Check if vblank is sufficient for dsc prefill latency. --v2: - Consider chroma downscaling factor in latency calculation. [Ankit] - Replace with appropriate function name.
--v3: - Remove FIXME tag.[Ankit] - Replace Ycbcr444 to Ycbcr420.[Anit] - Correct precision. [Ankit] - Use some local valiables like linetime_factor and latency to adjust precision. - Declare latency to 0 initially to avoid returning any garbage values. - Account for second scaler downscaling factor as well. [Ankit] Signed-off-by: Mitul Golani <[email protected]> --- drivers/gpu/drm/i915/display/skl_watermark.c | 37 ++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c index fe91854e456c..d275ec687748 100644 --- a/drivers/gpu/drm/i915/display/skl_watermark.c +++ b/drivers/gpu/drm/i915/display/skl_watermark.c @@ -2292,6 +2292,42 @@ static int icl_build_plane_wm(struct intel_crtc_state *crtc_state, return 0; } +static int +dsc_prefill_latency(const struct intel_crtc_state *crtc_state) +{ + const struct intel_crtc_scaler_state *scaler_state = + &crtc_state->scaler_state; + int latency = 0; + int count = hweight32(scaler_state->scaler_users); + long long hscale_k[2] = {1, 1}; + long long vscale_k[2] = {1, 1}; + + if (!crtc_state->dsc.compression_enable) + return latency; + + for (int i = 0; i < count; i++) { + hscale_k[i] = mul_u32_u32(scaler_state->scalers[i].hscale, 1000) >> 16; + vscale_k[i] = mul_u32_u32(scaler_state->scalers[i].vscale, 1000) >> 16; + } + + if (count) { + int chroma_downscaling_factor = + crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ? 2 : 1; + long long total_scaling_factor; + int linetime_factor = DIV_ROUND_UP(15 * crtc_state->linetime, 10); + + total_scaling_factor = DIV_ROUND_UP_ULL(hscale_k[0] * vscale_k[0], 1000000); + + if (count > 1) + total_scaling_factor *= DIV_ROUND_UP_ULL(hscale_k[1] * vscale_k[1], + 1000000); + + latency = total_scaling_factor * linetime_factor * chroma_downscaling_factor; + } + + return latency; +} + static int scaler_prefill_latency(const struct intel_crtc_state *crtc_state) { @@ -2333,6 +2369,7 @@ skl_is_vblank_too_short(const struct intel_crtc_state *crtc_state, return crtc_state->framestart_delay + intel_usecs_to_scanlines(adjusted_mode, latency) + scaler_prefill_latency(crtc_state) + + dsc_prefill_latency(crtc_state) + wm0_lines > adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vblank_start; } -- 2.46.0
