Hi Laurent,
On 23/03/2021 00:12, Laurent Pinchart wrote:
> When the system shuts down or warm reboots, the display may be active,
> with the hardware accessing system memory. Upon reboot, the DDR will not
> be accessible, which may cause issues.
Troublesome indeed.
> Implement the platform_driver .shutdown() operation and shut down the
> display to fix this.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Looking in drm_atomic_helper.c, I saw reference to
drm_atomic_helper_shutdown() also being used at driver unload ... so I
was going to ask about that - until I saw "Shutdown the display on
remove" which is in the next 2 patches of my review queue ;-)
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/rcar-du/rcar_du_drv.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> index bfbff90588cb..43de3d8686e8 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> @@ -561,6 +561,13 @@ static int rcar_du_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static void rcar_du_shutdown(struct platform_device *pdev)
> +{
> + struct rcar_du_device *rcdu = platform_get_drvdata(pdev);
> +
> + drm_atomic_helper_shutdown(&rcdu->ddev);
> +}
> +
> static int rcar_du_probe(struct platform_device *pdev)
> {
> struct rcar_du_device *rcdu;
> @@ -617,6 +624,7 @@ static int rcar_du_probe(struct platform_device *pdev)
> static struct platform_driver rcar_du_platform_driver = {
> .probe = rcar_du_probe,
> .remove = rcar_du_remove,
> + .shutdown = rcar_du_shutdown,
> .driver = {
> .name = "rcar-du",
> .pm = &rcar_du_pm_ops,
>
