Re: [PATCH 2/2] drm/rockchip: dw_hdmi: Handle suspend/resume

From: Laurent Pinchart
Date: Thu May 16 2019 - 06:16:54 EST


Hi Douglas,

Thank you for the patch.

On Thu, May 02, 2019 at 03:38:08PM -0700, Douglas Anderson wrote:
> On Rockchip rk3288-based Chromebooks when you do a suspend/resume
> cycle:
>
> 1. You lose the ability to detect an HDMI device being plugged in.
>
> 2. If you're using the i2c bus built in to dw_hdmi then it stops
> working.
>
> Let's call the core dw-hdmi's suspend/resume functions to restore
> things.
>
> NOTE: in downstream Chrome OS (based on kernel 3.14) we used the
> "late/early" versions of suspend/resume because we found that the VOP
> was sometimes resuming before dw_hdmi and then calling into us before
> we were fully resumed. For now I have gone back to the normal
> suspend/resume because I can't reproduce the problems.

Should this be solved with device links if needed ?

> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> ---
>
> drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
> index 4cdc9f86c2e5..deb0e8c30c03 100644
> --- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
> @@ -542,11 +542,31 @@ static int dw_hdmi_rockchip_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static int __maybe_unused dw_hdmi_rockchip_suspend(struct device *dev)
> +{
> + struct rockchip_hdmi *hdmi = dev_get_drvdata(dev);
> +
> + return dw_hdmi_suspend(hdmi->hdmi);
> +}
> +
> +static int __maybe_unused dw_hdmi_rockchip_resume(struct device *dev)
> +{
> + struct rockchip_hdmi *hdmi = dev_get_drvdata(dev);
> +
> + return dw_hdmi_resume(hdmi->hdmi);
> +}
> +
> +const struct dev_pm_ops dw_hdmi_rockchip_pm = {

Missing static keyword ?

Apart from this,

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

> + SET_SYSTEM_SLEEP_PM_OPS(dw_hdmi_rockchip_suspend,
> + dw_hdmi_rockchip_resume)
> +};
> +
> struct platform_driver dw_hdmi_rockchip_pltfm_driver = {
> .probe = dw_hdmi_rockchip_probe,
> .remove = dw_hdmi_rockchip_remove,
> .driver = {
> .name = "dwhdmi-rockchip",
> + .pm = &dw_hdmi_rockchip_pm,
> .of_match_table = dw_hdmi_rockchip_dt_ids,
> },
> };

--
Regards,

Laurent Pinchart