From 04d5d5df9df79f9045e76404775fc8a084aac23d Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Tue, 1 Jun 2021 07:21:07 +0300 Subject: drm/tegra: dc: Support memory bandwidth management Display controller (DC) performs isochronous memory transfers, and thus, has a requirement for a minimum memory bandwidth that shall be fulfilled, otherwise framebuffer data can't be fetched fast enough and this results in a DC's data-FIFO underflow that follows by a visual corruption. The Memory Controller drivers provide facility for memory bandwidth management via interconnect API. Let's wire up the interconnect API support to the DC driver in order to fix the distorted display output on T30 Ouya, T124 TK1 and other Tegra devices. Tested-by: Peter Geis # Ouya T30 Tested-by: Matt Merhar # Ouya T30 Tested-by: Nicolas Chauvet # PAZ00 T20 and TK1 T124 Signed-off-by: Dmitry Osipenko [treding@nvidia.com: unbreak Tegra186+ display support] Signed-off-by: Thierry Reding --- drivers/gpu/drm/tegra/plane.c | 117 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) (limited to 'drivers/gpu/drm/tegra/plane.c') diff --git a/drivers/gpu/drm/tegra/plane.c b/drivers/gpu/drm/tegra/plane.c index 2e65b4075ce6..e00ec3f40ec8 100644 --- a/drivers/gpu/drm/tegra/plane.c +++ b/drivers/gpu/drm/tegra/plane.c @@ -4,6 +4,7 @@ */ #include +#include #include #include @@ -64,6 +65,9 @@ tegra_plane_atomic_duplicate_state(struct drm_plane *plane) copy->reflect_x = state->reflect_x; copy->reflect_y = state->reflect_y; copy->opaque = state->opaque; + copy->total_peak_memory_bandwidth = state->total_peak_memory_bandwidth; + copy->peak_memory_bandwidth = state->peak_memory_bandwidth; + copy->avg_memory_bandwidth = state->avg_memory_bandwidth; for (i = 0; i < 2; i++) copy->blending[i] = state->blending[i]; @@ -244,6 +248,78 @@ void tegra_plane_cleanup_fb(struct drm_plane *plane, tegra_dc_unpin(dc, to_tegra_plane_state(state)); } +static int tegra_plane_calculate_memory_bandwidth(struct drm_plane_state *state) +{ + struct tegra_plane_state *tegra_state = to_tegra_plane_state(state); + unsigned int i, bpp, dst_w, dst_h, src_w, src_h, mul; + const struct tegra_dc_soc_info *soc; + const struct drm_format_info *fmt; + struct drm_crtc_state *crtc_state; + u64 avg_bandwidth, peak_bandwidth; + + if (!state->visible) + return 0; + + crtc_state = drm_atomic_get_new_crtc_state(state->state, state->crtc); + if (!crtc_state) + return -EINVAL; + + src_w = drm_rect_width(&state->src) >> 16; + src_h = drm_rect_height(&state->src) >> 16; + dst_w = drm_rect_width(&state->dst); + dst_h = drm_rect_height(&state->dst); + + fmt = state->fb->format; + soc = to_tegra_dc(state->crtc)->soc; + + /* + * Note that real memory bandwidth vary depending on format and + * memory layout, we are not taking that into account because small + * estimation error isn't important since bandwidth is rounded up + * anyway. + */ + for (i = 0, bpp = 0; i < fmt->num_planes; i++) { + unsigned int bpp_plane = fmt->cpp[i] * 8; + + /* + * Sub-sampling is relevant for chroma planes only and vertical + * readouts are not cached, hence only horizontal sub-sampling + * matters. + */ + if (i > 0) + bpp_plane /= fmt->hsub; + + bpp += bpp_plane; + } + + /* average bandwidth in kbytes/sec */ + avg_bandwidth = min(src_w, dst_w) * min(src_h, dst_h); + avg_bandwidth *= drm_mode_vrefresh(&crtc_state->adjusted_mode); + avg_bandwidth = DIV_ROUND_UP(avg_bandwidth * bpp, 8) + 999; + do_div(avg_bandwidth, 1000); + + /* mode.clock in kHz, peak bandwidth in kbytes/sec */ + peak_bandwidth = DIV_ROUND_UP(crtc_state->adjusted_mode.clock * bpp, 8); + + /* + * Tegra30/114 Memory Controller can't interleave DC memory requests + * for the tiled windows because DC uses 16-bytes atom, while DDR3 + * uses 32-bytes atom. Hence there is x2 memory overfetch for tiled + * framebuffer and DDR3 on these SoCs. + */ + if (soc->plane_tiled_memory_bandwidth_x2 && + tegra_state->tiling.mode == TEGRA_BO_TILING_MODE_TILED) + mul = 2; + else + mul = 1; + + /* ICC bandwidth in kbytes/sec */ + tegra_state->peak_memory_bandwidth = kBps_to_icc(peak_bandwidth) * mul; + tegra_state->avg_memory_bandwidth = kBps_to_icc(avg_bandwidth) * mul; + + return 0; +} + int tegra_plane_state_add(struct tegra_plane *plane, struct drm_plane_state *state) { @@ -262,6 +338,10 @@ int tegra_plane_state_add(struct tegra_plane *plane, if (err < 0) return err; + err = tegra_plane_calculate_memory_bandwidth(state); + if (err < 0) + return err; + tegra = to_dc_state(crtc_state); tegra->planes |= WIN_A_ACT_REQ << plane->index; @@ -646,3 +726,40 @@ int tegra_plane_setup_legacy_state(struct tegra_plane *tegra, return 0; } + +static const char * const tegra_plane_icc_names[TEGRA_DC_LEGACY_PLANES_NUM] = { + "wina", "winb", "winc", NULL, NULL, NULL, "cursor", +}; + +int tegra_plane_interconnect_init(struct tegra_plane *plane) +{ + const char *icc_name = tegra_plane_icc_names[plane->index]; + struct device *dev = plane->dc->dev; + struct tegra_dc *dc = plane->dc; + int err; + + if (WARN_ON(plane->index >= TEGRA_DC_LEGACY_PLANES_NUM) || + WARN_ON(!tegra_plane_icc_names[plane->index])) + return -EINVAL; + + plane->icc_mem = devm_of_icc_get(dev, icc_name); + err = PTR_ERR_OR_ZERO(plane->icc_mem); + if (err) { + dev_err_probe(dev, err, "failed to get %s interconnect\n", + icc_name); + return err; + } + + /* plane B on T20/30 has a dedicated memory client for a 6-tap vertical filter */ + if (plane->index == 1 && dc->soc->has_win_b_vfilter_mem_client) { + plane->icc_mem_vfilter = devm_of_icc_get(dev, "winb-vfilter"); + err = PTR_ERR_OR_ZERO(plane->icc_mem_vfilter); + if (err) { + dev_err_probe(dev, err, "failed to get %s interconnect\n", + "winb-vfilter"); + return err; + } + } + + return 0; +} -- cgit v1.2.3