[PATCH 4.9 13/21] pinctrl: cherryview: Mask all interrupts on Intel_Strago based systems

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Mika Westerberg <mika.westerberg@linux.intel.com>

commit d2b3c353595a855794f8b9df5b5bdbe8deb0c413 upstream.

Guenter Roeck reported an interrupt storm on a prototype system which is
based on Cyan Chromebook. The root cause turned out to be a incorrectly
configured pin that triggers spurious interrupts. This will be fixed in
coreboot but currently we need to prevent the interrupt storm from
happening by masking all interrupts (but not GPEs) on those systems.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=197953
Fixes: bcb48cca23ec ("pinctrl: cherryview: Do not mask all interrupts in probe")
Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/pinctrl/intel/pinctrl-cherryview.c |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

--- a/drivers/pinctrl/intel/pinctrl-cherryview.c
+++ b/drivers/pinctrl/intel/pinctrl-cherryview.c
@@ -1594,6 +1594,22 @@ static int chv_gpio_probe(struct chv_pin
 			clear_bit(i, chip->irq_valid_mask);
 	}
 
+	/*
+	 * The same set of machines in chv_no_valid_mask[] have incorrectly
+	 * configured GPIOs that generate spurious interrupts so we use
+	 * this same list to apply another quirk for them.
+	 *
+	 * See also https://bugzilla.kernel.org/show_bug.cgi?id=197953.
+	 */
+	if (!need_valid_mask) {
+		/*
+		 * Mask all interrupts the community is able to generate
+		 * but leave the ones that can only generate GPEs unmasked.
+		 */
+		chv_writel(GENMASK(31, pctrl->community->nirqs),
+			   pctrl->regs + CHV_INTMASK);
+	}
+
 	/* Clear all interrupts */
 	chv_writel(0xffff, pctrl->regs + CHV_INTSTAT);