msm: acpuclock-krait: Remove use of QSB as a CPU or L2 clock source
QSB's rate is tied to the Apps fabric (or BIMC on 8974), which means
that its rate is unpredictable. When the CPU is running at a low
voltage, if the QSB clock source is selected, it's possible that the
CPU clock rate could increase beyond the safe limit for that voltage.
Instead of selecting QSB for power-collapse and hotplug scenarios,
select an always-on source with a predictable rate.
Change-Id: I7c39d443bf49371358d0a618693a6efe2f26fcc4
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
diff --git a/arch/arm/mach-msm/acpuclock-krait.c b/arch/arm/mach-msm/acpuclock-krait.c
index 1469bee..33396e5 100644
--- a/arch/arm/mach-msm/acpuclock-krait.c
+++ b/arch/arm/mach-msm/acpuclock-krait.c
@@ -41,7 +41,6 @@
#define PRI_SRC_SEL_SEC_SRC 0
#define PRI_SRC_SEL_HFPLL 1
#define PRI_SRC_SEL_HFPLL_DIV2 2
-#define SEC_SRC_SEL_QSB 0
#define SEC_SRC_SEL_L2PLL 1
#define SEC_SRC_SEL_AUX 2
@@ -513,6 +512,11 @@
return rc;
}
+static struct acpuclk_data acpuclk_krait_data = {
+ .set_rate = acpuclk_krait_set_rate,
+ .get_rate = acpuclk_krait_get_rate,
+};
+
/* Initialize a HFPLL at a given rate and enable it. */
static void __init hfpll_init(struct scalable *sc,
const struct core_speed *tgt_s)
@@ -775,7 +779,7 @@
}
acpu_level = find_cur_acpu_level(cpu);
- if (!acpu_level || acpu_level->speed.src == QSB) {
+ if (!acpu_level) {
acpu_level = find_min_acpu_level();
if (!acpu_level) {
ret = -ENODEV;
@@ -863,20 +867,20 @@
static void __init cpufreq_table_init(void) {}
#endif
-#define HOT_UNPLUG_KHZ STBY_KHZ
static int __cpuinit acpuclk_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
static int prev_khz[NR_CPUS];
int rc, cpu = (int)hcpu;
struct scalable *sc = &drv.scalable[cpu];
+ unsigned long hot_unplug_khz = acpuclk_krait_data.power_collapse_khz;
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_DEAD:
prev_khz[cpu] = acpuclk_krait_get_rate(cpu);
/* Fall through. */
case CPU_UP_CANCELED:
- acpuclk_krait_set_rate(cpu, HOT_UNPLUG_KHZ, SETRATE_HOTPLUG);
+ acpuclk_krait_set_rate(cpu, hot_unplug_khz, SETRATE_HOTPLUG);
regulator_set_optimum_mode(sc->vreg[VREG_CORE].reg, 0);
break;
case CPU_UP_PREPARE:
@@ -972,13 +976,6 @@
return tbl_idx;
}
-static struct acpuclk_data acpuclk_krait_data = {
- .set_rate = acpuclk_krait_set_rate,
- .get_rate = acpuclk_krait_get_rate,
- .power_collapse_khz = STBY_KHZ,
- .wait_for_irq_khz = STBY_KHZ,
-};
-
static void __init drv_data_init(struct device *dev,
const struct acpuclk_krait_params *params)
{
@@ -1011,6 +1008,9 @@
GFP_KERNEL);
BUG_ON(!drv.acpu_freq_tbl);
drv.boost_uv = params->pvs_tables[tbl_idx].boost_uv;
+
+ acpuclk_krait_data.power_collapse_khz = params->stby_khz;
+ acpuclk_krait_data.wait_for_irq_khz = params->stby_khz;
}
static void __init hw_init(void)
@@ -1033,9 +1033,10 @@
BUG_ON(rc);
l2_level = find_cur_l2_level();
- if (!l2_level || l2_level->speed.src == QSB) {
+ if (!l2_level) {
l2_level = drv.l2_freq_tbl;
- dev_dbg(drv.dev, "L2 is running at an unknown rate. Defaulting to QSB.\n");
+ dev_dbg(drv.dev, "L2 is running at an unknown rate. Defaulting to %lu KHz.\n",
+ l2_level->speed.khz);
} else {
dev_dbg(drv.dev, "L2 is running at %lu KHz\n",
l2_level->speed.khz);