| Subject: x86: hpet: Disable MSI on Lenovo W510 |
| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Fri, 30 Sep 2011 20:03:37 +0200 |
| |
| MSI based per cpu timers lose interrupts when intel_idle() is enabled |
| - independent of the c-state. With idle=poll the problem cannot be |
| observed. We have no idea yet, whether this is a W510 specific issue |
| or a general chipset oddity. Blacklist the known problem machine. |
| |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| --- |
| arch/x86/kernel/hpet.c | 27 +++++++++++++++++++++++++++ |
| 1 file changed, 27 insertions(+) |
| |
| --- a/arch/x86/kernel/hpet.c |
| +++ b/arch/x86/kernel/hpet.c |
| @@ -8,6 +8,7 @@ |
| #include <linux/slab.h> |
| #include <linux/hpet.h> |
| #include <linux/init.h> |
| +#include <linux/dmi.h> |
| #include <linux/cpu.h> |
| #include <linux/pm.h> |
| #include <linux/io.h> |
| @@ -573,6 +574,30 @@ static void init_one_hpet_msi_clockevent |
| #define RESERVE_TIMERS 0 |
| #endif |
| |
| +static int __init dmi_disable_hpet_msi(const struct dmi_system_id *d) |
| +{ |
| + hpet_msi_disable = 1; |
| + return 0; |
| +} |
| + |
| +static struct dmi_system_id __initdata dmi_hpet_table[] = { |
| + /* |
| + * MSI based per cpu timers lose interrupts when intel_idle() |
| + * is enabled - independent of the c-state. With idle=poll the |
| + * problem cannot be observed. We have no idea yet, whether |
| + * this is a W510 specific issue or a general chipset oddity. |
| + */ |
| + { |
| + .callback = dmi_disable_hpet_msi, |
| + .ident = "Lenovo W510", |
| + .matches = { |
| + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), |
| + DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad W510"), |
| + }, |
| + }, |
| + {} |
| +}; |
| + |
| static void hpet_msi_capability_lookup(unsigned int start_timer) |
| { |
| unsigned int id; |
| @@ -580,6 +605,8 @@ static void hpet_msi_capability_lookup(u |
| unsigned int num_timers_used = 0; |
| int i; |
| |
| + dmi_check_system(dmi_hpet_table); |
| + |
| if (hpet_msi_disable) |
| return; |
| |