x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

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 <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 75 insertions, 0 deletions

diff --git a/drivers/leds/TODO b/drivers/leds/TODO
new file mode 100644
index 000000000..bfa60fa1d
--- /dev/null
+++ b/drivers/leds/TODO
@@ -0,0 +1,75 @@
+-*- org -*-
+
+* On/off LEDs should have max_brightness of 1
+* Get rid of enum led_brightness
+
+It is really an integer, as maximum is configurable. Get rid of it, or
+make it into typedef or something.
+
+* Review atomicity requirements in LED subsystem
+
+Calls that may and that may not block are mixed in same structure, and
+semantics is sometimes non-intuitive. (For example blink callback may
+not sleep.) Review the requirements for any bugs and document them
+clearly.
+
+* LED names are still a mess
+
+No two LEDs have same name, so the names are probably unusable for the
+userland. Nudge authors into creating common LED names for common
+functionality.
+
+? Perhaps check for known LED names during boot, and warn if there are
+LEDs not on the list?
+
+* Split drivers into subdirectories
+
+The number of drivers is getting big, and driver for on/off LED on a
+i/o port is really quite different from camera flash LED, which is
+really different from driver for RGB color LED that can run its own
+microcode. Split the drivers somehow.
+
+* Figure out what to do with RGB leds
+
+Multicolor is a bit too abstract. Yes, we can have
+Green-Magenta-Ultraviolet LED, but so far all the LEDs we support are
+RGB, and not even RGB-White or RGB-Yellow variants emerged.
+
+Multicolor is not a good fit for RGB LED. It does not really know
+about LED color.  In particular, there's no way to make LED "white".
+
+Userspace is interested in knowing "this LED can produce arbitrary
+color", which not all multicolor LEDs can.
+
+	Proposal: let's add "rgb" to led_colors in drivers/leds/led-core.c,
+	add corresponding device tree defines, and use that, instead of
+	multicolor for RGB LEDs.
+
+	We really need to do that now; "white" stuff can wait.
+
+RGB LEDs are quite common, and it would be good to be able to turn LED
+white and to turn it into any arbitrary color. It is essential that
+userspace is able to set arbitrary colors, and it might be good to
+have that ability from kernel, too... to allow full-color triggers.
+
+* Command line utility to manipulate the LEDs?
+
+/sys interface is not really suitable to use by hand, should we have
+an utility to perform LED control?
+
+In particular, LED names are still a mess (see above) and utility
+could help there by presenting both old and new names while we clean
+them up.
+
+In future, I'd like utility to accept both old and new names while we
+clean them up.
+
+It would be also nice to have useful listing mode -- name, type,
+current brightness/trigger...
+
+In future, it would be good to be able to set rgb led to particular
+color.
+
+And probably user-friendly interface to access LEDs for particular
+ethernet interface would be nice.
+