Re: [PATCH] pmdomain: renesas: r8a78000: Fix lockdep false positive

On 26-09-07 16:32:01, Geert Uytterhoeven wrote:

Lockdep reports a possible circular locking dependency when attaching
devices to an MDLC PM domain:

  - During creation of the singleton PM domain:
      A. r8a78000_genpd_always_on_singleton() takes r8a78000_mdlc_lock,
      B. pm_genpd_init() takes gpd_list_lock.

  - During attachment of devices to PM domains:
      A. pm_genpd_add_device() takes gpd_list_lock,
      B. r8a78000_mdlc_attach_dev() takes r8a78000_mdlc_lock.

As the former is done only once, before any devices are attached, such a
AB-BA deadlock cannot really happen.  Fix this false positive by
introducing a separate lock to protect the creation of the singleton
domain.

Fixes: 89e6a71b35703f10 ("pmdomain: renesas: Add R-Car X5H MDLC driver")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Looks OK to me, so:

Reviewed-by: Abel Vesa <redacted>