FAILED: patch "[PATCH] ACPI / LPSS: Add missing prv_offset setting for byt/cht PWM" failed to apply to 4.9-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From fdcb613d49321b5bf5d5a1bd0fba8e7c241dcc70 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Thu, 26 Apr 2018 14:10:24 +0200
Subject: [PATCH] ACPI / LPSS: Add missing prv_offset setting for byt/cht PWM
 devices

The LPSS PWM device on on Bay Trail and Cherry Trail devices has a set
of private registers at offset 0x800, the current lpss_device_desc for
them already sets the LPSS_SAVE_CTX flag to have these saved/restored
over device-suspend, but the current lpss_device_desc was not setting
the prv_offset field, leading to the regular device registers getting
saved/restored instead.

This is causing the PWM controller to no longer work, resulting in a black
screen,  after a suspend/resume on systems where the firmware clears the
APB clock and reset bits at offset 0x804.

This commit fixes this by properly setting prv_offset to 0x800 for
the PWM devices.

Cc: stable@vger.kernel.org
Fixes: e1c748179754 ("ACPI / LPSS: Add Intel BayTrail ACPI mode PWM")
Fixes: 1bfbd8eb8a7f ("ACPI / LPSS: Add ACPI IDs for Intel Braswell")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rafael J . Wysocki <rjw@rjwysocki.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 2bcffec8dbf0..c4ba9164e582 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -229,11 +229,13 @@ static const struct lpss_device_desc lpt_sdio_dev_desc = {
 
 static const struct lpss_device_desc byt_pwm_dev_desc = {
 	.flags = LPSS_SAVE_CTX,
+	.prv_offset = 0x800,
 	.setup = byt_pwm_setup,
 };
 
 static const struct lpss_device_desc bsw_pwm_dev_desc = {
 	.flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
+	.prv_offset = 0x800,
 	.setup = bsw_pwm_setup,
 };