Re: [PATCH v3 0/5] Add SW_TABLET_MODE support for AMD SFH convertibles

On 8/14/2026 6:14 PM, Jiri Kosina wrote:

On Mon, 3 Aug 2026, Basavaraj Natikar wrote:

quoted

Add SW_TABLET_MODE support for AMD convertibles whose operating mode
(laptop or tablet) is reported by the Sensor Fusion Hub.

Patches 1 and 2 are preparation: the first tracks the MP2 version
explicitly and the second serializes access to the shared emp2 pointer.
The third adds a way to read the operating mode. The fourth registers an
auxiliary device when the sensor is present, and the fifth is a small
input driver that binds to it and reports the posture to userspace.
Keeping the input handling in its own driver avoids pulling input/evdev
into the sensor transport driver.

Changes in v3:
- Destroy the tablet-mode auxiliary device before the hardware teardown
   in .remove(), instead of from a devres action that runs afterwards,
   closing a use-after-teardown window (Sashiko review).
- Move the Makefile entry to its correct alphabetical position
   (Dmitry Torokhov).

Changes in v2 (address the Sashiko review of v1):
- Read the operating-mode register only on confirmed MP2 v2, by tracking
   the MP2 version explicitly. On v1.0 that register overlaps the 64-bit
   DMA address programmed through C2P, so the earlier unconditional read
   could return DMA bits instead of the operating mode.
- Serialize the shared emp2 pointer and all exported readers under a
   mutex, so a concurrent unbind can no longer free the device while a
   reader is still dereferencing it.
- Publish emp2 only after initialization has populated the client data,
   and clear it early on the MP2 v2 remove path instead of from a
   prematurely registered devres action; this removes both the
   publish-before-init data race and the unconditional global clear on a
   probe failure.
- Destroy the tablet-mode auxiliary device and release its id on removal,
   and allocate the id dynamically so multiple instances cannot collide.
- Report the initial tablet-mode state before registering the input
   device, so userspace never observes a stale default posture.
- Rename the error variable from 'rc' to 'error' to follow the
   input-subsystem convention.

v2: https://lore.kernel.org/all/20260803145801.3801862-1-Basavaraj.Natikar@amd.com/ (local)
v1: https://lore.kernel.org/all/20260721174422.3109166-1-Basavaraj.Natikar@amd.com/ (local)

Now queued in hid.git#for-7.3/amd-sfh, sorry for the delay. Myself and
Benjamin have been on a few weeks on leave in parallel, and then didn't
really help with the throughput ... still recovering :)

Thanks a lot, Jiri, and no worries at all about the delay.
I really appreciate you and Benjamin taking the time to
review it. Hope you're both back to full strength soon.

Thanks again for queuing it up.

Thanks,
-- 
Basavaraj