[PATCH v2 2/2] drm/rockchip: dw_hdmi: Handle suspend/resume

From: Douglas Anderson
Date: Thu May 16 2019 - 17:42:55 EST


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.

Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---

Changes in v2:
- Add forgotten static (Laurent)
- No empty stub for suspend (Laurent)

drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
index 4cdc9f86c2e5..beffe44c248a 100644
--- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
@@ -542,11 +542,23 @@ static int dw_hdmi_rockchip_remove(struct platform_device *pdev)
return 0;
}

+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);
+}
+
+static const struct dev_pm_ops dw_hdmi_rockchip_pm = {
+ SET_SYSTEM_SLEEP_PM_OPS(NULL, 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,
},
};
--
2.21.0.1020.gf2820cf01a-goog