From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Windows/BIOS always uses fixed N values. Let's match that
behaviour.
Allows us to also get rid of that constant_n quirk stuff.
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_display.c | 36 +++++++++-----------
drivers/gpu/drm/i915/display/intel_display.h | 2 +-
drivers/gpu/drm/i915/display/intel_dp.c | 10 +++---
drivers/gpu/drm/i915/display/intel_dp_mst.c | 3 +-
drivers/gpu/drm/i915/display/intel_fdi.c | 2 +-
5 files changed, 24 insertions(+), 29 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 43c00f8b4057..5ec954b293a2 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -2726,19 +2726,11 @@ intel_reduce_m_n_ratio(u32 *num, u32 *den)
}
}
-static void compute_m_n(unsigned int m, unsigned int n,
- u32 *ret_m, u32 *ret_n,
- bool constant_n)
+static void compute_m_n(u32 *ret_m, u32 *ret_n,
+ u32 m, u32 n, u32 constant_n)
{
- /*
- * Several DP dongles in particular seem to be fussy about
- * too large link M/N values. Give N value as 0x8000 that
- * should be acceptable by specific devices. 0x8000 is the
- * specified fixed N value for asynchronous clock mode,
- * which the devices expect also in synchronous clock mode.
- */
if (constant_n)
- *ret_n = DP_LINK_CONSTANT_N_VALUE;
+ *ret_n = constant_n;
else
*ret_n = min_t(unsigned int, roundup_pow_of_two(n), DATA_LINK_N_MAX);
@@ -2750,22 +2742,28 @@ void
intel_link_compute_m_n(u16 bits_per_pixel, int nlanes,
int pixel_clock, int link_clock,
struct intel_link_m_n *m_n,
- bool constant_n, bool fec_enable)
+ bool fec_enable)
{
u32 data_clock = bits_per_pixel * pixel_clock;
if (fec_enable)
data_clock = intel_dp_mode_to_fec_clock(data_clock);
+ /*
+ * Windows/BIOS uses fixed M/N values always. Follow suit.
+ *
+ * Also several DP dongles in particular seem to be fussy
+ * about too large link M/N values. Presumably the 20bit
+ * value used by Windows/BIOS is acceptable to everyone.
+ */
m_n->tu = 64;
- compute_m_n(data_clock,
- link_clock * nlanes * 8,
- &m_n->data_m, &m_n->data_n,
- constant_n);
+ compute_m_n(&m_n->data_m, &m_n->data_n,
+ data_clock, link_clock * nlanes * 8,
+ 0x8000000);
- compute_m_n(pixel_clock, link_clock,
- &m_n->link_m, &m_n->link_n,
- constant_n);
+ compute_m_n(&m_n->link_m, &m_n->link_n,
+ pixel_clock, link_clock,
+ 0x80000);
}
static void intel_panel_sanitize_ssc(struct drm_i915_private *dev_priv)
diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
index 8610e17cc593..e00a6022acf8 100644
--- a/drivers/gpu/drm/i915/display/intel_display.h
+++ b/drivers/gpu/drm/i915/display/intel_display.h
@@ -547,7 +547,7 @@ u8 intel_calc_active_pipes(struct intel_atomic_state *state,
void intel_link_compute_m_n(u16 bpp, int nlanes,
int pixel_clock, int link_clock,
struct intel_link_m_n *m_n,
- bool constant_n, bool fec_enable);
+ bool fec_enable);
u32 intel_plane_fb_max_stride(struct drm_i915_private *dev_priv,
u32 pixel_format, u64 modifier);
enum drm_mode_status
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 90fa8eda6911..40c451d1ee85 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1930,7 +1930,7 @@ static bool can_enable_drrs(struct intel_connector *connector,
static void
intel_dp_drrs_compute_config(struct intel_connector *connector,
struct intel_crtc_state *pipe_config,
- int output_bpp, bool constant_n)
+ int output_bpp)
{
struct drm_i915_private *i915 = to_i915(connector->base.dev);
const struct drm_display_mode *downclock_mode =
@@ -1957,7 +1957,7 @@ intel_dp_drrs_compute_config(struct intel_connector *connector,
intel_link_compute_m_n(output_bpp, pipe_config->lane_count, pixel_clock,
pipe_config->port_clock, &pipe_config->dp_m2_n2,
- constant_n, pipe_config->fec_enable);
+ pipe_config->fec_enable);
/* FIXME: abstract this better */
if (pipe_config->splitter.enable)
@@ -2032,7 +2032,6 @@ 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;
- bool constant_n = drm_dp_has_quirk(&intel_dp->desc, DP_DPCD_QUIRK_CONSTANT_N);
int ret = 0, output_bpp;
if (HAS_PCH_SPLIT(dev_priv) && !HAS_DDI(dev_priv) && encoder->port != PORT_A)
@@ -2111,7 +2110,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
adjusted_mode->crtc_clock,
pipe_config->port_clock,
&pipe_config->dp_m_n,
- constant_n, pipe_config->fec_enable);
+ pipe_config->fec_enable);
/* FIXME: abstract this better */
if (pipe_config->splitter.enable)
@@ -2122,8 +2121,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
intel_vrr_compute_config(pipe_config, conn_state);
intel_psr_compute_config(intel_dp, pipe_config, conn_state);
- intel_dp_drrs_compute_config(connector, pipe_config,
- output_bpp, constant_n);
+ intel_dp_drrs_compute_config(connector, pipe_config, output_bpp);
intel_dp_compute_vsc_sdp(intel_dp, pipe_config, conn_state);
intel_dp_compute_hdr_metadata_infoframe_sdp(intel_dp, pipe_config, conn_state);
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 061b277e5ce7..00e55555091a 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -57,7 +57,6 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
struct drm_i915_private *i915 = to_i915(connector->base.dev);
const struct drm_display_mode *adjusted_mode =
&crtc_state->hw.adjusted_mode;
- bool constant_n = drm_dp_has_quirk(&intel_dp->desc, DP_DPCD_QUIRK_CONSTANT_N);
int bpp, slots = -EINVAL;
crtc_state->lane_count = limits->max_lane_count;
@@ -93,7 +92,7 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
adjusted_mode->crtc_clock,
crtc_state->port_clock,
&crtc_state->dp_m_n,
- constant_n, crtc_state->fec_enable);
+ crtc_state->fec_enable);
crtc_state->dp_m_n.tu = slots;
return 0;
diff --git a/drivers/gpu/drm/i915/display/intel_fdi.c b/drivers/gpu/drm/i915/display/intel_fdi.c
index 67d2484afbaa..0dc6414a56c4 100644
--- a/drivers/gpu/drm/i915/display/intel_fdi.c
+++ b/drivers/gpu/drm/i915/display/intel_fdi.c
@@ -256,7 +256,7 @@ int ilk_fdi_compute_config(struct intel_crtc *crtc,
pipe_config->fdi_lanes = lane;
intel_link_compute_m_n(pipe_config->pipe_bpp, lane, fdi_dotclock,
- link_bw, &pipe_config->fdi_m_n, false, false);
+ link_bw, &pipe_config->fdi_m_n, false);
ret = ilk_check_fdi_lanes(dev, crtc->pipe, pipe_config);
if (ret == -EDEADLK)
--
2.35.1
