On some lenovo laptop, playing with the bus master arbitration

makes them hang. Disable that for now.

diff --git a/master/disable-abr b/master/disable-abr
new file mode 100644 (file)
index 0000000..c9eedc3
--- /dev/null
+++ b/master/disable-abr
@@ -0,0 +1,47 @@
+diff --git a/xen/arch/x86/acpi/cpu_idle.c b/xen/arch/x86/acpi/cpu_idle.c
+index 4bab139..839532b 100644
+--- a/xen/arch/x86/acpi/cpu_idle.c
++++ b/xen/arch/x86/acpi/cpu_idle.c
+@@ -184,10 +184,12 @@ static int acpi_idle_bm_check(void)
+     return bm_status;
+ }
+ 
++#if 0
+ static struct {
+     spinlock_t lock;
+     unsigned int count;
+ } c3_cpu_status = { .lock = SPIN_LOCK_UNLOCKED };
++#endif
+ 
+ static void acpi_processor_idle(void)
+ {
+@@ -282,6 +284,7 @@ static void acpi_processor_idle(void)
+          */
+         if ( power->flags.bm_check && power->flags.bm_control )
+         {
++#if 0
+             spin_lock(&c3_cpu_status.lock);
+             if ( ++c3_cpu_status.count == num_online_cpus() )
+             {
+@@ -292,6 +295,7 @@ static void acpi_processor_idle(void)
+                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
+             }
+             spin_unlock(&c3_cpu_status.lock);
++#endif
+         }
+         else if ( !power->flags.bm_check )
+         {
+@@ -323,11 +327,13 @@ static void acpi_processor_idle(void)
+ 
+         if ( power->flags.bm_check && power->flags.bm_control )
+         {
++#if 0
+             /* Enable bus master arbitration */
+             spin_lock(&c3_cpu_status.lock);
+             if ( c3_cpu_status.count-- == num_online_cpus() )
+                 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
+             spin_unlock(&c3_cpu_status.lock);
++#endif
+         }
+ 
+         /* Re-enable interrupts */

diff --git a/master/series b/master/series
index 541c9af817fa0fff2ac2c6a341f28aaed72d39a7..9b86abe486f624f5625035fa50fd6f1ed1c203af 100644 (file)
--- a/master/series
+++ b/master/series
@@ -13,3 +13,4 @@ remove-fixed-host-bridge-check
 mtrr-changes
 video-memory-workaround
 tools-hvm-info
+disable-abr