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-bus-siox | 90 ++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-siox (limited to 'Documentation/ABI/testing/sysfs-bus-siox') diff --git a/Documentation/ABI/testing/sysfs-bus-siox b/Documentation/ABI/testing/sysfs-bus-siox new file mode 100644 index 000000000..50e80238f --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-siox @@ -0,0 +1,90 @@ +What: /sys/bus/siox/devices/siox-X/active +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + On reading represents the current state of the bus. If it + contains a "0" the bus is stopped and connected devices are + expected to not do anything because their watchdog triggered. + When the file contains a "1" the bus is operated and periodically + does a push-pull cycle to write and read data from the + connected devices. + + When writing a "0" or "1" the bus moves to the described state. + +What: /sys/bus/siox/devices/siox-X/device_add +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Write-only file. Write + + + + to add a new device dynamically. is the name that is used to match + to a driver (similar to the platform bus). and define + the length of the input and output shift register in bytes respectively. + + defines the 4 bit device type that is check to identify connection + problems. + + The new device is added to the end of the existing chain. + +What: /sys/bus/siox/devices/siox-X/device_remove +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Write-only file. A single write removes the last device in the siox chain. + +What: /sys/bus/siox/devices/siox-X/poll_interval_ns +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Defines the interval between two poll cycles in nano seconds. + Note this is rounded to jiffies on writing. On reading the current value + is returned. + +What: /sys/bus/siox/devices/siox-X-Y/connected +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value. "0" means the Yth device on siox bus X isn't "connected" i.e. + communication with it is not ensured. "1" signals a working connection. + +What: /sys/bus/siox/devices/siox-X-Y/inbytes +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value reporting the inbytes value provided to siox-X/device_add + +What: /sys/bus/siox/devices/siox-X-Y/status_errors +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Counts the number of time intervals when the read status byte doesn't yield the + expected value. + +What: /sys/bus/siox/devices/siox-X-Y/type +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value reporting the type value provided to siox-X/device_add. + +What: /sys/bus/siox/devices/siox-X-Y/watchdog +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value reporting if the watchdog of the siox device is + active. "0" means the watchdog is not active and the device is expected to + be operational. "1" means the watchdog keeps the device in reset. + +What: /sys/bus/siox/devices/siox-X-Y/watchdog_errors +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value reporting the number to time intervals when the + watchdog was active. + +What: /sys/bus/siox/devices/siox-X-Y/outbytes +KernelVersion: 4.16 +Contact: Thorsten Scherer , Uwe Kleine-König +Description: + Read-only value reporting the outbytes value provided to siox-X/device_add. -- cgit v1.3.1