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authorJyri Sarha <jsarha@ti.com>2018-04-26 11:07:00 +0300
committerThierry Reding <treding@nvidia.com>2018-05-18 12:22:06 +0300
commit0c08754b59da5557532d946599854e6df28edc22 (patch)
treef0ffc11a747bc9d185ec6d62bf8a0ec288cc1e49 /drivers/gpu/drm/drm_panel.c
parent38992c57c9c8425dc9cb75efe6f9b9255ea627a0 (diff)
downloadlinux-0c08754b59da5557532d946599854e6df28edc22.tar.xz
drm/panel: Add device_link from panel device to DRM device
Add device_link from panel device (supplier) to DRM device (consumer) when drm_panel_attach() is called. This patch should protect the master DRM driver if an attached panel driver unbinds while it is in use. The device_link should make sure the DRM device is unbound before the panel driver becomes unavailable. The device_link is removed when drm_panel_detach() is called. The drm_panel_detach() should be called by the consumer DRM driver, not the panel driver, otherwise both drivers are racing to delete the same link. Signed-off-by: Jyri Sarha <jsarha@ti.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Thierry Reding <treding@nvidia.com> Link: https://patchwork.freedesktop.org/patch/msgid/b53584fd988d045c13de22d81825395b0ae0aad7.1524727888.git.jsarha@ti.com
Diffstat (limited to 'drivers/gpu/drm/drm_panel.c')
-rw-r--r--drivers/gpu/drm/drm_panel.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index 71e407574276..965530a6f4cd 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -24,6 +24,7 @@
#include <linux/err.h>
#include <linux/module.h>
+#include <drm/drm_device.h>
#include <drm/drm_crtc.h>
#include <drm/drm_panel.h>
@@ -104,6 +105,13 @@ int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector)
if (panel->connector)
return -EBUSY;
+ panel->link = device_link_add(connector->dev->dev, panel->dev, 0);
+ if (!panel->link) {
+ dev_err(panel->dev, "failed to link panel to %s\n",
+ dev_name(connector->dev->dev));
+ return -EINVAL;
+ }
+
panel->connector = connector;
panel->drm = connector->dev;
@@ -125,6 +133,8 @@ EXPORT_SYMBOL(drm_panel_attach);
*/
int drm_panel_detach(struct drm_panel *panel)
{
+ device_link_del(panel->link);
+
panel->connector = NULL;
panel->drm = NULL;