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authorLen Brown <len.brown@intel.com>2009-05-07 22:19:45 -0400
committerLen Brown <len.brown@intel.com>2009-05-15 22:44:05 -0400
commit815ab0fd40579ad2aa42058298073503648762b9 (patch)
treeb9e00755f79f98b29b27b711c50ee9d46e1e9dc2 /drivers/acpi/processor_idle.c
parent413f81eba35d6ede9289b0c8a920c013a84fac71 (diff)
ACPI: suspend: restore BM_RLD on resume
In 2.6.29, 31878dd86b7df9a147f5e6cc6e07092b4308782b "ACPI: remove BM_RLD access from idle entry path" moved BM_RLD initialization to init-time from run time. But we discovered that some BIOS do not restore BM_RLD after suspend, causing device errors on C3 and C4 after resume. So now the kernel restores BM_RLD. http://bugzilla.kernel.org/show_bug.cgi?id=13032 Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/processor_idle.c')
-rw-r--r--drivers/acpi/processor_idle.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index f7ca8c55956b..c1d59cfdb5fb 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -202,15 +202,38 @@ static void acpi_state_timer_broadcast(struct acpi_processor *pr,
* Suspend / resume control
*/
static int acpi_idle_suspend;
+static u32 saved_bm_rld;
+
+static void acpi_idle_bm_rld_save(void)
+{
+ acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
+}
+static void acpi_idle_bm_rld_restore(void)
+{
+ u32 resumed_bm_rld;
+
+ acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
+
+ if (resumed_bm_rld != saved_bm_rld)
+ acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
+}
int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
{
+ if (acpi_idle_suspend == 1)
+ return 0;
+
+ acpi_idle_bm_rld_save();
acpi_idle_suspend = 1;
return 0;
}
int acpi_processor_resume(struct acpi_device * device)
{
+ if (acpi_idle_suspend == 0)
+ return 0;
+
+ acpi_idle_bm_rld_restore();
acpi_idle_suspend = 0;
return 0;
}