From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- include/acpi/video.h | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 include/acpi/video.h (limited to 'include/acpi/video.h') diff --git a/include/acpi/video.h b/include/acpi/video.h new file mode 100644 index 000000000..044c46313 --- /dev/null +++ b/include/acpi/video.h @@ -0,0 +1,121 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ACPI_VIDEO_H +#define __ACPI_VIDEO_H + +#include /* for ENODEV */ +#include /* for bool */ + +struct acpi_video_brightness_flags { + u8 _BCL_no_ac_battery_levels:1; /* no AC/Battery levels in _BCL */ + u8 _BCL_reversed:1; /* _BCL package is in a reversed order */ + u8 _BQC_use_index:1; /* _BQC returns an index value */ +}; + +struct acpi_video_device_brightness { + int curr; + int count; + int *levels; + struct acpi_video_brightness_flags flags; +}; + +struct acpi_device; + +#define ACPI_VIDEO_CLASS "video" + +#define ACPI_VIDEO_DISPLAY_CRT 1 +#define ACPI_VIDEO_DISPLAY_TV 2 +#define ACPI_VIDEO_DISPLAY_DVI 3 +#define ACPI_VIDEO_DISPLAY_LCD 4 + +#define ACPI_VIDEO_DISPLAY_LEGACY_MONITOR 0x0100 +#define ACPI_VIDEO_DISPLAY_LEGACY_PANEL 0x0110 +#define ACPI_VIDEO_DISPLAY_LEGACY_TV 0x0200 + +#define ACPI_VIDEO_NOTIFY_SWITCH 0x80 +#define ACPI_VIDEO_NOTIFY_PROBE 0x81 +#define ACPI_VIDEO_NOTIFY_CYCLE 0x82 +#define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT 0x83 +#define ACPI_VIDEO_NOTIFY_PREV_OUTPUT 0x84 +#define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS 0x85 +#define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS 0x86 +#define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS 0x87 +#define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS 0x88 +#define ACPI_VIDEO_NOTIFY_DISPLAY_OFF 0x89 + +enum acpi_backlight_type { + acpi_backlight_undef = -1, + acpi_backlight_none = 0, + acpi_backlight_video, + acpi_backlight_vendor, + acpi_backlight_native, + acpi_backlight_nvidia_wmi_ec, + acpi_backlight_apple_gmux, + acpi_backlight_dell_uart, +}; + +#if IS_ENABLED(CONFIG_ACPI_VIDEO) +extern int acpi_video_register(void); +extern void acpi_video_unregister(void); +extern void acpi_video_register_backlight(void); +extern int acpi_video_get_edid(struct acpi_device *device, int type, + int device_id, void **edid); +/* + * Note: The value returned by acpi_video_handles_brightness_key_presses() + * may change over time and should not be cached. + */ +extern bool acpi_video_handles_brightness_key_presses(void); +extern int acpi_video_get_levels(struct acpi_device *device, + struct acpi_video_device_brightness **dev_br, + int *pmax_level); + +extern enum acpi_backlight_type __acpi_video_get_backlight_type(bool native, + bool *auto_detect); + +static inline enum acpi_backlight_type acpi_video_get_backlight_type(void) +{ + return __acpi_video_get_backlight_type(false, NULL); +} + +/* + * This function MUST only be called by GPU drivers to check if the driver + * should register a backlight class device. This function not only checks + * if a GPU native backlight device should be registered it *also* tells + * the ACPI video-detect code that native GPU backlight control is available. + * Therefor calling this from any place other then the GPU driver is wrong! + * To check if GPU native backlight control is used in other places instead use: + * if (acpi_video_get_backlight_type() == acpi_backlight_native) { ... } + */ +static inline bool acpi_video_backlight_use_native(void) +{ + return __acpi_video_get_backlight_type(true, NULL) == acpi_backlight_native; +} +#else +static inline int acpi_video_register(void) { return -ENODEV; } +static inline void acpi_video_unregister(void) { return; } +static inline void acpi_video_register_backlight(void) { return; } +static inline int acpi_video_get_edid(struct acpi_device *device, int type, + int device_id, void **edid) +{ + return -ENODEV; +} +static inline enum acpi_backlight_type acpi_video_get_backlight_type(void) +{ + return acpi_backlight_vendor; +} +static inline bool acpi_video_backlight_use_native(void) +{ + return true; +} +static inline bool acpi_video_handles_brightness_key_presses(void) +{ + return false; +} +static inline int acpi_video_get_levels(struct acpi_device *device, + struct acpi_video_device_brightness **dev_br, + int *pmax_level) +{ + return -ENODEV; +} +#endif + +#endif -- cgit v1.3.1