[PATCH 4/4] drm/i915/display: Implement Wa_14021768792 for BMG DP for link_m/n ratio > 10
Ankit Nautiyal
ankit.k.nautiyal at intel.com
Fri Mar 21 11:26:50 UTC 2025
Handle the bypass logic for the M/N ratio limit for DP.
Calculate the M/N ratio, check if it can bypass the limit, and set the
appropriate flags for the workaround.
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
---
drivers/gpu/drm/i915/display/intel_display.c | 1 -
drivers/gpu/drm/i915/display/intel_display.h | 3 ++
drivers/gpu/drm/i915/display/intel_dp.c | 31 ++++++++++++++++++--
drivers/gpu/drm/i915/display/intel_dp.h | 4 +++
drivers/gpu/drm/i915/display/intel_dp_mst.c | 5 +++-
5 files changed, 40 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 8a6b9196ef9b..ede86012406b 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -3391,7 +3391,6 @@ void bmg_bypass_m_n_limit_read(struct intel_crtc *crtc,
m_n->bypass_m_n_ratio_limit = true;
}
-static
int bmg_can_bypass_m_n_limit(struct intel_display *display,
int m_n_ratio,
enum pipe pipe)
diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
index 7a33c57d5abe..651ec3eb8726 100644
--- a/drivers/gpu/drm/i915/display/intel_display.h
+++ b/drivers/gpu/drm/i915/display/intel_display.h
@@ -574,5 +574,8 @@ int intel_link_compute_m_n(struct intel_display *display,
int pixel_clock, int link_clock,
int bw_overhead,
struct intel_link_m_n *m_n);
+int bmg_can_bypass_m_n_limit(struct intel_display *display,
+ int m_n_ratio,
+ enum pipe pipe);
#endif
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 49a8f105ba26..56aebb23d8ae 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2937,6 +2937,27 @@ static bool can_enable_drrs(struct intel_connector *connector,
intel_panel_drrs_type(connector) == DRRS_TYPE_SEAMLESS;
}
+bool
+intel_dp_bmg_bypass_m_n_limit(struct intel_display *display,
+ struct intel_link_m_n *m_n,
+ enum pipe pipe)
+{
+ int m_n_ratio;
+
+ if (!m_n->link_n)
+ return false;
+
+ m_n_ratio = DIV_ROUND_UP(m_n->link_m, m_n->link_n);
+
+ if (!bmg_can_bypass_m_n_limit(display, m_n_ratio, pipe))
+ return false;
+
+ m_n->bypass_m_n_ratio_limit = true;
+ drm_dbg_kms(display->drm, "Bypassing Link_m/Link_n ratio limit\n");
+
+ return true;
+}
+
static int
intel_dp_drrs_compute_config(struct intel_connector *connector,
struct intel_crtc_state *pipe_config,
@@ -2945,6 +2966,8 @@ intel_dp_drrs_compute_config(struct intel_connector *connector,
struct intel_display *display = to_intel_display(connector);
const struct drm_display_mode *downclock_mode =
intel_panel_downclock_mode(connector, &pipe_config->hw.adjusted_mode);
+ struct intel_crtc *crtc = to_intel_crtc(pipe_config->uapi.crtc);
+ enum pipe pipe = crtc->pipe;
int pixel_clock;
int ret;
@@ -2975,7 +2998,8 @@ intel_dp_drrs_compute_config(struct intel_connector *connector,
pipe_config->port_clock,
intel_dp_bw_fec_overhead(pipe_config->fec_enable),
&pipe_config->dp_m2_n2);
- if (ret)
+
+ if (ret && !intel_dp_bmg_bypass_m_n_limit(display, &pipe_config->dp_m2_n2, pipe))
return ret;
/* FIXME: abstract this better */
@@ -3101,6 +3125,8 @@ intel_dp_compute_config(struct intel_encoder *encoder,
struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
const struct drm_display_mode *fixed_mode;
struct intel_connector *connector = intel_dp->attached_connector;
+ struct intel_crtc *crtc = to_intel_crtc(pipe_config->uapi.crtc);
+ enum pipe pipe = crtc->pipe;
int ret = 0, link_bpp_x16;
fixed_mode = intel_panel_fixed_mode(connector, adjusted_mode);
@@ -3130,7 +3156,8 @@ intel_dp_compute_config(struct intel_encoder *encoder,
ret = intel_dp_compute_output_format(encoder, pipe_config, conn_state, true);
if (ret)
ret = intel_dp_compute_output_format(encoder, pipe_config, conn_state, false);
- if (ret)
+
+ if (ret && !intel_dp_bmg_bypass_m_n_limit(display, &pipe_config->dp_m_n, pipe))
return ret;
if ((intel_dp_is_edp(intel_dp) && fixed_mode) ||
diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h
index 9189db4c2594..16004a18b13e 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.h
+++ b/drivers/gpu/drm/i915/display/intel_dp.h
@@ -22,6 +22,7 @@ struct intel_digital_port;
struct intel_display;
struct intel_dp;
struct intel_encoder;
+struct intel_link_m_n;
struct link_config_limits {
int min_rate, max_rate;
@@ -208,5 +209,8 @@ bool intel_dp_has_connector(struct intel_dp *intel_dp,
const struct drm_connector_state *conn_state);
int intel_dp_dsc_max_src_input_bpc(struct intel_display *display);
int intel_dp_dsc_min_src_input_bpc(void);
+bool intel_dp_bmg_bypass_m_n_limit(struct intel_display *display,
+ struct intel_link_m_n *m_n,
+ enum pipe pipe);
#endif /* __INTEL_DP_H__ */
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 18d75634f902..f03a1c97cdcf 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -175,6 +175,8 @@ static int intel_dp_mst_compute_m_n(const struct intel_crtc_state *crtc_state,
const struct drm_display_mode *adjusted_mode =
&crtc_state->hw.adjusted_mode;
struct intel_display *display = to_intel_display(crtc_state);
+ struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+ enum pipe pipe = crtc->pipe;
int ret;
/* TODO: Check WA 14013163432 to set data M/N for full BW utilization. */
@@ -182,7 +184,8 @@ static int intel_dp_mst_compute_m_n(const struct intel_crtc_state *crtc_state,
adjusted_mode->crtc_clock,
crtc_state->port_clock,
overhead, m_n);
- if (ret)
+
+ if (ret && !intel_dp_bmg_bypass_m_n_limit(display, m_n, pipe))
return ret;
m_n->tu = DIV_ROUND_UP_ULL(mul_u32_u32(m_n->data_m, 64), m_n->data_n);
--
2.45.2
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