drm/panel: Make of_drm_find_panel() return an ERR_PTR() instead of NULL
Right now, the DRM panel logic returns NULL when a panel pointing to
the passed OF node is not present in the list of registered panels.
Most drivers interpret this NULL value as -EPROBE_DEFER, but we are
about to modify the semantic of of_drm_find_panel() and let the
framework return -ENODEV when the device node we're pointing to has
a status property that is not equal to "okay" or "ok".
Let's first patch the of_drm_find_panel() implementation to return
ERR_PTR(-EPROBE_DEFER) instead of NULL and patch all callers to replace
the '!panel' check by an 'IS_ERR(panel)' one.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180509130042.9435-2-boris.brezillon@bootlin.com
diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c
index 87c5d89..ad88ec2 100644
--- a/drivers/gpu/drm/tegra/dsi.c
+++ b/drivers/gpu/drm/tegra/dsi.c
@@ -1411,6 +1411,9 @@
struct tegra_output *output = &dsi->output;
output->panel = of_drm_find_panel(device->dev.of_node);
+ if (IS_ERR(output->panel))
+ output->panel = NULL;
+
if (output->panel && output->connector.dev) {
drm_panel_attach(output->panel, &output->connector);
drm_helper_hpd_irq_event(output->connector.dev);
diff --git a/drivers/gpu/drm/tegra/output.c b/drivers/gpu/drm/tegra/output.c
index ffe34bd..0c09365 100644
--- a/drivers/gpu/drm/tegra/output.c
+++ b/drivers/gpu/drm/tegra/output.c
@@ -110,8 +110,8 @@
panel = of_parse_phandle(output->of_node, "nvidia,panel", 0);
if (panel) {
output->panel = of_drm_find_panel(panel);
- if (!output->panel)
- return -EPROBE_DEFER;
+ if (IS_ERR(output->panel))
+ return PTR_ERR(output->panel);
of_node_put(panel);
}