drm/nouveau/disp: add method to control DPAUX pad power

This removes the need for NVKM to track DP HPD events, as the KMS
driver follows them already, and has better information available.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

1 files changed, 42 insertions, 48 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c
index f1887b58f472..92c9faecffae 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c
@@ -612,18 +612,38 @@ nvkm_dp_enable_supported_link_rates(struct nvkm_outp *outp)
 	return outp->dp.rates != 0;
 }
 
-static bool
-nvkm_dp_enable(struct nvkm_outp *outp, bool enable)
+void
+nvkm_dp_enable(struct nvkm_outp *outp, bool auxpwr)
 {
+	struct nvkm_gpio *gpio = outp->disp->engine.subdev.device->gpio;
 	struct nvkm_i2c_aux *aux = outp->dp.aux;
 
-	if (enable) {
-		if (!outp->dp.present) {
-			OUTP_DBG(outp, "aux power -> always");
-			nvkm_i2c_aux_monitor(aux, true);
-			outp->dp.present = true;
+	if (auxpwr && !outp->dp.aux_pwr) {
+		/* eDP panels need powering on by us (if the VBIOS doesn't default it
+		 * to on) before doing any AUX channel transactions.  LVDS panel power
+		 * is handled by the SOR itself, and not required for LVDS DDC.
+		 */
+		if (outp->conn->info.type == DCB_CONNECTOR_eDP) {
+			int power = nvkm_gpio_get(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff);
+			if (power == 0) {
+				nvkm_gpio_set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 1);
+				outp->dp.aux_pwr_pu = true;
+			}
+
+			/* We delay here unconditionally, even if already powered,
+			 * because some laptop panels having a significant resume
+			 * delay before the panel begins responding.
+			 *
+			 * This is likely a bit of a hack, but no better idea for
+			 * handling this at the moment.
+			 */
+			msleep(300);
 		}
 
+		OUTP_DBG(outp, "aux power -> always");
+		nvkm_i2c_aux_monitor(aux, true);
+		outp->dp.aux_pwr = true;
+
 		/* Detect any LTTPRs before reading DPCD receiver caps. */
 		if (!nvkm_rdaux(aux, DPCD_LTTPR_REV, outp->dp.lttpr, sizeof(outp->dp.lttpr)) &&
 		    outp->dp.lttpr[0] >= 0x14 && outp->dp.lttpr[2]) {
@@ -676,19 +696,24 @@ nvkm_dp_enable(struct nvkm_outp *outp, bool enable)
 					outp->dp.rates++;
 				}
 			}
-
-			return true;
 		}
-	}
-
-	if (outp->dp.present) {
+	} else
+	if (!auxpwr && outp->dp.aux_pwr) {
 		OUTP_DBG(outp, "aux power -> demand");
 		nvkm_i2c_aux_monitor(aux, false);
-		outp->dp.present = false;
-	}
+		outp->dp.aux_pwr = false;
+		atomic_set(&outp->dp.lt.done, 0);
 
-	atomic_set(&outp->dp.lt.done, 0);
-	return false;
+		/* Restore eDP panel GPIO to its prior state if we changed it, as
+		 * it could potentially interfere with other outputs.
+		 */
+		if (outp->conn->info.type == DCB_CONNECTOR_eDP) {
+			if (outp->dp.aux_pwr_pu) {
+				nvkm_gpio_set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 0);
+				outp->dp.aux_pwr_pu = false;
+			}
+		}
+	}
 }
 
 static int
@@ -705,8 +730,6 @@ nvkm_dp_hpd(struct nvkm_notify *notify)
 		if (atomic_read(&outp->dp.lt.done))
 			outp->func->acquire(outp);
 		rep.mask |= NVIF_NOTIFY_CONN_V0_IRQ;
-	} else {
-		nvkm_dp_enable(outp, true);
 	}
 
 	if (line->mask & NVKM_I2C_UNPLUG)
@@ -728,37 +751,8 @@ nvkm_dp_fini(struct nvkm_outp *outp)
 static void
 nvkm_dp_init(struct nvkm_outp *outp)
 {
-	struct nvkm_gpio *gpio = outp->disp->engine.subdev.device->gpio;
-
+	nvkm_dp_enable(outp, outp->dp.enabled);
 	nvkm_notify_put(&outp->conn->hpd);
-
-	/* eDP panels need powering on by us (if the VBIOS doesn't default it
-	 * to on) before doing any AUX channel transactions.  LVDS panel power
-	 * is handled by the SOR itself, and not required for LVDS DDC.
-	 */
-	if (outp->conn->info.type == DCB_CONNECTOR_eDP) {
-		int power = nvkm_gpio_get(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff);
-		if (power == 0)
-			nvkm_gpio_set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 1);
-
-		/* We delay here unconditionally, even if already powered,
-		 * because some laptop panels having a significant resume
-		 * delay before the panel begins responding.
-		 *
-		 * This is likely a bit of a hack, but no better idea for
-		 * handling this at the moment.
-		 */
-		msleep(300);
-
-		/* If the eDP panel can't be detected, we need to restore
-		 * the panel power GPIO to avoid breaking another output.
-		 */
-		if (!nvkm_dp_enable(outp, true) && power == 0)
-			nvkm_gpio_set(gpio, 0, DCB_GPIO_PANEL_POWER, 0xff, 0);
-	} else {
-		nvkm_dp_enable(outp, true);
-	}
-
 	nvkm_notify_get(&outp->dp.hpd);
 }