Commit 39c17ae6 authored by Lyude Paul's avatar Lyude Paul
Browse files

drm/tegra: Don't register DP AUX channels before connectors 



As pointed out by the documentation for drm_dp_aux_register(),
drm_dp_aux_init() should be used in situations where the AUX channel for a
display driver can potentially be registered before it's respective DRM
driver. This is the case with Tegra, since the DP aux channel exists as a
platform device instead of being a grandchild of the DRM device.

Since we're about to add a backpointer to a DP AUX channel's respective DRM
device, let's fix this so that we don't potentially allow userspace to use
the AUX channel before we've associated it with it's DRM connector.

Signed-off-by: default avatarLyude Paul <lyude@redhat.com>
Acked-by: default avatarThierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210326203807.105754-3-lyude@redhat.com
parent 45d96999

drivers/gpu/drm/tegra/dpaux.c

+6 −5
Original line number Diff line number Diff line
@@ -534,9 +534,7 @@ static int tegra_dpaux_probe(struct platform_device *pdev) 
	dpaux->aux.transfer = tegra_dpaux_transfer;

	dpaux->aux.dev = &pdev->dev;



	err = drm_dp_aux_register(&dpaux->aux);

	if (err < 0)

		return err;

	drm_dp_aux_init(&dpaux->aux);



	/*

	 * Assume that by default the DPAUX/I2C pads will be used for HDMI,
@@ -589,8 +587,6 @@ static int tegra_dpaux_remove(struct platform_device *pdev) 
	pm_runtime_put_sync(&pdev->dev);

	pm_runtime_disable(&pdev->dev);



	drm_dp_aux_unregister(&dpaux->aux);



	mutex_lock(&dpaux_lock);

	list_del(&dpaux->list);

	mutex_unlock(&dpaux_lock);
@@ -723,6 +719,10 @@ int drm_dp_aux_attach(struct drm_dp_aux *aux, struct tegra_output *output) 
	unsigned long timeout;

	int err;



	err = drm_dp_aux_register(aux);

	if (err < 0)

		return err;



	output->connector.polled = DRM_CONNECTOR_POLL_HPD;

	dpaux->output = output;
@@ -760,6 +760,7 @@ int drm_dp_aux_detach(struct drm_dp_aux *aux) 
	unsigned long timeout;

	int err;



	drm_dp_aux_unregister(aux);

	disable_irq(dpaux->irq);



	if (dpaux->output->panel) {