drm: disable encoders before re-routing them
In some cases we may receive a mode config that has a different
CRTC<->encoder map that the current configuration. In that case, we
need to disable any re-routed encoders before setting the mode,
otherwise they may not pick up the new CRTC (if the output types are
incompatible for example).
Tested-by: Kristian Høgsberg <krh@bitplanet.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index 733028b..1c3a8c5 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -452,6 +452,59 @@
kfree(modes);
kfree(enabled);
}
+
+/**
+ * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
+ * @encoder: encoder to test
+ * @crtc: crtc to test
+ *
+ * Return false if @encoder can't be driven by @crtc, true otherwise.
+ */
+static bool drm_encoder_crtc_ok(struct drm_encoder *encoder,
+ struct drm_crtc *crtc)
+{
+ struct drm_device *dev;
+ struct drm_crtc *tmp;
+ int crtc_mask = 1;
+
+ WARN(!crtc, "checking null crtc?");
+
+ dev = crtc->dev;
+
+ list_for_each_entry(tmp, &dev->mode_config.crtc_list, head) {
+ if (tmp == crtc)
+ break;
+ crtc_mask <<= 1;
+ }
+
+ if (encoder->possible_crtcs & crtc_mask)
+ return true;
+ return false;
+}
+
+/*
+ * Check the CRTC we're going to map each output to vs. its current
+ * CRTC. If they don't match, we have to disable the output and the CRTC
+ * since the driver will have to re-route things.
+ */
+static void
+drm_crtc_prepare_encoders(struct drm_device *dev)
+{
+ struct drm_encoder_helper_funcs *encoder_funcs;
+ struct drm_encoder *encoder;
+
+ list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
+ encoder_funcs = encoder->helper_private;
+ /* Disable unused encoders */
+ if (encoder->crtc == NULL)
+ (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
+ /* Disable encoders whose CRTC is about to change */
+ if (encoder_funcs->get_crtc &&
+ encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
+ (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
+ }
+}
+
/**
* drm_crtc_set_mode - set a mode
* @crtc: CRTC to program
@@ -547,6 +600,8 @@
encoder_funcs->prepare(encoder);
}
+ drm_crtc_prepare_encoders(dev);
+
crtc_funcs->prepare(crtc);
/* Set up the DPLL and any encoders state that needs to adjust or depend
@@ -617,7 +672,7 @@
struct drm_device *dev;
struct drm_crtc **save_crtcs, *new_crtc;
struct drm_encoder **save_encoders, *new_encoder;
- struct drm_framebuffer *old_fb;
+ struct drm_framebuffer *old_fb = NULL;
bool save_enabled;
bool mode_changed = false;
bool fb_changed = false;
@@ -668,9 +723,10 @@
* and then just flip_or_move it */
if (set->crtc->fb != set->fb) {
/* If we have no fb then treat it as a full mode set */
- if (set->crtc->fb == NULL)
+ if (set->crtc->fb == NULL) {
+ DRM_DEBUG("crtc has no fb, full mode set\n");
mode_changed = true;
- else if ((set->fb->bits_per_pixel !=
+ } else if ((set->fb->bits_per_pixel !=
set->crtc->fb->bits_per_pixel) ||
set->fb->depth != set->crtc->fb->depth)
fb_changed = true;
@@ -682,7 +738,7 @@
fb_changed = true;
if (set->mode && !drm_mode_equal(set->mode, &set->crtc->mode)) {
- DRM_DEBUG("modes are different\n");
+ DRM_DEBUG("modes are different, full mode set\n");
drm_mode_debug_printmodeline(&set->crtc->mode);
drm_mode_debug_printmodeline(set->mode);
mode_changed = true;
@@ -708,6 +764,7 @@
}
if (new_encoder != connector->encoder) {
+ DRM_DEBUG("encoder changed, full mode switch\n");
mode_changed = true;
connector->encoder = new_encoder;
}
@@ -734,10 +791,20 @@
if (set->connectors[ro] == connector)
new_crtc = set->crtc;
}
+
+ /* Make sure the new CRTC will work with the encoder */
+ if (new_crtc &&
+ !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
+ ret = -EINVAL;
+ goto fail_set_mode;
+ }
if (new_crtc != connector->encoder->crtc) {
+ DRM_DEBUG("crtc changed, full mode switch\n");
mode_changed = true;
connector->encoder->crtc = new_crtc;
}
+ DRM_DEBUG("setting connector %d crtc to %p\n",
+ connector->base.id, new_crtc);
}
/* mode_set_base is not a required function */
@@ -781,6 +848,7 @@
fail_set_mode:
set->crtc->enabled = save_enabled;
+ set->crtc->fb = old_fb;
count = 0;
list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
if (!connector->encoder)