Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org,
        "Rafael J . Wysocki" <rjw@rjwysocki.net>,
        "Hans de Goede" <hdegoede@redhat.com>,
        "Thierry Reding" <thierry.reding@gmail.com>
Date:   Sun, 11 Nov 2018 19:49:05 +0000
Message-ID: <lsq.1541965745.509743851@decadent.org.uk>
Subject: [PATCH 3.16 122/366] ACPI / LPSS: Add missing prv_offset setting
 for byt/cht PWM devices
In-Reply-To: <lsq.1541965744.387173642@decadent.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

3.16.61-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Hans de Goede <hdegoede@redhat.com>

commit fdcb613d49321b5bf5d5a1bd0fba8e7c241dcc70 upstream.

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.

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>
[bwh: Backported to 3.16:
 - Drop changes for Braswell
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -150,6 +150,7 @@ static struct lpss_shared_clock pwm_cloc
 
 static struct lpss_device_desc byt_pwm_dev_desc = {
 	.clk_required = true,
+	.prv_offset = 0x800,
 	.save_ctx = true,
 	.shared_clock = &pwm_clock,
 };