4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx> Fixes: f5a26acf0162 ("pinctrl: intel: Initialize GPIO properly when used through irqchip") Cc: Daniel Drake <drake@xxxxxxxxxxxx> Cc: Chris Chiu <chiu@xxxxxxxxxxxx> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -425,18 +425,6 @@ 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) @@ -444,6 +432,7 @@ 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); @@ -453,7 +442,13 @@ 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); @@ -973,8 +968,6 @@ 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);