Hi, On Tue, Apr 2, 2019 at 4:38 AM Heiko Stuebner <heiko@xxxxxxxxx> wrote: > > From: Vicente Bergas <vicencb@xxxxxxxxx> > > 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@xxxxxxxxxxxxxx> > Cc: Robin Murphy <robin.murphy@xxxxxxx> > Cc: Marc Zyngier <marc.zyngier@xxxxxxx> > Cc: Brian Norris <briannorris@xxxxxxxxxxxx> > Cc: Doug Anderson <dianders@xxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Suggested-by: JeffyChen <jeffy.chen@xxxxxxxxxxxxxx> > Suggested-by: Robin Murphy <robin.murphy@xxxxxxx> > Signed-off-by: Vicente Bergas <vicencb@xxxxxxxxx> > [adapted commit message to explain the history] > Signed-off-by: Heiko Stuebner <heiko@xxxxxxxxx> > --- > 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@xxxxxxxxxxxx>