dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

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: Mark Hounschell <markh@compro.net>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: <stable@kernel.org>
LKML-Reference: <20100121190952.GA32523@linux-os.sc.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
Pallipadi, Venkatesh 2010-01-21 11:09:52 -08:00 committed by Ingo Molnar
parent 3a5fc0e40c
commit 73472a46b5
3 changed files with 22 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/x86/include/asm/hpet.h
View File

@ -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);

8
arch/x86/kernel/hpet.c
View File

@ -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;

13
arch/x86/kernel/quirks.c
View File

@ -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)