msm: cpr-regulator: Improve CPR interrupt handling
disable_irq() is not an efficient call and could cause potential deadlock.
Improve the interrupt handling by removing disable_irq and enable_irq
completely, and instead, checking the state of the interrupt source
(LOOP_EN and BUSY bits) in ISR to bail out immediately if any condition is
not met.
CRs-Fixed: 630182
Change-Id: Ieedadf4f0db4febc41ab85f383af683bdaf34615
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>
Signed-off-by: Ke Liu <keliu@codeaurora.org>
diff --git a/arch/arm/mach-msm/cpr-regulator.c b/arch/arm/mach-msm/cpr-regulator.c
index d952f82..d15da59f 100644
--- a/arch/arm/mach-msm/cpr-regulator.c
+++ b/arch/arm/mach-msm/cpr-regulator.c
@@ -96,6 +96,8 @@
/* RBCPR Result status Register */
#define REG_RBCPR_RESULT_0 0xA0
+#define RBCPR_RESULT0_BUSY_SHIFT 19
+#define RBCPR_RESULT0_BUSY_MASK BIT(RBCPR_RESULT0_BUSY_SHIFT)
#define RBCPR_RESULT0_ERROR_STEPS_SHIFT 2
#define RBCPR_RESULT0_ERROR_STEPS_BITS 4
#define RBCPR_RESULT0_ERROR_STEPS_MASK ((1<<RBCPR_RESULT0_ERROR_STEPS_BITS)-1)
@@ -388,6 +390,22 @@
cpr_ctl_modify(cpr_vreg, RBCPR_CTL_LOOP_EN, 0);
}
+static bool cpr_ctl_is_enabled(struct cpr_regulator *cpr_vreg)
+{
+ u32 reg_val;
+
+ reg_val = cpr_read(cpr_vreg, REG_RBCPR_CTL);
+ return reg_val & RBCPR_CTL_LOOP_EN;
+}
+
+static bool cpr_ctl_is_busy(struct cpr_regulator *cpr_vreg)
+{
+ u32 reg_val;
+
+ reg_val = cpr_read(cpr_vreg, REG_RBCPR_RESULT_0);
+ return reg_val & RBCPR_RESULT0_BUSY_MASK;
+}
+
static void cpr_corner_save(struct cpr_regulator *cpr_vreg, int corner)
{
cpr_vreg->save_ctl[corner] = cpr_read(cpr_vreg, REG_RBCPR_CTL);
@@ -732,7 +750,13 @@
cpr_debug_irq("IRQ_STATUS = 0x%02X\n", reg_val);
- if (!cpr_is_allowed(cpr_vreg)) {
+ if (!cpr_ctl_is_enabled(cpr_vreg)) {
+ cpr_debug_irq("CPR is disabled\n");
+ goto _exit;
+ } else if (cpr_ctl_is_busy(cpr_vreg)) {
+ cpr_debug_irq("CPR measurement is not ready\n");
+ goto _exit;
+ } else if (!cpr_is_allowed(cpr_vreg)) {
reg_val = cpr_read(cpr_vreg, REG_RBCPR_CTL);
pr_err("Interrupt broken? RBCPR_CTL = 0x%02X\n", reg_val);
goto _exit;
@@ -897,7 +921,6 @@
mutex_lock(&cpr_vreg->cpr_mutex);
cpr_ctl_disable(cpr_vreg);
- disable_irq(cpr_vreg->cpr_irq);
cpr_irq_clr(cpr_vreg);
@@ -917,7 +940,6 @@
cpr_vreg->is_cpr_suspended = false;
cpr_irq_clr(cpr_vreg);
- enable_irq(cpr_vreg->cpr_irq);
cpr_ctl_enable(cpr_vreg, cpr_vreg->corner);
mutex_unlock(&cpr_vreg->cpr_mutex);