1 files changed, 48 insertions, 17 deletions

diff --git a/drivers/mfd/wm831x-core.c b/drivers/mfd/wm831x-core.c
index f2ab025ad97..da00ca9e0c7 100644
--- a/drivers/mfd/wm831x-core.c
+++ b/drivers/mfd/wm831x-core.c
@@ -322,7 +322,11 @@ EXPORT_SYMBOL_GPL(wm831x_set_bits);
  */
 int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
 {
-	int ret, src;
+	int ret, src, irq_masked, timeout;
+
+	/* Are we using the interrupt? */
+	irq_masked = wm831x_reg_read(wm831x, WM831X_INTERRUPT_STATUS_1_MASK);
+	irq_masked &= WM831X_AUXADC_DATA_EINT;
 
 	mutex_lock(&wm831x->auxadc_lock);
 
@@ -342,6 +346,9 @@ int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
 		goto out;
 	}
 
+	/* Clear any notification from a very late arriving interrupt */
+	try_wait_for_completion(&wm831x->auxadc_done);
+
 	ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
 			      WM831X_AUX_CVT_ENA, WM831X_AUX_CVT_ENA);
 	if (ret < 0) {
@@ -349,22 +356,46 @@ int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
 		goto disable;
 	}
 
-	/* If an interrupt arrived late clean up after it */
-	try_wait_for_completion(&wm831x->auxadc_done);
-
-	/* Ignore the result to allow us to soldier on without IRQ hookup */
-	wait_for_completion_timeout(&wm831x->auxadc_done, msecs_to_jiffies(5));
-
-	ret = wm831x_reg_read(wm831x, WM831X_AUXADC_CONTROL);
-	if (ret < 0) {
-		dev_err(wm831x->dev, "AUXADC status read failed: %d\n", ret);
-		goto disable;
-	}
-
-	if (ret & WM831X_AUX_CVT_ENA) {
-		dev_err(wm831x->dev, "Timed out reading AUXADC\n");
-		ret = -EBUSY;
-		goto disable;
+	if (irq_masked) {
+		/* If we're not using interrupts then poll the
+		 * interrupt status register */
+		timeout = 5;
+		while (timeout) {
+			msleep(1);
+
+			ret = wm831x_reg_read(wm831x,
+					      WM831X_INTERRUPT_STATUS_1);
+			if (ret < 0) {
+				dev_err(wm831x->dev,
+					"ISR 1 read failed: %d\n", ret);
+				goto disable;
+			}
+
+			/* Did it complete? */
+			if (ret & WM831X_AUXADC_DATA_EINT) {
+				wm831x_reg_write(wm831x,
+						 WM831X_INTERRUPT_STATUS_1,
+						 WM831X_AUXADC_DATA_EINT);
+				break;
+			} else {
+				dev_err(wm831x->dev,
+					"AUXADC conversion timeout\n");
+				ret = -EBUSY;
+				goto disable;
+			}
+		}
+	} else {
+		/* If we are using interrupts then wait for the
+		 * interrupt to complete.  Use an extremely long
+		 * timeout to handle situations with heavy load where
+		 * the notification of the interrupt may be delayed by
+		 * threaded IRQ handling. */
+		if (!wait_for_completion_timeout(&wm831x->auxadc_done,
+						 msecs_to_jiffies(500))) {
+			dev_err(wm831x->dev, "Timed out waiting for AUXADC\n");
+			ret = -EBUSY;
+			goto disable;
+		}
 	}
 
 	ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);