[PATCH 4.4 05/51] drm/amdgpu/dce11: disable hpd on local panels

From: Greg Kroah-Hartman
Date: Sat Oct 29 2016 - 10:25:46 EST


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

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

From: Alex Deucher <alexander.deucher@xxxxxxx>

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@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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
@@ -409,16 +409,6 @@ 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;
@@ -442,6 +432,19 @@ 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);