linux-kernel - [PATCH 4.9 25/74] Revert "pinctrl: intel: Initialize GPIO properly when used through irqchip"

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Message-Id: <20180427135710.947021572@linuxfoundation.org>
Date:   Fri, 27 Apr 2018 15:58:15 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Daniel Drake <drake@...lessm.com>,
        Chris Chiu <chiu@...lessm.com>,
        Linus Walleij <linus.walleij@...aro.org>
Subject: [PATCH 4.9 25/74] Revert "pinctrl: intel: Initialize GPIO properly when used through irqchip"

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

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

From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

This reverts commit f5a26acf0162477af6ee4c11b4fb9cffe5d3e257

Mike writes:
	It seems that commit f5a26acf0162 ("pinctrl: intel: Initialize GPIO
	properly when used through irqchip") can cause problems on some Skylake
	systems with Sunrisepoint PCH-H. Namely on certain systems it may turn
	the backlight PWM pin from native mode to GPIO which makes the screen
	blank during boot.

	There is more information here:

	  https://bugzilla.redhat.com/show_bug.cgi?id=1543769

	The actual reason is that GPIO numbering used in BIOS is using "Windows"
	numbers meaning that they don't match the hardware 1:1 and because of
	this a wrong pin (backlight PWM) is picked and switched to GPIO mode.

	There is a proper fix for this but since it has quite many dependencies
	on commits that cannot be considered stable material, I suggest we
	revert commit f5a26acf0162 from stable trees 4.9, 4.14 and 4.15 to
	prevent the backlight issue.

Reported-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
Fixes: f5a26acf0162 ("pinctrl: intel: Initialize GPIO properly when used through irqchip")
Cc: Daniel Drake <drake@...lessm.com>
Cc: Chris Chiu <chiu@...lessm.com>
Cc: Linus Walleij <linus.walleij@...aro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/pinctrl/intel/pinctrl-intel.c |   23 ++++++++---------------
 1 file changed, 8 insertions(+), 15 deletions(-)

--- a/drivers/pinctrl/intel/pinctrl-intel.c
+++ b/drivers/pinctrl/intel/pinctrl-intel.c
@@ -368,18 +368,6 @@ static void __intel_gpio_set_direction(v
 	writel(value, padcfg0);
 }
 
-static void intel_gpio_set_gpio_mode(void __iomem *padcfg0)
-{
-	u32 value;
-
-	/* Put the pad into GPIO mode */
-	value = readl(padcfg0) & ~PADCFG0_PMODE_MASK;
-	/* Disable SCI/SMI/NMI generation */
-	value &= ~(PADCFG0_GPIROUTIOXAPIC | PADCFG0_GPIROUTSCI);
-	value &= ~(PADCFG0_GPIROUTSMI | PADCFG0_GPIROUTNMI);
-	writel(value, padcfg0);
-}
-
 static int intel_gpio_request_enable(struct pinctrl_dev *pctldev,
 				     struct pinctrl_gpio_range *range,
 				     unsigned pin)
@@ -387,6 +375,7 @@ static int intel_gpio_request_enable(str
 	struct intel_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
 	void __iomem *padcfg0;
 	unsigned long flags;
+	u32 value;
 
 	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
@@ -396,7 +385,13 @@ static int intel_gpio_request_enable(str
 	}
 
 	padcfg0 = intel_get_padcfg(pctrl, pin, PADCFG0);
-	intel_gpio_set_gpio_mode(padcfg0);
+	/* Put the pad into GPIO mode */
+	value = readl(padcfg0) & ~PADCFG0_PMODE_MASK;
+	/* Disable SCI/SMI/NMI generation */
+	value &= ~(PADCFG0_GPIROUTIOXAPIC | PADCFG0_GPIROUTSCI);
+	value &= ~(PADCFG0_GPIROUTSMI | PADCFG0_GPIROUTNMI);
+	writel(value, padcfg0);
+
 	/* Disable TX buffer and enable RX (this will be input) */
 	__intel_gpio_set_direction(padcfg0, true);
 
@@ -775,8 +770,6 @@ static int intel_gpio_irq_type(struct ir
 
 	raw_spin_lock_irqsave(&pctrl->lock, flags);
 
-	intel_gpio_set_gpio_mode(reg);
-
 	value = readl(reg);
 
 	value &= ~(PADCFG0_RXEVCFG_MASK | PADCFG0_RXINV);