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From:   Werner Sembach <wse@tuxedocomputers.com>
To:     rafael@kernel.org, lenb@kernel.org, linux-acpi@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] ACPI: video: Force backlight native for some TongFang devices
Date:   Thu,  7 Jul 2022 20:09:52 +0200
Message-Id: <20220707180953.605246-1-wse@tuxedocomputers.com>
MIME-Version: 1.0
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The TongFang PF5PU1G, PF4NU1F, PF5NU1G, and PF5LUXG/TUXEDO BA15 Gen10,
Pulse 14/15 Gen1, and Pulse 15 Gen2 have the same problem as the Clevo
NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2:
They have a working native and video interface. However the default
detection mechanism first registers the video interface before
unregistering it again and switching to the native interface during boot.
This results in a dangling SBIOS request for backlight change for some
reason, causing the backlight to switch to ~2% once per boot on the first
power cord connect or disconnect event. Setting the native interface
explicitly circumvents this buggy behaviour by avoiding the unregistering
process.

Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
Cc: stable@vger.kernel.org
---
 drivers/acpi/video_detect.c | 51 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index becc198e4c22..cdde2e069d63 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -490,7 +490,56 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
 		DMI_MATCH(DMI_BOARD_NAME, "NL5xNU"),
 		},
 	},
-
+	/*
+	 * The TongFang PF5PU1G, PF4NU1F, PF5NU1G, and PF5LUXG/TUXEDO BA15 Gen10,
+	 * Pulse 14/15 Gen1, and Pulse 15 Gen2 have the same problem as the Clevo
+	 * NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2. See the description
+	 * above.
+	 */
+	{
+	.callback = video_detect_force_native,
+	.ident = "TongFang PF5PU1G",
+	.matches = {
+		DMI_MATCH(DMI_BOARD_NAME, "PF5PU1G"),
+		},
+	},
+	{
+	.callback = video_detect_force_native,
+	.ident = "TongFang PF4NU1F",
+	.matches = {
+		DMI_MATCH(DMI_BOARD_NAME, "PF4NU1F"),
+		},
+	},
+	{
+	.callback = video_detect_force_native,
+	.ident = "TongFang PF4NU1F",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
+		DMI_MATCH(DMI_BOARD_NAME, "PULSE1401"),
+		},
+	},
+	{
+	.callback = video_detect_force_native,
+	.ident = "TongFang PF5NU1G",
+	.matches = {
+		DMI_MATCH(DMI_BOARD_NAME, "PF5NU1G"),
+		},
+	},
+	{
+	.callback = video_detect_force_native,
+	.ident = "TongFang PF5NU1G",
+	.matches = {
+		DMI_MATCH(DMI_SYS_VENDOR, "TUXEDO"),
+		DMI_MATCH(DMI_BOARD_NAME, "PULSE1501"),
+		},
+	},
+	{
+	.callback = video_detect_force_native,
+	.ident = "TongFang PF5LUXG",
+	.matches = {
+		DMI_MATCH(DMI_BOARD_NAME, "PF5LUXG"),
+		},
+	},
 	/*
 	 * Desktops which falsely report a backlight and which our heuristics
 	 * for this do not catch.
-- 
2.34.1