From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
patches@lists.linux.dev, Hans de Goede <hdegoede@redhat.com>,
Daniel Dadap <ddadap@nvidia.com>
Subject: [PATCH 6.2 09/11] platform/x86: nvidia-wmi-ec-backlight: Add force module parameter
Date: Thu, 23 Feb 2023 14:05:03 +0100 [thread overview]
Message-ID: <20230223130426.552183775@linuxfoundation.org> (raw)
In-Reply-To: <20230223130426.170746546@linuxfoundation.org>
From: Hans de Goede <hdegoede@redhat.com>
commit 0d9bdd8a550170306c2021b8d6766c5343b870c2 upstream.
On some Lenovo Legion models, the backlight might be driven by either
one of nvidia_wmi_ec_backlight or amdgpu_bl0 at different times.
When the Nvidia WMI EC backlight interface reports the backlight is
controlled by the EC, the current backlight handling only registers
nvidia_wmi_ec_backlight (and registers no other backlight interfaces).
This hides (never registers) the amdgpu_bl0 interface, where as prior
to 6.1.4 users would have both nvidia_wmi_ec_backlight and amdgpu_bl0
and could work around things in userspace.
Add a force module parameter which can be used with acpi_backlight=native
to restore the old behavior as a workound (for now) by passing:
"acpi_backlight=native nvidia-wmi-ec-backlight.force=1"
Fixes: 8d0ca287fd8c ("platform/x86: nvidia-wmi-ec-backlight: Use acpi_video_get_backlight_type()")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217026
Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Daniel Dadap <ddadap@nvidia.com>
Link: https://lore.kernel.org/r/20230217144208.5721-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/platform/x86/nvidia-wmi-ec-backlight.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/platform/x86/nvidia-wmi-ec-backlight.c
+++ b/drivers/platform/x86/nvidia-wmi-ec-backlight.c
@@ -12,6 +12,10 @@
#include <linux/wmi.h>
#include <acpi/video.h>
+static bool force;
+module_param(force, bool, 0444);
+MODULE_PARM_DESC(force, "Force loading (disable acpi_backlight=xxx checks");
+
/**
* wmi_brightness_notify() - helper function for calling WMI-wrapped ACPI method
* @w: Pointer to the struct wmi_device identified by %WMI_BRIGHTNESS_GUID
@@ -91,7 +95,7 @@ static int nvidia_wmi_ec_backlight_probe
int ret;
/* drivers/acpi/video_detect.c also checks that SOURCE == EC */
- if (acpi_video_get_backlight_type() != acpi_backlight_nvidia_wmi_ec)
+ if (!force && acpi_video_get_backlight_type() != acpi_backlight_nvidia_wmi_ec)
return -ENODEV;
/*
next prev parent reply other threads:[~2023-02-23 13:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-23 13:04 [PATCH 6.2 00/11] 6.2.1-rc1 review Greg Kroah-Hartman
2023-02-23 13:04 ` [PATCH 6.2 01/11] uaccess: Add speculation barrier to copy_from_user() Greg Kroah-Hartman
2023-02-23 13:04 ` [PATCH 6.2 02/11] x86/alternatives: Introduce int3_emulate_jcc() Greg Kroah-Hartman
2023-02-23 13:04 ` [PATCH 6.2 03/11] x86/alternatives: Teach text_poke_bp() to patch Jcc.d32 instructions Greg Kroah-Hartman
2023-02-23 13:04 ` [PATCH 6.2 04/11] x86/static_call: Add support for Jcc tail-calls Greg Kroah-Hartman
2023-02-23 13:04 ` [PATCH 6.2 05/11] HID: mcp-2221: prevent UAF in delayed work Greg Kroah-Hartman
2023-02-23 13:05 ` [PATCH 6.2 06/11] wifi: mwifiex: Add missing compatible string for SD8787 Greg Kroah-Hartman
2023-02-23 13:05 ` [PATCH 6.2 07/11] audit: update the mailing list in MAINTAINERS Greg Kroah-Hartman
2023-02-23 13:05 ` [PATCH 6.2 08/11] platform/x86/amd/pmf: Add depends on CONFIG_POWER_SUPPLY Greg Kroah-Hartman
2023-02-23 13:05 ` Greg Kroah-Hartman [this message]
2023-02-23 13:05 ` [PATCH 6.2 10/11] ext4: Fix function prototype mismatch for ext4_feat_ktype Greg Kroah-Hartman
2023-02-23 13:05 ` [PATCH 6.2 11/11] randstruct: disable Clang 15 support Greg Kroah-Hartman
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