[PATCH v2] drm/rockchip: shutdown drm subsystem on shutdown

[Doug Anderson]

Hi,

On Tue, Apr 2, 2019 at 4:38 AM Heiko Stuebner <heiko at sntech.de> wrote:
>
> From: Vicente Bergas <vicencb at gmail.com>
>
> As explained by Robin Murphy:
> > the IOMMU shutdown disables paging, so if the VOP is still
> > scanning out then that will result in whatever IOVAs it was using now going
> > straight out onto the bus as physical addresses.
>
> We had a more radical approach before in commit
> 7f3ef5dedb14 ("drm/rockchip: Allow driver to be shutdown on reboot/kexec")
> but that resulted in new warnings and oopses on shutdown on rk3399
> chromeos devices.
>
> So second try is resurrecting Vicentes shutdown change which should
> achieve the same result but in a less drastic way.
>
> Fixes: 63238173b2fa ("Revert drm/rockchip: Allow driver to be shutdown on reboot/kexec")
> Cc: Jeffy Chen <jeffy.chen at rock-chips.com>
> Cc: Robin Murphy <robin.murphy at arm.com>
> Cc: Marc Zyngier <marc.zyngier at arm.com>
> Cc: Brian Norris <briannorris at chromium.org>
> Cc: Doug Anderson <dianders at chromium.org>
> Cc: stable at vger.kernel.org
> Suggested-by: JeffyChen <jeffy.chen at rock-chips.com>
> Suggested-by: Robin Murphy <robin.murphy at arm.com>
> Signed-off-by: Vicente Bergas <vicencb at gmail.com>
> [adapted commit message to explain the history]
> Signed-off-by: Heiko Stuebner <heiko at sntech.de>
> ---
>  drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 9 +++++++++
>  1 file changed, 9 insertions(+)

I picked this back to the Chrome OS 4.19 kernel and tried it on
rk3288-veyron-jerry.  Rebooting caused no complaints (I confirmed this
code was running by adding a printk).

I plugged in to an HDMI monitor.  Rebooting caused no complaints.

I then let the display idle off (just in case that mattered).  Again
no complaints.

Thus, in case it's helpful:

Tested-by: Douglas Anderson <dianders at chromium.org>