[PATCH v4] pmdomain: imx: gpcv2: Fix the imx8mm gpu hang due to wrong adb400 reset

[Jacky Bai]

Hi Ulf,

> Subject: Re: [PATCH v4] pmdomain: imx: gpcv2: Fix the imx8mm gpu hang due to
> wrong adb400 reset
> 
> On Fri, 6 Feb 2026 at 15:42, Jacky Bai <ping.bai at nxp.com> wrote:
> >
> > On i.MX8MM, the GPUMIX, GPU2D, and GPU3D blocks share a common reset
> > domain. Due to this hardware limitation, powering off/on GPU2D or
> > GPU3D also triggers a reset of the GPUMIX domain, including its ADB400 port.
> > However, the ADB400 interface must always be placed into power‑down
> > mode before being reset.
> >
> > Currently the GPUMIX and GPU2D/3D power domains rely on runtime PM to
> > handle dependency ordering. In some corner cases, the GPUMIX power off
> > sequence is skipped, leaving the ADB400 port active when GPU2D/3D reset.
> > This causes the GPUMIX ADB400 port to be reset while still active,
> > leading to unpredictable bus behavior and GPU hangs.
> >
> > To avoid this, refine the power‑domain control logic so that the
> > GPUMIX
> > ADB400 port is explicitly powered down and powered up as part of the
> > GPU power domain on/off sequence. This ensures proper ordering and
> > prevents incorrect ADB400 reset.
> >
> > Fixes: 055467378bf1 ("driver core: Enable fw_devlink=rpm by default")
> > Cc: stable at vger.kernel.org
> > Suggested-by: Lucas Stach <l.stach at pengutronix.de>
> > Reviewed-by: Lucas Stach <l.stach at pengutronix.de>
> > Tested-by: Philipp Zabel <p.zabel at pengutronix.de>
> > Signed-off-by: Jacky Bai <ping.bai at nxp.com>
> 
> This doesn't apply cleanly on my next branch, can you please rebase and
> re-submit a new version?
> 

For V4, I just added the Fixes and Cc stable kernel tag, no other changes.
As I saw you have already picked the v3 patch, you can ignore this for now.

Thank you for your time. ^_^

BR
> Kind regards
> Uffe
> 
> > ---