Commit-ID: 73472a46b5b28116b145fb5fc05242c1aa8e1461
Gitweb: http://git.kernel.org/tip/73472a46b5b28116b145fb5fc05242c1aa8e1461
Author: Pallipadi, Venkatesh <venkatesh.pallipadi@xxxxxxxxx>
AuthorDate: Thu, 21 Jan 2010 11:09:52 -0800
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Sat, 23 Jan 2010 06:21:58 +0100
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@xxxxxxxxxx>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Cc: <stable@xxxxxxxxxx>
LKML-Reference: <20100121190952.GA32523@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx>
---
arch/x86/include/asm/hpet.h | 1 +
arch/x86/kernel/hpet.c | 8 ++++++++
arch/x86/kernel/quirks.c | 13 +++++++++++++
3 files changed, 22 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/hpet.h b/arch/x86/include/asm/hpet.h
index 5d89fd2..1d5c08a 100644
--- a/arch/x86/include/asm/hpet.h
+++ b/arch/x86/include/asm/hpet.h
@@ -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);
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index ba6e658..ad80a1c 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;
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 18093d7..12e9fea 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -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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