Input: wm831x-ts - Fix races with IRQ management

Commit Message

Mark Brown March 1, 2011, 4:54 p.m. UTC

None

Patch

diff --git a/drivers/input/touchscreen/wm831x-ts.c b/drivers/input/touchscreen/wm831x-ts.c
index 1022f71..3c397c8 100644
--- a/drivers/input/touchscreen/wm831x-ts.c
+++ b/drivers/input/touchscreen/wm831x-ts.c
@@ -68,8 +68,29 @@  struct wm831x_ts {
 	unsigned int pd_irq;
 	bool pressure;
 	bool pen_down;
+	struct work_struct pd_data_work;
+	struct work_struct data_pd_work;
 };
 
+static void wm831x_pd_data(struct work_struct *work)
+{
+	struct wm831x_ts *wm831x_ts =
+		container_of(work, struct wm831x_ts, pd_data_work);
+
+	disable_irq(wm831x_ts->pd_irq);
+	enable_irq(wm831x_ts->data_irq);
+	dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
+}
+
+static void wm831x_data_pd(struct work_struct *work)
+{
+	struct wm831x_ts *wm831x_ts =
+		container_of(work, struct wm831x_ts, data_pd_work);
+
+	enable_irq(wm831x_ts->pd_irq);
+	dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
+}
+
 static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
 {
 	struct wm831x_ts *wm831x_ts = irq_data;
@@ -110,7 +131,10 @@  static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
 	}
 
 	if (!wm831x_ts->pen_down) {
+		/* Switch from data to pen down */
+		dev_dbg(wm831x->dev, "IRQ DATA->PD\n");
 		disable_irq_nosync(wm831x_ts->data_irq);
+		schedule_work(&wm831x_ts->data_pd_work);
 
 		/* Don't need data any more */
 		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
@@ -156,7 +180,10 @@  static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
 			WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
 
 	wm831x_ts->pen_down = true;
-	enable_irq(wm831x_ts->data_irq);
+
+	/* Switch from pen down to data */
+	dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
+	schedule_work(&wm831x_ts->pd_data_work);
 
 	return IRQ_HANDLED;
 }
@@ -185,8 +212,13 @@  static void wm831x_ts_input_close(struct input_dev *idev)
 			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
 			WM831X_TCH_Z_ENA, 0);
 
-	if (wm831x_ts->pen_down)
+	if (wm831x_ts->pen_down) {
+		flush_work_sync(&wm831x_ts->data_pd_work);
 		disable_irq(wm831x_ts->data_irq);
+		enable_irq(wm831x_ts->pd_irq);
+	} else {
+		flush_work_sync(&wm831x_ts->pd_data_work);
+	}
 }
 
 static __devinit int wm831x_ts_probe(struct platform_device *pdev)
@@ -210,6 +242,8 @@  static __devinit int wm831x_ts_probe(struct platform_device *pdev)
 
 	wm831x_ts->wm831x = wm831x;
 	wm831x_ts->input_dev = input_dev;
+	INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data);
+	INIT_WORK(&wm831x_ts->data_pd_work, wm831x_data_pd);
 
 	/*
 	 * If we have a direct IRQ use it, otherwise use the interrupt