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authorPallipadi, Venkatesh <venkatesh.pallipadi@intel.com>2010-01-21 11:09:52 -0800
committerIngo Molnar <mingo@elte.hu>2010-01-23 06:21:58 +0100
commit73472a46b5b28116b145fb5fc05242c1aa8e1461 (patch)
treebbcb6174edb2ea3c94e64bbfe7f92f3f128d96d3 /arch/x86/kernel/hpet.c
parent3a5fc0e40cb467e692737bc798bc99773c81e1e2 (diff)
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>
Diffstat (limited to 'arch/x86/kernel/hpet.c')
-rw-r--r--arch/x86/kernel/hpet.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index ba6e6588460..ad80a1c718c 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -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;