6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Imre Deak <imre.deak@xxxxxxxxx>
commit 69b3d87212676c4c22aa4660435e2066dc7d1311 upstream.
The MST branch device may not support the number of DSC slices a mode
requires, handle the error in this case.
Fixes: 4e0837a8d00a ("drm/i915/dp_mst: Account for FEC and DSC overhead during BW allocation")
Cc: stable@xxxxxxxxxxxxxxx # v6.8+
Reviewed-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20241009110135.1216498-1-imre.deak@xxxxxxxxx
(cherry picked from commit 802a69b6b8a0502a9e2309afec7e1b77f67874f2)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_dp_mst.c | 37 ++++++++++++++++++++--------
1 file changed, 27 insertions(+), 10 deletions(-)
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -88,25 +88,19 @@ static int intel_dp_mst_max_dpt_bpp(cons
static int intel_dp_mst_bw_overhead(const struct intel_crtc_state *crtc_state,
const struct intel_connector *connector,
- bool ssc, bool dsc, int bpp_x16)
+ bool ssc, int dsc_slice_count, int bpp_x16)
{
const struct drm_display_mode *adjusted_mode =
&crtc_state->hw.adjusted_mode;
unsigned long flags = DRM_DP_BW_OVERHEAD_MST;
- int dsc_slice_count = 0;
int overhead;
flags |= intel_dp_is_uhbr(crtc_state) ? DRM_DP_BW_OVERHEAD_UHBR : 0;
flags |= ssc ? DRM_DP_BW_OVERHEAD_SSC_REF_CLK : 0;
flags |= crtc_state->fec_enable ? DRM_DP_BW_OVERHEAD_FEC : 0;
- if (dsc) {
+ if (dsc_slice_count)
flags |= DRM_DP_BW_OVERHEAD_DSC;
- dsc_slice_count = intel_dp_dsc_get_slice_count(connector,
- adjusted_mode->clock,
- adjusted_mode->hdisplay,
- crtc_state->joiner_pipes);
- }
overhead = drm_dp_bw_overhead(crtc_state->lane_count,
adjusted_mode->hdisplay,
@@ -152,6 +146,19 @@ static int intel_dp_mst_calc_pbn(int pix
return DIV_ROUND_UP(effective_data_rate * 64, 54 * 1000);
}
+static int intel_dp_mst_dsc_get_slice_count(const struct intel_connector *connector,
+ const struct intel_crtc_state *crtc_state)
+{
+ const struct drm_display_mode *adjusted_mode =
+ &crtc_state->hw.adjusted_mode;
+ int num_joined_pipes = crtc_state->joiner_pipes;
+
+ return intel_dp_dsc_get_slice_count(connector,
+ adjusted_mode->clock,
+ adjusted_mode->hdisplay,
+ num_joined_pipes);
+}
+
static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder,
struct intel_crtc_state *crtc_state,
int max_bpp,
@@ -171,6 +178,7 @@ static int intel_dp_mst_find_vcpi_slots_
const struct drm_display_mode *adjusted_mode =
&crtc_state->hw.adjusted_mode;
int bpp, slots = -EINVAL;
+ int dsc_slice_count = 0;
int max_dpt_bpp;
int ret = 0;
@@ -202,6 +210,15 @@ static int intel_dp_mst_find_vcpi_slots_
drm_dbg_kms(&i915->drm, "Looking for slots in range min bpp %d max bpp %d\n",
min_bpp, max_bpp);
+ if (dsc) {
+ dsc_slice_count = intel_dp_mst_dsc_get_slice_count(connector, crtc_state);
+ if (!dsc_slice_count) {
+ drm_dbg_kms(&i915->drm, "Can't get valid DSC slice count\n");
+
+ return -ENOSPC;
+ }
+ }
+
for (bpp = max_bpp; bpp >= min_bpp; bpp -= step) {
int local_bw_overhead;
int remote_bw_overhead;
@@ -215,9 +232,9 @@ static int intel_dp_mst_find_vcpi_slots_
intel_dp_output_bpp(crtc_state->output_format, bpp));
local_bw_overhead = intel_dp_mst_bw_overhead(crtc_state, connector,
- false, dsc, link_bpp_x16);
+ false, dsc_slice_count, link_bpp_x16);
remote_bw_overhead = intel_dp_mst_bw_overhead(crtc_state, connector,
- true, dsc, link_bpp_x16);
+ true, dsc_slice_count, link_bpp_x16);
intel_dp_mst_compute_m_n(crtc_state, connector,
local_bw_overhead,
