From a9b14af999b058ee9371d3d8fa02245339da7302 Mon Sep 17 00:00:00 2001 From: Mitul Golani Date: Mon, 20 Jan 2025 22:52:08 +0530 Subject: [PATCH] drm/i915/dsc: Check if vblank is sufficient for dsc prefill High refresh rate panels which may have small line times and vblank sizes, Check if vblank size 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.[Ankit] - 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] --v4: - Improvise hscale and vscale calculation. [Ankit] - Use appropriate name for number of scaler users. [Ankit] - Update commit message and rebase. - Add linetime and cdclk prefill adjustment calculation. [Ankit] --v5: - Update bspec link in trailer. [Ankit] - Correct hscale, vscale datatype. [Ankit] - Use intel_crtc_compute_min_cdclk. [Ankit] --v6: - Use cdclk_state->logical.cdclk instead of intel_crtc_compute_min_cdclk. [Ankit] --v7: - Fix linetime calculation. [Ankit] - Reduce redandancy use of variables. [Ankit] - Fix typos. [Ankit] - Update calculation for precision. [Ankit] --v8: - Initialise variable to return garbage later. [Ankit] - Initialise few variables to use at local loop, where it is used. [Ankit] Bspec: 70151 Signed-off-by: Mitul Golani Reviewed-by: Ankit Nautiyal Signed-off-by: Ankit Nautiyal Link: https://patchwork.freedesktop.org/patch/msgid/20250120172209.188488-8-mitulkumar.ajitkumar.golani@intel.com --- drivers/gpu/drm/i915/display/skl_watermark.c | 33 +++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c index a2580112b50bc..45fe4aaeb450e 100644 --- a/drivers/gpu/drm/i915/display/skl_watermark.c +++ b/drivers/gpu/drm/i915/display/skl_watermark.c @@ -2310,6 +2310,37 @@ cdclk_prefill_adjustment(const struct intel_crtc_state *crtc_state) 2 * cdclk_state->logical.cdclk)); } +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 linetime = DIV_ROUND_UP(1000 * crtc_state->hw.adjusted_mode.htotal, + crtc_state->hw.adjusted_mode.clock); + int num_scaler_users = hweight32(scaler_state->scaler_users); + int chroma_downscaling_factor = + crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ? 2 : 1; + u32 dsc_prefill_latency = 0; + + if (!crtc_state->dsc.compression_enable || !num_scaler_users) + return dsc_prefill_latency; + + dsc_prefill_latency = DIV_ROUND_UP(15 * linetime * chroma_downscaling_factor, 10); + + for (int i = 0; i < num_scaler_users; i++) { + u64 hscale_k, vscale_k; + + hscale_k = max(1000, mul_u32_u32(scaler_state->scalers[i].hscale, 1000) >> 16); + vscale_k = max(1000, mul_u32_u32(scaler_state->scalers[i].vscale, 1000) >> 16); + dsc_prefill_latency = DIV_ROUND_UP_ULL(dsc_prefill_latency * hscale_k * vscale_k, + 1000000); + } + + dsc_prefill_latency *= cdclk_prefill_adjustment(crtc_state); + + return intel_usecs_to_scanlines(&crtc_state->hw.adjusted_mode, dsc_prefill_latency); +} + static int scaler_prefill_latency(const struct intel_crtc_state *crtc_state) { @@ -2349,10 +2380,10 @@ skl_is_vblank_too_short(const struct intel_crtc_state *crtc_state, const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode; - /* FIXME missing DSC pre-fill time */ 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; } -- 2.47.2