linux-kernel - [PATCH 4.4 17/92] ACPI / LPSS: Ignore acpi_device_fix_up

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Message-Id: <20191204174330.518260224@linuxfoundation.org>
Date:   Wed,  4 Dec 2019 18:49:17 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Hans de Goede <hdegoede@...hat.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.4 17/92] ACPI / LPSS: Ignore acpi_device_fix_up_power() return value

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

[ Upstream commit 1a2fa02f7489dc4d746f2a15fb77b3ce1affade8 ]

Ignore acpi_device_fix_up_power() return value. If we return an error
we end up with acpi_default_enumeration() still creating a platform-
device for the device and we end up with the device still being used
but without the special LPSS related handling which is not useful.

Specicifically ignoring the error fixes the touchscreen no longer
working after a suspend/resume on a Prowise PT301 tablet.

This tablet has a broken _PS0 method on the touchscreen's I2C controller,
causing acpi_device_fix_up_power() to fail, causing fallback to standard
platform-dev handling and specifically causing acpi_lpss_save/restore_ctx
to not run.

The I2C controllers _PS0 method does actually turn on the device, but then
does some more nonsense which fails when run during early boot trying to
use I2C opregion handling on another not-yet registered I2C controller.

Signed-off-by: Hans de Goede <hdegoede@...hat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/acpi/acpi_lpss.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 572755e557d6a..e54e6170981b4 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -405,12 +405,7 @@ static int acpi_lpss_create_device(struct acpi_device *adev,
 	 * have _PS0 and _PS3 without _PSC (and no power resources), so
 	 * acpi_bus_init_power() will assume that the BIOS has put them into D0.
 	 */
-	ret = acpi_device_fix_up_power(adev);
-	if (ret) {
-		/* Skip the device, but continue the namespace scan. */
-		ret = 0;
-		goto err_out;
-	}
+	acpi_device_fix_up_power(adev);

 	adev->driver_data = pdata;
 	pdev = acpi_create_platform_device(adev);
-- 
2.20.1