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 --- Documentation/ABI/testing/sysfs-class-extcon | 101 +++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-extcon (limited to 'Documentation/ABI/testing/sysfs-class-extcon') diff --git a/Documentation/ABI/testing/sysfs-class-extcon b/Documentation/ABI/testing/sysfs-class-extcon new file mode 100644 index 000000000..f8e705375 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-extcon @@ -0,0 +1,101 @@ +What: /sys/class/extcon/.../ +Date: February 2012 +Contact: MyungJoo Ham +Description: + Provide a place in sysfs for the extcon objects. + This allows accessing extcon specific variables. + The name of extcon object denoted as ... is the name given + with extcon_dev_register. + + One extcon device denotes a single external connector + port. An external connector may have multiple cables + attached simultaneously. Many of docks, cradles, and + accessory cables have such capability. For example, + the 30-pin port of Nuri board (/arch/arm/mach-exynos) + may have both HDMI and Charger attached, or analog audio, + video, and USB cables attached simultaneously. + + If there are cables mutually exclusive with each other, + such binary relations may be expressed with extcon_dev's + mutually_exclusive array. + +What: /sys/class/extcon/.../name +Date: February 2012 +Contact: MyungJoo Ham +Description: + The /sys/class/extcon/.../name shows the name of the extcon + object. If the extcon object has an optional callback + "show_name" defined, the callback will provide the name with + this sysfs node. + +What: /sys/class/extcon/.../state +Date: February 2012 +Contact: MyungJoo Ham +Description: + The /sys/class/extcon/.../state shows and stores the cable + attach/detach information of the corresponding extcon object. + If the extcon object has an optional callback "show_state" + defined, the showing function is overridden with the optional + callback. + + If the default callback for showing function is used, the + format is like this:: + + # cat state + USB_OTG=1 + HDMI=0 + TA=1 + EAR_JACK=0 + # + + In this example, the extcon device has USB_OTG and TA + cables attached and HDMI and EAR_JACK cables detached. + + In order to update the state of an extcon device, enter a hex + state number starting with 0x:: + + # echo 0xHEX > state + + This updates the whole state of the extcon device. + Inputs of all the methods are required to meet the + mutually_exclusive conditions if they exist. + + It is recommended to use this "global" state interface if + you need to set the value atomically. The later state + interface associated with each cable cannot update + multiple cable states of an extcon device simultaneously. + +What: /sys/class/extcon/.../cable.X/name +Date: February 2012 +Contact: MyungJoo Ham +Description: + The /sys/class/extcon/.../cable.X/name shows the name of cable + "X" (integer between 0 and 31) of an extcon device. + +What: /sys/class/extcon/.../cable.X/state +Date: February 2012 +Contact: MyungJoo Ham +Description: + The /sys/class/extcon/.../cable.X/state shows and stores the + state of cable "X" (integer between 0 and 31) of an extcon + device. The state value is either 0 (detached) or 1 + (attached). + +What: /sys/class/extcon/.../mutually_exclusive/... +Date: December 2011 +Contact: MyungJoo Ham +Description: + Shows the relations of mutually exclusiveness. For example, + if the mutually_exclusive array of extcon device is + {0x3, 0x5, 0xC, 0x0}, then the output is:: + + # ls mutually_exclusive/ + 0x3 + 0x5 + 0xc + # + + Note that mutually_exclusive is a sub-directory of the extcon + device and the file names under the mutually_exclusive + directory show the mutually-exclusive sets, not the contents + of the files. -- cgit v1.3.1