1 files changed, 48 insertions, 17 deletions

diff --git a/drivers/mfd/wm831x-core.c b/drivers/mfd/wm831x-core.c
index f2ab025ad97a..da00ca9e0c71 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);