Commit 73472a46 authored by Pallipadi, Venkatesh's avatar Pallipadi, Venkatesh Committed by Ingo Molnar
Browse files

x86: Disable HPET MSI on ATI SB700/SB800 

HPET MSI on platforms with ATI SB700/SB800 as they seem to have some
side-effects on floppy DMA. Do not use HPET MSI on such platforms.

Original problem report from Mark Hounschell
http://lkml.indiana.edu/hypermail/linux/kernel/0912.2/01118.html



[ This patch needs to go to stable as well. But, there are some
  conflicts that prevents the patch from going as is. I can
  rebase/resubmit to stable once the patch goes upstream.
  hpa: still Cc:'ing stable@ as an FYI. ]

Tested-by: default avatarMark Hounschell <markh@compro.net>
Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: <stable@kernel.org>
LKML-Reference: <20100121190952.GA32523@linux-os.sc.intel.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 3a5fc0e4

arch/x86/include/asm/hpet.h

+1 −0
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ extern unsigned long hpet_address; 
extern unsigned long force_hpet_address;

extern u8 hpet_blockid;

extern int hpet_force_user;

extern u8 hpet_msi_disable;

extern int is_hpet_enabled(void);

extern int hpet_enable(void);

extern void hpet_disable(void);

arch/x86/kernel/hpet.c

+8 −0
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ 
 */

unsigned long				hpet_address;

u8					hpet_blockid; /* OS timer block num */

u8					hpet_msi_disable;



#ifdef CONFIG_PCI_MSI

static unsigned long			hpet_num_timers;

#endif
@@ -596,6 +598,9 @@ static void hpet_msi_capability_lookup(unsigned int start_timer) 
	unsigned int num_timers_used = 0;

	int i;



	if (hpet_msi_disable)

		return;



	if (boot_cpu_has(X86_FEATURE_ARAT))

		return;

	id = hpet_readl(HPET_ID);
@@ -928,6 +933,9 @@ static __init int hpet_late_init(void) 
	hpet_reserve_platform_timers(hpet_readl(HPET_ID));

	hpet_print_config();



	if (hpet_msi_disable)

		return 0;



	if (boot_cpu_has(X86_FEATURE_ARAT))

		return 0;

arch/x86/kernel/quirks.c

+13 −0
Original line number Diff line number Diff line
@@ -491,6 +491,19 @@ void force_hpet_resume(void) 
		break;

	}

}



/*

 * HPET MSI on some boards (ATI SB700/SB800) has side effect on

 * floppy DMA. Disable HPET MSI on such platforms.

 */

static void force_disable_hpet_msi(struct pci_dev *unused)

{

	hpet_msi_disable = 1;

}



DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS,

			 force_disable_hpet_msi);



#endif



#if defined(CONFIG_PCI) && defined(CONFIG_NUMA)

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