0b.1 USB Controller: nVidia Corporation MCP51 USB Controller (rev
a3) (prog-if 20 [EHCI])

cheers
.andre

* by following this method
https://wiki.archlinux.org/index.php/Kernel_Compilation
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