[PATCH] intel_idle: PCI quirk to prevent Lenovo Ideapad s10-3 boot hang

[Tim Gardner]

On 09/27/2010 04:24 AM, Ike Panhc wrote:
> From: Len Brown<len.brown at intel.com>
>
> When the Lenovo Ideapad S10-3 is booted with HT enabled,
> it hits a boot hang in the intel_idle driver.
>
> This occurs when entering ATM-C4 for the first time,
> unless BM_STS is first cleared.
>
> acpi_idle doesn't see this because it first checks
> and clears BM_STS, but it would hit the same hang
> if that check were disabled.
>
> http://bugs.meego.com/show_bug.cgi?id=7093
> BugLink: http://launchpad.net/bugs/634702
>
> Signed-off-by: Len Brown<len.brown at intel.com>
> Signed-off-by: Ike Panhc<ike.pan at canonical.com>
> ---
>   drivers/pci/quirks.c |   20 ++++++++++++++++++++
>   1 files changed, 20 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index e28524e..2a73ceb 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -150,6 +150,26 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NEC,	PCI_DEVICE_ID_NEC_CBUS_2,	quirk_isa_d
>   DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NEC,	PCI_DEVICE_ID_NEC_CBUS_3,	quirk_isa_dma_hangs);
>
>   /*
> + * Intel NM10 "TigerPoint" LPC PM1a_STS.BM_STS must be clear
> + * for some HT machines to use C4 w/o hanging.
> + */
> +static void __devinit quirk_tigerpoint_bm_sts(struct pci_dev *dev)
> +{
> +	u32 pmbase;
> +	u16 pm1a;
> +
> +	pci_read_config_dword(dev, 0x40,&pmbase);
> +	pmbase = pmbase&  0xff80;
> +	pm1a = inw(pmbase);
> +
> +	if (pm1a&  0x10) {
> +		dev_info(&dev->dev, FW_BUG "TigerPoint LPC.BM_STS cleared\n");
> +		outw(0x10, pmbase);
> +	}
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_TGP_LPC, quirk_tigerpoint_bm_sts);
> +
> +/*
>    *	Chipsets where PCI->PCI transfers vanish or hang
>    */
>   static void __devinit quirk_nopcipci(struct pci_dev *dev)

This looks like it should have had a 'Cc: stable at kernel.org'. I presume 
Len has sent this to Jesse Barnes as he is the PCI subsystem maintainer. 
Perhaps you could ask him to update the commit log with that Cc.

Acked-by: Tim Gardner <tim.gardner at canonical.com>

-- 
Tim Gardner tim.gardner at canonical.com