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drm/i915/dp: Use drm_dp_max_dprx_data_rate()

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Instead of intel_dp_max_data_rate() use the equivalent
drm_dp_max_dprx_data_rate() which was copied from the former one in a
previous patch.

Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240220211841.448846-6-imre.deak@intel.com
This commit is contained in:
Imre Deak
2024-02-20 23:18:25 +02:00
parent d1e217d44b
commit 204863d668
4 changed files with 10 additions and 57 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/gpu/drm/i915/display/intel_display.c
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@@ -2478,7 +2478,7 @@ intel_link_compute_m_n(u16 bits_per_pixel_x16, int nlanes,
u32 link_symbol_clock = intel_dp_link_symbol_clock(link_clock);
u32 data_m = intel_dp_effective_data_rate(pixel_clock, bits_per_pixel_x16,
bw_overhead);
u32 data_n = intel_dp_max_data_rate(link_clock, nlanes);
u32 data_n = drm_dp_max_dprx_data_rate(link_clock, nlanes);
/*
* Windows/BIOS uses fixed M/N values always. Follow suit.

62
drivers/gpu/drm/i915/display/intel_dp.c
View File

@@ -383,52 +383,6 @@ int intel_dp_effective_data_rate(int pixel_clock, int bpp_x16,
1000000 * 16 * 8);
}
/*
* Given a link rate and lanes, get the data bandwidth.
*
* Data bandwidth is the actual payload rate, which depends on the data
* bandwidth efficiency and the link rate.
*
* For 8b/10b channel encoding, SST and non-FEC, the data bandwidth efficiency
* is 80%. For example, for a 1.62 Gbps link, 1.62*10^9 bps * 0.80 * (1/8) =
* 162000 kBps. With 8-bit symbols, we have 162000 kHz symbol clock. Just by
* coincidence, the port clock in kHz matches the data bandwidth in kBps, and
* they equal the link bit rate in Gbps multiplied by 100000. (Note that this no
* longer holds for data bandwidth as soon as FEC or MST is taken into account!)
*
* For 128b/132b channel encoding, the data bandwidth efficiency is 96.71%. For
* example, for a 10 Gbps link, 10*10^9 bps * 0.9671 * (1/8) = 1208875
* kBps. With 32-bit symbols, we have 312500 kHz symbol clock. The value 1000000
* does not match the symbol clock, the port clock (not even if you think in
* terms of a byte clock), nor the data bandwidth. It only matches the link bit
* rate in units of 10000 bps.
*/
int
intel_dp_max_data_rate(int max_link_rate, int max_lanes)
{
int ch_coding_efficiency =
drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(max_link_rate));
int max_link_rate_kbps = max_link_rate * 10;
/*
* UHBR rates always use 128b/132b channel encoding, and have
* 97.71% data bandwidth efficiency. Consider max_link_rate the
* link bit rate in units of 10000 bps.
*/
/*
* Lower than UHBR rates always use 8b/10b channel encoding, and have
* 80% data bandwidth efficiency for SST non-FEC. However, this turns
* out to be a nop by coincidence:
*
* int max_link_rate_kbps = max_link_rate * 10;
* max_link_rate_kbps = DIV_ROUND_DOWN_ULL(max_link_rate_kbps * 8, 10);
* max_link_rate = max_link_rate_kbps / 8;
*/
return DIV_ROUND_DOWN_ULL(mul_u32_u32(max_link_rate_kbps * max_lanes,
ch_coding_efficiency),
1000000 * 8);
}
bool intel_dp_can_bigjoiner(struct intel_dp *intel_dp)
{
struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
@@ -658,7 +612,7 @@ static bool intel_dp_can_link_train_fallback_for_edp(struct intel_dp *intel_dp,
int mode_rate, max_rate;
mode_rate = intel_dp_link_required(fixed_mode->clock, 18);
max_rate = intel_dp_max_data_rate(link_rate, lane_count);
max_rate = drm_dp_max_dprx_data_rate(link_rate, lane_count);
if (mode_rate > max_rate)
return false;
@@ -1262,7 +1216,7 @@ intel_dp_mode_valid(struct drm_connector *_connector,
max_link_clock = intel_dp_max_link_rate(intel_dp);
max_lanes = intel_dp_max_lane_count(intel_dp);
max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes);
max_rate = drm_dp_max_dprx_data_rate(max_link_clock, max_lanes);
mode_rate = intel_dp_link_required(target_clock,
intel_dp_mode_min_output_bpp(connector, mode));
@@ -1612,8 +1566,8 @@ intel_dp_compute_link_config_wide(struct intel_dp *intel_dp,
for (lane_count = limits->min_lane_count;
lane_count <= limits->max_lane_count;
lane_count <<= 1) {
link_avail = intel_dp_max_data_rate(link_rate,
lane_count);
link_avail = drm_dp_max_dprx_data_rate(link_rate,
lane_count);
if (mode_rate <= link_avail) {
pipe_config->lane_count = lane_count;
@@ -2467,8 +2421,8 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
"DP link rate required %i available %i\n",
intel_dp_link_required(adjusted_mode->crtc_clock,
to_bpp_int_roundup(pipe_config->dsc.compressed_bpp_x16)),
intel_dp_max_data_rate(pipe_config->port_clock,
pipe_config->lane_count));
drm_dp_max_dprx_data_rate(pipe_config->port_clock,
pipe_config->lane_count));
} else {
drm_dbg_kms(&i915->drm, "DP lane count %d clock %d bpp %d\n",
pipe_config->lane_count, pipe_config->port_clock,
@@ -2478,8 +2432,8 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
"DP link rate required %i available %i\n",
intel_dp_link_required(adjusted_mode->crtc_clock,
pipe_config->pipe_bpp),
intel_dp_max_data_rate(pipe_config->port_clock,
pipe_config->lane_count));
drm_dp_max_dprx_data_rate(pipe_config->port_clock,
pipe_config->lane_count));
}
return 0;
}

1
drivers/gpu/drm/i915/display/intel_dp.h
View File

@@ -111,7 +111,6 @@ bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp);
int intel_dp_link_required(int pixel_clock, int bpp);
int intel_dp_effective_data_rate(int pixel_clock, int bpp_x16,
int bw_overhead);
int intel_dp_max_data_rate(int max_link_rate, int max_lanes);
bool intel_dp_can_bigjoiner(struct intel_dp *intel_dp);
bool intel_dp_needs_vsc_sdp(const struct intel_crtc_state *crtc_state,
const struct drm_connector_state *conn_state);

2
drivers/gpu/drm/i915/display/intel_dp_mst.c
View File

@@ -1299,7 +1299,7 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
max_link_clock = intel_dp_max_link_rate(intel_dp);
max_lanes = intel_dp_max_lane_count(intel_dp);
max_rate = intel_dp_max_data_rate(max_link_clock, max_lanes);
max_rate = drm_dp_max_dprx_data_rate(max_link_clock, max_lanes);
mode_rate = intel_dp_link_required(mode->clock, min_bpp);
ret = drm_modeset_lock(&mgr->base.lock, ctx);