[PATCH 4.9 39/66] pinctrl: baytrail: Debounce register is one per community

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

commit 1b89970d81bbd52720fc64a3fe9572ee33588363 upstream.

Debounce value is set globally per community. Otherwise user will easily
get a kernel crash when they start using the feature:

BUG: unable to handle kernel paging request at ffffc900003be000
IP: byt_gpio_dbg_show+0xa9/0x430

Make it clear in byt_gpio_reg().

Note that this fix just prevents kernel to crash, but doesn't make any
difference to the existing logic. It means the last caller will win the
trade and debounce value will be configured accordingly. The actual
logic fix needs to be thought about and it's not as important as crash
fix. That's why the latter goes separately and right now.

Fixes: 658b476c742f ("pinctrl: baytrail: Add debounce configuration")
Cc: Cristina Ciocan <cristina.ciocan@xxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Reviewed-by: Jean Delvare <jdelvare@xxxxxxx>
Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/pinctrl/intel/pinctrl-baytrail.c |   13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

--- a/drivers/pinctrl/intel/pinctrl-baytrail.c
+++ b/drivers/pinctrl/intel/pinctrl-baytrail.c
@@ -731,16 +731,23 @@ static void __iomem *byt_gpio_reg(struct
 				  int reg)
 {
 	struct byt_community *comm = byt_get_community(vg, offset);
-	u32 reg_offset = 0;
+	u32 reg_offset;
 
 	if (!comm)
 		return NULL;
 
 	offset -= comm->pin_base;
-	if (reg == BYT_INT_STAT_REG)
+	switch (reg) {
+	case BYT_INT_STAT_REG:
 		reg_offset = (offset / 32) * 4;
-	else
+		break;
+	case BYT_DEBOUNCE_REG:
+		reg_offset = 0;
+		break;
+	default:
 		reg_offset = comm->pad_map[offset] * 16;
+		break;
+	}
 
 	return comm->reg_base + reg_offset + reg;
 }