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Message-ID: <5035B1F6.3030703@gmail.com>
Date: Wed, 22 Aug 2012 22:30:46 -0600
From: Robert Hancock <hancockrwd@...il.com>
To: Sarah Sharp <sarah.a.sharp@...ux.intel.com>
CC: Denis Turischev <denis@...pulab.co.il>, linux-usb@...r.kernel.org,
Greg KH <gregkh@...uxfoundation.org>,
linux-kernel@...r.kernel.org
Subject: Re: [RFT] xhci: Switch PPT ports to EHCI on shutdown.
On 08/07/2012 11:39 AM, Sarah Sharp wrote:
> The Intel desktop boards DH77EB and DH77DF have a hardware issue that
> can be worked around by BIOS. If the USB ports are switched to xHCI on
> shutdown, the xHCI host will send a spurious interrupt, which will wake
> the system. Some BIOS will work around this, but not all.
>
> The bug can be avoided if the USB ports are switched back to EHCI on
> shutdown. The Intel Windows driver switches the ports back to EHCI, so
> change the Linux xHCI driver to do the same.
>
> Unfortunately, we can't tell the two effected boards apart from other
> working motherboards, because the vendors will change the DMI strings
> for the DH77EB and DH77DF boards to their own custom names. One example
> is Compulab's mini-desktop, the Intense-PC. Instead, key off the
> Panther Point xHCI host PCI vendor and device ID, and switch the ports
> over for all PPT xHCI hosts.
>
> The only impact this will have on non-effected boards is to add a couple
> hundred milliseconds delay on boot when the BIOS has to switch the ports
> over from EHCI to xHCI.
>
> This patch should be backported to kernels as old as 3.0, that contain
> the commit 69e848c2090aebba5698a1620604c7dccb448684 "Intel xhci: Support
> EHCI/xHCI port switching."
>
> Signed-off-by: Sarah Sharp <sarah.a.sharp@...ux.intel.com>
> Reported-by: Denis Turischev <denis@...pulab.co.il>
> Cc: stable@...r.kernel.org
> ---
> drivers/usb/host/pci-quirks.c | 7 +++++++
> drivers/usb/host/pci-quirks.h | 1 +
> drivers/usb/host/xhci-pci.c | 9 +++++++++
> drivers/usb/host/xhci.c | 3 +++
> drivers/usb/host/xhci.h | 1 +
> 5 files changed, 21 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
> index df0828c..c5e9e4a 100644
> --- a/drivers/usb/host/pci-quirks.c
> +++ b/drivers/usb/host/pci-quirks.c
> @@ -800,6 +800,13 @@ void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
> }
> EXPORT_SYMBOL_GPL(usb_enable_xhci_ports);
>
> +void usb_disable_xhci_ports(struct pci_dev *xhci_pdev)
> +{
> + pci_write_config_dword(xhci_pdev, USB_INTEL_USB3_PSSEN, 0x0);
> + pci_write_config_dword(xhci_pdev, USB_INTEL_XUSB2PR, 0x0);
> +}
> +EXPORT_SYMBOL_GPL(usb_disable_xhci_ports);
> +
> /**
> * PCI Quirks for xHCI.
> *
> diff --git a/drivers/usb/host/pci-quirks.h b/drivers/usb/host/pci-quirks.h
> index b1002a8..ef004a5 100644
> --- a/drivers/usb/host/pci-quirks.h
> +++ b/drivers/usb/host/pci-quirks.h
> @@ -10,6 +10,7 @@ void usb_amd_quirk_pll_disable(void);
> void usb_amd_quirk_pll_enable(void);
> bool usb_is_intel_switchable_xhci(struct pci_dev *pdev);
> void usb_enable_xhci_ports(struct pci_dev *xhci_pdev);
> +void usb_disable_xhci_ports(struct pci_dev *xhci_pdev);
> #else
> static inline void usb_amd_quirk_pll_disable(void) {}
> static inline void usb_amd_quirk_pll_enable(void) {}
> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> index 92eaff6..9bfd4ca11 100644
> --- a/drivers/usb/host/xhci-pci.c
> +++ b/drivers/usb/host/xhci-pci.c
> @@ -94,6 +94,15 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
> xhci->quirks |= XHCI_EP_LIMIT_QUIRK;
> xhci->limit_active_eps = 64;
> xhci->quirks |= XHCI_SW_BW_CHECKING;
> + /*
> + * PPT desktop boards DH77EB and DH77DF will power back on after
> + * a few seconds of being shutdown. The fix for this is to
> + * switch the ports from xHCI to EHCI on shutdown. We can't use
> + * DMI information to find those particular boards (since each
> + * vendor will change the board name), so we have to key off all
> + * PPT chipsets.
> + */
> + xhci->quirks |= XHCI_SPURIOUS_REBOOT;
> }
> if (pdev->vendor == PCI_VENDOR_ID_ETRON &&
> pdev->device == PCI_DEVICE_ID_ASROCK_P67) {
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index 95394e5..81aa10c 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -659,6 +659,9 @@ void xhci_shutdown(struct usb_hcd *hcd)
> {
> struct xhci_hcd *xhci = hcd_to_xhci(hcd);
>
> + if (xhci->quirks && XHCI_SPURIOUS_REBOOT)
> + usb_disable_xhci_ports(to_pci_dev(hcd->self.controller));
This looks like a typo, think it should be & not &&. With this code, it
appears the quirk will always be triggered since XHCI_SPURIOUS_REBOOT is
non-zero.
> +
> spin_lock_irq(&xhci->lock);
> xhci_halt(xhci);
> spin_unlock_irq(&xhci->lock);
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index 96f49db..c713256 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -1494,6 +1494,7 @@ struct xhci_hcd {
> #define XHCI_TRUST_TX_LENGTH (1 << 10)
> #define XHCI_LPM_SUPPORT (1 << 11)
> #define XHCI_INTEL_HOST (1 << 12)
> +#define XHCI_SPURIOUS_REBOOT (1 << 13)
> unsigned int num_active_eps;
> unsigned int limit_active_eps;
> /* There are two roothubs to keep track of bus suspend info for */
>
--
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