drm/udl: Support DRM hot-unplugging

Add drm_dev_enter() and drm_dev_exit() to the various modesetting
functions that interact with the device. After hot-unplugging the
device, these functions will return early. So far, the udl driver
relied on USB interfaces to handle unplugging of the device.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221006095355.23579-10-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c
index a1334f4..34c7fb6 100644 (file)
--- a/drivers/gpu/drm/udl/udl_modeset.c
+++ b/drivers/gpu/drm/udl/udl_modeset.c
@@ -12,6 +12,7 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_damage_helper.h>
+#include <drm/drm_drv.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_atomic_helper.h>
@@ -295,17 +296,24 @@ static const uint64_t udl_primary_plane_fmtmods[] = {
 static void udl_primary_plane_helper_atomic_update(struct drm_plane *plane,
                                                   struct drm_atomic_state *state)
 {
+       struct drm_device *dev = plane->dev;
        struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
        struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
        struct drm_framebuffer *fb = plane_state->fb;
        struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
        struct drm_rect rect;
+       int idx;
+
+       if (!drm_dev_enter(dev, &idx))
+               return;
 
        if (!fb)
                return; /* no framebuffer; plane is disabled */
 
        if (drm_atomic_helper_damage_merged(old_plane_state, plane_state, &rect))
                udl_handle_damage(fb, &shadow_plane_state->data[0], &rect);
+
+       drm_dev_exit(idx);
 }
 
 static const struct drm_plane_helper_funcs udl_primary_plane_helper_funcs = {
@@ -339,10 +347,14 @@ static void udl_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atom
        struct drm_display_mode *mode = &crtc_state->mode;
        struct urb *urb;
        char *buf;
+       int idx;
+
+       if (!drm_dev_enter(dev, &idx))
+               return;
 
        urb = udl_get_urb(dev);
        if (!urb)
-               return;
+               goto out;
 
        buf = (char *)urb->transfer_buffer;
        buf = udl_vidreg_lock(buf);
@@ -357,6 +369,9 @@ static void udl_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atom
        buf = udl_dummy_render(buf);
 
        udl_submit_urb(dev, urb, buf - (char *)urb->transfer_buffer);
+
+out:
+       drm_dev_exit(idx);
 }
 
 static void udl_crtc_helper_atomic_disable(struct drm_crtc *crtc, struct drm_atomic_state *state)
@@ -364,10 +379,14 @@ static void udl_crtc_helper_atomic_disable(struct drm_crtc *crtc, struct drm_ato
        struct drm_device *dev = crtc->dev;
        struct urb *urb;
        char *buf;
+       int idx;
+
+       if (!drm_dev_enter(dev, &idx))
+               return;
 
        urb = udl_get_urb(dev);
        if (!urb)
-               return;
+               goto out;
 
        buf = (char *)urb->transfer_buffer;
        buf = udl_vidreg_lock(buf);
@@ -376,6 +395,9 @@ static void udl_crtc_helper_atomic_disable(struct drm_crtc *crtc, struct drm_ato
        buf = udl_dummy_render(buf);
 
        udl_submit_urb(dev, urb, buf - (char *)urb->transfer_buffer);
+
+out:
+       drm_dev_exit(idx);
 }
 
 static const struct drm_crtc_helper_funcs udl_crtc_helper_funcs = {
@@ -462,17 +484,26 @@ err_kfree:
 
 static enum drm_connector_status udl_connector_detect(struct drm_connector *connector, bool force)
 {
-       struct udl_device *udl = to_udl(connector->dev);
+       struct drm_device *dev = connector->dev;
+       struct udl_device *udl = to_udl(dev);
        struct udl_connector *udl_connector = to_udl_connector(connector);
+       enum drm_connector_status status = connector_status_disconnected;
+       int idx;
 
        /* cleanup previous EDID */
        kfree(udl_connector->edid);
+       udl_connector->edid = NULL;
 
-       udl_connector->edid = drm_do_get_edid(connector, udl_get_edid_block, udl);
-       if (!udl_connector->edid)
+       if (!drm_dev_enter(dev, &idx))
                return connector_status_disconnected;
 
-       return connector_status_connected;
+       udl_connector->edid = drm_do_get_edid(connector, udl_get_edid_block, udl);
+       if (udl_connector->edid)
+               status = connector_status_connected;
+
+       drm_dev_exit(idx);
+
+       return status;
 }
 
 static void udl_connector_destroy(struct drm_connector *connector)