linux-kernel - [PATCH 4.8 008/125] drm/amdgpu/dce11: disable hpd on local panels

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Date:   Sat, 29 Oct 2016 09:48:46 -0400
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Alex Deucher <alexander.deucher@....com>
Subject: [PATCH 4.8 008/125] drm/amdgpu/dce11: disable hpd on local panels

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alex Deucher <alexander.deucher@....com>

commit 3a9d993ee9809c217f4322623a9b78c8d17fdd1f upstream.

Otherwise we can get a hotplug interrupt storm when
we turn the panel off if hpd interrupts were enabled
by the bios.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=97471

Signed-off-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/gpu/drm/amd/amdgpu/dce_v11_0.c |   23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
@@ -443,16 +443,6 @@ static void dce_v11_0_hpd_init(struct am
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 		struct amdgpu_connector *amdgpu_connector = to_amdgpu_connector(connector);
 
-		if (connector->connector_type == DRM_MODE_CONNECTOR_eDP ||
-		    connector->connector_type == DRM_MODE_CONNECTOR_LVDS) {
-			/* don't try to enable hpd on eDP or LVDS avoid breaking the
-			 * aux dp channel on imac and help (but not completely fix)
-			 * https://bugzilla.redhat.com/show_bug.cgi?id=726143
-			 * also avoid interrupt storms during dpms.
-			 */
-			continue;
-		}
-
 		switch (amdgpu_connector->hpd.hpd) {
 		case AMDGPU_HPD_1:
 			idx = 0;
@@ -476,6 +466,19 @@ static void dce_v11_0_hpd_init(struct am
 			continue;
 		}
 
+		if (connector->connector_type == DRM_MODE_CONNECTOR_eDP ||
+		    connector->connector_type == DRM_MODE_CONNECTOR_LVDS) {
+			/* don't try to enable hpd on eDP or LVDS avoid breaking the
+			 * aux dp channel on imac and help (but not completely fix)
+			 * https://bugzilla.redhat.com/show_bug.cgi?id=726143
+			 * also avoid interrupt storms during dpms.
+			 */
+			tmp = RREG32(mmDC_HPD_INT_CONTROL + hpd_offsets[idx]);
+			tmp = REG_SET_FIELD(tmp, DC_HPD_INT_CONTROL, DC_HPD_INT_EN, 0);
+			WREG32(mmDC_HPD_INT_CONTROL + hpd_offsets[idx], tmp);
+			continue;
+		}
+
 		tmp = RREG32(mmDC_HPD_CONTROL + hpd_offsets[idx]);
 		tmp = REG_SET_FIELD(tmp, DC_HPD_CONTROL, DC_HPD_EN, 1);
 		WREG32(mmDC_HPD_CONTROL + hpd_offsets[idx], tmp);