Merge remote-tracking branch 'drm/drm-next' into drm-misc-next

Pull in drm-intel-next for the updates to drm panic handling.

Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>

1 files changed, 30 insertions, 14 deletions

diff --git a/drivers/gpu/drm/display/drm_dp_helper.c b/drivers/gpu/drm/display/drm_dp_helper.c
index 5d8a4691af2c..1c3920297906 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -693,6 +693,34 @@ void drm_dp_dpcd_set_powered(struct drm_dp_aux *aux, bool powered)
 EXPORT_SYMBOL(drm_dp_dpcd_set_powered);
 
 /**
+ * drm_dp_dpcd_set_probe() - Set whether a probing before DPCD access is done
+ * @aux: DisplayPort AUX channel
+ * @enable: Enable the probing if required
+ */
+void drm_dp_dpcd_set_probe(struct drm_dp_aux *aux, bool enable)
+{
+	WRITE_ONCE(aux->dpcd_probe_disabled, !enable);
+}
+EXPORT_SYMBOL(drm_dp_dpcd_set_probe);
+
+static bool dpcd_access_needs_probe(struct drm_dp_aux *aux)
+{
+	/*
+	 * HP ZR24w corrupts the first DPCD access after entering power save
+	 * mode. Eg. on a read, the entire buffer will be filled with the same
+	 * byte. Do a throw away read to avoid corrupting anything we care
+	 * about. Afterwards things will work correctly until the monitor
+	 * gets woken up and subsequently re-enters power save mode.
+	 *
+	 * The user pressing any button on the monitor is enough to wake it
+	 * up, so there is no particularly good place to do the workaround.
+	 * We just have to do it before any DPCD access and hope that the
+	 * monitor doesn't power down exactly after the throw away read.
+	 */
+	return !aux->is_remote && !READ_ONCE(aux->dpcd_probe_disabled);
+}
+
+/**
  * drm_dp_dpcd_read() - read a series of bytes from the DPCD
  * @aux: DisplayPort AUX channel (SST or MST)
  * @offset: address of the (first) register to read
@@ -713,20 +741,8 @@ ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
 {
 	int ret;
 
-	/*
-	 * HP ZR24w corrupts the first DPCD access after entering power save
-	 * mode. Eg. on a read, the entire buffer will be filled with the same
-	 * byte. Do a throw away read to avoid corrupting anything we care
-	 * about. Afterwards things will work correctly until the monitor
-	 * gets woken up and subsequently re-enters power save mode.
-	 *
-	 * The user pressing any button on the monitor is enough to wake it
-	 * up, so there is no particularly good place to do the workaround.
-	 * We just have to do it before any DPCD access and hope that the
-	 * monitor doesn't power down exactly after the throw away read.
-	 */
-	if (!aux->is_remote) {
-		ret = drm_dp_dpcd_probe(aux, DP_DPCD_REV);
+	if (dpcd_access_needs_probe(aux)) {
+		ret = drm_dp_dpcd_probe(aux, DP_LANE0_1_STATUS);
 		if (ret < 0)
 			return ret;
 	}