Commit d79a5f80 authored by Carlos Corbacho's avatar Carlos Corbacho Committed by Thomas Gleixner
Browse files

x86: Force enable HPET for CK804 (nForce 4) chipsets 



This patch adds a quirk from LinuxBIOS to force enable HPET on
the nVidia CK804 (nForce 4) chipset.

This quirk can very likely support more than just nForce 4
(LinuxBIOS use the same code for nForce 5), and possibly nForce 3,
but I don't have those chipsets, so cannot add and test them.

Tested on an Abit KN9 (CK804).

Signed-off-by: default avatarCarlos Corbacho <cathectic@gmail.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>

 Documentation/kernel-parameters.txt |    3 +-
 arch/x86/kernel/quirks.c            |   37 +++++++++++++++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 2 deletions(-)
parent fa76dab9

Documentation/kernel-parameters.txt

+2 −1
Original line number Diff line number Diff line
@@ -422,7 +422,8 @@ and is between 256 and 4096 characters. It is defined in the file 
	hpet=		[X86-32,HPET] option to control HPET usage

			Format: { enable (default) | disable | force }

			disable: disable HPET and use PIT instead

			force: allow force enabled of undocumented chips (ICH4, VIA)

			force: allow force enabled of undocumented chips (ICH4,

			VIA, nVidia)



	com20020=	[HW,NET] ARCnet - COM20020 chipset

			Format:

arch/x86/kernel/quirks.c

+36 −1
Original line number Diff line number Diff line
@@ -60,7 +60,8 @@ static enum { 
	NONE_FORCE_HPET_RESUME,

	OLD_ICH_FORCE_HPET_RESUME,

	ICH_FORCE_HPET_RESUME,

	VT8237_FORCE_HPET_RESUME

	VT8237_FORCE_HPET_RESUME,

	NVIDIA_FORCE_HPET_RESUME,

} force_hpet_resume_type;



static void __iomem *rcba_base;
@@ -321,6 +322,37 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235, 
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8237,

			 vt8237_force_enable_hpet);



/*

 * Undocumented chipset feature taken from LinuxBIOS.

 */

static void nvidia_force_hpet_resume(void)

{

	pci_write_config_dword(cached_dev, 0x44, 0xfed00001);

	printk(KERN_DEBUG "Force enabled HPET at resume\n");

}



static void nvidia_force_enable_hpet(struct pci_dev *dev)

{

	u32 uninitialized_var(val);



	if (!hpet_force_user || hpet_address || force_hpet_address)

		return;



	pci_write_config_dword(dev, 0x44, 0xfed00001);

	pci_read_config_dword(dev, 0x44, &val);

	force_hpet_address = val & 0xfffffffe;

	force_hpet_resume_type = NVIDIA_FORCE_HPET_RESUME;

	printk(KERN_DEBUG "Force enabled HPET at base address 0x%lx\n",

		force_hpet_address);

	cached_dev = dev;

	return;

}



/* ISA Bridges */

DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NVIDIA, 0x0050,

			nvidia_force_enable_hpet);

DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NVIDIA, 0x0051,

			nvidia_force_enable_hpet);



void force_hpet_resume(void)

{
@@ -334,6 +366,9 @@ void force_hpet_resume(void) 
	    case VT8237_FORCE_HPET_RESUME:

		return vt8237_force_hpet_resume();



	    case NVIDIA_FORCE_HPET_RESUME:

		return nvidia_force_hpet_resume();



	    default:

		break;

	}

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