drm/udl: Fixed problem with UDL adpater reconnection

Fixed problem with DisplayLink and DisplayLink certified adapers in drm/udl
driver when adapter doesn't want to work if it was initialized with
disconnected DVI cable by enabling drm connectot polling and updating
current connector's state.

Signed-off-by: Robert Tarasov <tutankhamen@chromium.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171013001350.172155-1-tutankhamen@chromium.org

4 files changed, 72 insertions, 26 deletions

diff --git a/drivers/gpu/drm/udl/udl_connector.c b/drivers/gpu/drm/udl/udl_connector.c
index 9f9a49748d17..b4d1464d2d87 100644
--- a/drivers/gpu/drm/udl/udl_connector.c
+++ b/drivers/gpu/drm/udl/udl_connector.c
@@ -14,6 +14,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_crtc_helper.h>
+#include "udl_connector.h"
 #include "udl_drv.h"
 
 /* dummy connector to just get EDID,
@@ -56,28 +57,15 @@ error:
 
 static int udl_get_modes(struct drm_connector *connector)
 {
-        struct udl_device *udl = connector->dev->dev_private;
-        struct edid *edid;
-        int ret;
-
-        edid = (struct edid *)udl_get_edid(udl);
-        if (!edid) {
-                drm_mode_connector_update_edid_property(connector, NULL);
-                return 0;
-        }
-
-        /*
-         * We only read the main block, but if the monitor reports extension
-         * blocks then the drm edid code expects them to be present, so patch
-         * the extension count to 0.
-         */
-        edid->checksum += edid->extensions;
-        edid->extensions = 0;
-
-        drm_mode_connector_update_edid_property(connector, edid);
-        ret = drm_add_edid_modes(connector, edid);
-        kfree(edid);
-        return ret;
+        struct udl_drm_connector *udl_connector =
+                                        container_of(connector,
+                                        struct udl_drm_connector,
+                                        connector);
+
+        drm_mode_connector_update_edid_property(connector, udl_connector->edid);
+        if (udl_connector->edid)
+                return drm_add_edid_modes(connector, udl_connector->edid);
+        return 0;
 }
 
 static int udl_mode_valid(struct drm_connector *connector,
@@ -96,8 +84,33 @@ static int udl_mode_valid(struct drm_connector *connector,
 static enum drm_connector_status
 udl_detect(struct drm_connector *connector, bool force)
 {
-        if (drm_dev_is_unplugged(connector->dev))
+        struct edid *edid;
+        struct udl_device *udl = connector->dev->dev_private;
+        struct udl_drm_connector *udl_connector =
+                                        container_of(connector,
+                                        struct udl_drm_connector,
+                                        connector);
+
+        if (udl_connector->edid != NULL) {
+                kfree(udl_connector->edid);
+                udl_connector->edid = NULL;
+        }
+
+        edid = (struct edid *)udl_get_edid(udl);
+        if (!edid || !memchr_inv(edid, 0, EDID_LENGTH))
                 return connector_status_disconnected;
+
+        udl_connector->edid = edid;
+
+        /*
+         * We only read the main block, but if the monitor reports extension
+         * blocks then the drm edid code expects them to be present, so patch
+         * the extension count to 0.
+         */
+        udl_connector->edid->checksum +=
+                        udl_connector->edid->extensions;
+        udl_connector->edid->extensions = 0;
+
         return connector_status_connected;
 }
 
@@ -117,8 +130,14 @@ static int udl_connector_set_property(struct drm_connector *connector,
 
 static void udl_connector_destroy(struct drm_connector *connector)
 {
+        struct udl_drm_connector *udl_connector =
+                                        container_of(connector,
+                                        struct udl_drm_connector,
+                                        connector);
+
         drm_connector_unregister(connector);
         drm_connector_cleanup(connector);
+        kfree(udl_connector->edid);
         kfree(connector);
 }
 
@@ -138,17 +157,22 @@ static const struct drm_connector_funcs udl_connector_funcs = {
 
 int udl_connector_init(struct drm_device *dev, struct drm_encoder *encoder)
 {
+        struct udl_drm_connector *udl_connector;
         struct drm_connector *connector;
 
-        connector = kzalloc(sizeof(struct drm_connector), GFP_KERNEL);
-        if (!connector)
+        udl_connector = kzalloc(sizeof(struct udl_drm_connector), GFP_KERNEL);
+        if (!udl_connector)
                 return -ENOMEM;
 
-        drm_connector_init(dev, connector, &udl_connector_funcs, DRM_MODE_CONNECTOR_DVII);
+        connector = &udl_connector->connector;
+        drm_connector_init(dev, connector, &udl_connector_funcs,
+                           DRM_MODE_CONNECTOR_DVII);
         drm_connector_helper_add(connector, &udl_connector_helper_funcs);
 
         drm_connector_register(connector);
         drm_mode_connector_attach_encoder(connector, encoder);
+        connector->polled = DRM_CONNECTOR_POLL_HPD |
+                DRM_CONNECTOR_POLL_CONNECT | DRM_CONNECTOR_POLL_DISCONNECT;
 
         return 0;
 }
diff --git a/drivers/gpu/drm/udl/udl_connector.h b/drivers/gpu/drm/udl/udl_connector.h
new file mode 100644
index 000000000000..0fb0db5c4612
--- /dev/null
+++ b/drivers/gpu/drm/udl/udl_connector.h
@@ -0,0 +1,13 @@
+#ifndef __UDL_CONNECTOR_H__
+#define __UDL_CONNECTOR_H__
+
+#include <drm/drm_crtc.h>
+
+struct udl_drm_connector {
+        struct drm_connector connector;
+        /* last udl_detect edid */
+        struct edid *edid;
+};
+
+
+#endif //__UDL_CONNECTOR_H__
diff --git a/drivers/gpu/drm/udl/udl_drv.c b/drivers/gpu/drm/udl/udl_drv.c
index 31421b6b586e..3c45a3064726 100644
--- a/drivers/gpu/drm/udl/udl_drv.c
+++ b/drivers/gpu/drm/udl/udl_drv.c
@@ -14,6 +14,9 @@
 static int udl_usb_suspend(struct usb_interface *interface,
                            pm_message_t message)
 {
+        struct drm_device *dev = usb_get_intfdata(interface);
+
+        drm_kms_helper_poll_disable(dev);
         return 0;
 }
 
@@ -21,6 +24,7 @@ static int udl_usb_resume(struct usb_interface *interface)
 {
         struct drm_device *dev = usb_get_intfdata(interface);
 
+        drm_kms_helper_poll_enable(dev);
         udl_modeset_restore(dev);
         return 0;
 }
diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
index 0328b2c7b210..f1ec4528a73e 100644
--- a/drivers/gpu/drm/udl/udl_main.c
+++ b/drivers/gpu/drm/udl/udl_main.c
@@ -11,6 +11,7 @@
  * more details.
  */
 #include <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
 #include "udl_drv.h"
 
 /* -BULK_SIZE as per usb-skeleton. Can we get full page and avoid overhead? */
@@ -350,6 +351,8 @@ int udl_driver_load(struct drm_device *dev, unsigned long flags)
         if (ret)
                 goto err_fb;
 
+        drm_kms_helper_poll_init(dev);
+
         return 0;
 err_fb:
         udl_fbdev_cleanup(dev);
@@ -371,6 +374,8 @@ void udl_driver_unload(struct drm_device *dev)
 {
         struct udl_device *udl = dev->dev_private;
 
+        drm_kms_helper_poll_fini(dev);
+
         if (udl->urbs.count)
                 udl_free_urb_list(dev);