ACPI: remove BM_RLD access from idle entry path

[pandora-kernel.git] / drivers / acpi / processor_idle.c

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 5f8d746..7eab733 100644 (file)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -41,6 +41,7 @@
 #include <linux/pm_qos_params.h>
 #include <linux/clockchips.h>
 #include <linux/cpuidle.h>
+#include <linux/irqflags.h>
 
 /*
  * Include the apic definitions for x86 to have the APIC timer related defines
@@ -240,26 +241,6 @@ acpi_processor_power_activate(struct acpi_processor *pr,
                old->promotion.count = 0;
        new->demotion.count = 0;
 
-       /* Cleanup from old state. */
-       if (old) {
-               switch (old->type) {
-               case ACPI_STATE_C3:
-                       /* Disable bus master reload */
-                       if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
-                               acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
-                       break;
-               }
-       }
-
-       /* Prepare to use new state. */
-       switch (new->type) {
-       case ACPI_STATE_C3:
-               /* Enable bus master reload */
-               if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
-                       acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
-               break;
-       }
-
        pr->power.state = new;
 
        return;
@@ -374,15 +355,15 @@ static int tsc_halts_in_c(int state)
 {
        switch (boot_cpu_data.x86_vendor) {
        case X86_VENDOR_AMD:
+       case X86_VENDOR_INTEL:
                /*
                 * AMD Fam10h TSC will tick in all
                 * C/P/S0/S1 states when this bit is set.
                 */
-               if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
+               if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
                        return 0;
+
                /*FALL THROUGH*/
-       case X86_VENDOR_INTEL:
-               /* Several cases known where TSC halts in C2 too */
        default:
                return state > ACPI_STATE_C1;
        }
@@ -446,7 +427,7 @@ static void acpi_processor_idle(void)
 
                pr->power.bm_activity <<= diff;
 
-               acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
+               acpi_get_register_unlocked(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
                if (bm_status) {
                        pr->power.bm_activity |= 0x1;
                        acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
@@ -1120,7 +1101,6 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
                                          " for C3 to be enabled on SMP systems\n"));
                        return;
                }
-               acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
        }
 
        /*
@@ -1136,6 +1116,15 @@ static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 #else
        cx->latency_ticks = cx->latency;
 #endif
+       /*
+        * On older chipsets, BM_RLD needs to be set
+        * in order for Bus Master activity to wake the
+        * system from C3.  Newer chipsets handle DMA
+        * during C3 automatically and BM_RLD is a NOP.
+        * In either case, the proper way to
+        * handle BM_RLD is to set it and leave it set.
+        */
+       acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 
        return;
 }
@@ -1382,7 +1371,7 @@ static int acpi_idle_bm_check(void)
 {
        u32 bm_status = 0;
 
-       acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
+       acpi_get_register_unlocked(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
        if (bm_status)
                acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
        /*
@@ -1398,25 +1387,6 @@ static int acpi_idle_bm_check(void)
        return bm_status;
 }
 
-/**
- * acpi_idle_update_bm_rld - updates the BM_RLD bit depending on target state
- * @pr: the processor
- * @target: the new target state
- */
-static inline void acpi_idle_update_bm_rld(struct acpi_processor *pr,
-                                          struct acpi_processor_cx *target)
-{
-       if (pr->flags.bm_rld_set && target->type != ACPI_STATE_C3) {
-               acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
-               pr->flags.bm_rld_set = 0;
-       }
-
-       if (!pr->flags.bm_rld_set && target->type == ACPI_STATE_C3) {
-               acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
-               pr->flags.bm_rld_set = 1;
-       }
-}
-
 /**
  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
  * @cx: cstate data
@@ -1472,9 +1442,6 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
                return 0;
        }
 
-       if (pr->flags.bm_check)
-               acpi_idle_update_bm_rld(pr, cx);
-
        t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
        acpi_idle_do_entry(cx);
        t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
@@ -1526,9 +1493,6 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
         */
        acpi_state_timer_broadcast(pr, cx, 1);
 
-       if (pr->flags.bm_check)
-               acpi_idle_update_bm_rld(pr, cx);
-
        if (cx->type == ACPI_STATE_C3)
                ACPI_FLUSH_CPU_CACHE();
 
@@ -1620,8 +1584,6 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
         */
        acpi_state_timer_broadcast(pr, cx, 1);
 
-       acpi_idle_update_bm_rld(pr, cx);
-
        /*
         * disable bus master
         * bm_check implies we need ARB_DIS