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author | Mahesh Kumar <mahesh1.kumar@intel.com> | 2016-12-01 18:49:37 +0300 |
---|---|---|
committer | Paulo Zanoni <paulo.r.zanoni@intel.com> | 2016-12-07 21:30:34 +0300 |
commit | b95320bdf2d891011da9c5ec85dcb114483856a6 (patch) | |
tree | 2578f72c9c83314a2fc9fc4fdcb319dfcfef82fe /drivers/gpu/drm/i915/intel_pm.c | |
parent | 4b7b2331885a1ab348178f3faf9dc6a4dccae01a (diff) | |
download | linux-b95320bdf2d891011da9c5ec85dcb114483856a6.tar.xz |
drm/i915/skl+: change WM calc to fixed point 16.16
This patch changes Watermak calculation to fixed point calculation.
Problem with current calculation is during plane_blocks_per_line
calculation we divide intermediate blocks with min_scanlines and
takes floor of the result because of integer operation.
hence we end-up assigning less blocks than required. Which leads to
flickers.
Changes since V1:
- Add fixed point data type as per Paulo's review
Changes since V2:
- use fixed_point instead of fp_16_16
Changes since V3:
- rebase
Changes since V4 (from Paulo):
- My original renaming suggestion was misunderstood, so implement it
- Simplify fixed_16_16_to_u32 implementation
- Fix indentation
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161201154940.24446-6-mahesh1.kumar@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/intel_pm.c')
-rw-r--r-- | drivers/gpu/drm/i915/intel_pm.c | 69 |
1 files changed, 40 insertions, 29 deletions
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 315a1b339257..9171431558a3 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3509,32 +3509,35 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate, * should allow pixel_rate up to ~2 GHz which seems sufficient since max * 2xcdclk is 1350 MHz and the pixel rate should never exceed that. */ -static uint32_t skl_wm_method1(uint32_t pixel_rate, uint8_t cpp, uint32_t latency) +static uint_fixed_16_16_t skl_wm_method1(uint32_t pixel_rate, uint8_t cpp, + uint32_t latency) { - uint32_t wm_intermediate_val, ret; + uint32_t wm_intermediate_val; + uint_fixed_16_16_t ret; if (latency == 0) - return UINT_MAX; - - wm_intermediate_val = latency * pixel_rate * cpp / 512; - ret = DIV_ROUND_UP(wm_intermediate_val, 1000); + return FP_16_16_MAX; + wm_intermediate_val = latency * pixel_rate * cpp; + ret = fixed_16_16_div_round_up_u64(wm_intermediate_val, 1000 * 512); return ret; } -static uint32_t skl_wm_method2(uint32_t pixel_rate, uint32_t pipe_htotal, - uint32_t latency, uint32_t plane_blocks_per_line) +static uint_fixed_16_16_t skl_wm_method2(uint32_t pixel_rate, + uint32_t pipe_htotal, + uint32_t latency, + uint_fixed_16_16_t plane_blocks_per_line) { - uint32_t ret; uint32_t wm_intermediate_val; + uint_fixed_16_16_t ret; if (latency == 0) - return UINT_MAX; + return FP_16_16_MAX; wm_intermediate_val = latency * pixel_rate; - ret = DIV_ROUND_UP(wm_intermediate_val, pipe_htotal * 1000) * - plane_blocks_per_line; - + wm_intermediate_val = DIV_ROUND_UP(wm_intermediate_val, + pipe_htotal * 1000); + ret = mul_u32_fixed_16_16(wm_intermediate_val, plane_blocks_per_line); return ret; } @@ -3574,14 +3577,17 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv, struct drm_plane_state *pstate = &intel_pstate->base; struct drm_framebuffer *fb = pstate->fb; uint32_t latency = dev_priv->wm.skl_latency[level]; - uint32_t method1, method2; - uint32_t plane_bytes_per_line, plane_blocks_per_line; + uint_fixed_16_16_t method1, method2; + uint_fixed_16_16_t plane_blocks_per_line; + uint_fixed_16_16_t selected_result; + uint32_t interm_pbpl; + uint32_t plane_bytes_per_line; uint32_t res_blocks, res_lines; - uint32_t selected_result; uint8_t cpp; uint32_t width = 0, height = 0; uint32_t plane_pixel_rate; - uint32_t y_tile_minimum, y_min_scanlines; + uint_fixed_16_16_t y_tile_minimum; + uint32_t y_min_scanlines; struct intel_atomic_state *state = to_intel_atomic_state(cstate->base.state); bool apply_memory_bw_wa = skl_needs_memory_bw_wa(state); @@ -3640,14 +3646,16 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv, plane_bytes_per_line = width * cpp; if (y_tiled) { + interm_pbpl = DIV_ROUND_UP(plane_bytes_per_line * + y_min_scanlines, 512); plane_blocks_per_line = - DIV_ROUND_UP(plane_bytes_per_line * y_min_scanlines, 512); - plane_blocks_per_line /= y_min_scanlines; + fixed_16_16_div_round_up(interm_pbpl, y_min_scanlines); } else if (x_tiled) { - plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512); + interm_pbpl = DIV_ROUND_UP(plane_bytes_per_line, 512); + plane_blocks_per_line = u32_to_fixed_16_16(interm_pbpl); } else { - plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512) - + 1; + interm_pbpl = DIV_ROUND_UP(plane_bytes_per_line, 512) + 1; + plane_blocks_per_line = u32_to_fixed_16_16(interm_pbpl); } method1 = skl_wm_method1(plane_pixel_rate, cpp, latency); @@ -3656,26 +3664,29 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv, latency, plane_blocks_per_line); - y_tile_minimum = plane_blocks_per_line * y_min_scanlines; + y_tile_minimum = mul_u32_fixed_16_16(y_min_scanlines, + plane_blocks_per_line); if (y_tiled) { - selected_result = max(method2, y_tile_minimum); + selected_result = max_fixed_16_16(method2, y_tile_minimum); } else { if ((cpp * cstate->base.adjusted_mode.crtc_htotal / 512 < 1) && (plane_bytes_per_line / 512 < 1)) selected_result = method2; - else if ((ddb_allocation / plane_blocks_per_line) >= 1) - selected_result = min(method1, method2); + else if ((ddb_allocation / + fixed_16_16_to_u32_round_up(plane_blocks_per_line)) >= 1) + selected_result = min_fixed_16_16(method1, method2); else selected_result = method1; } - res_blocks = selected_result + 1; - res_lines = DIV_ROUND_UP(selected_result, plane_blocks_per_line); + res_blocks = fixed_16_16_to_u32_round_up(selected_result) + 1; + res_lines = DIV_ROUND_UP(selected_result.val, + plane_blocks_per_line.val); if (level >= 1 && level <= 7) { if (y_tiled) { - res_blocks += y_tile_minimum; + res_blocks += fixed_16_16_to_u32_round_up(y_tile_minimum); res_lines += y_min_scanlines; } else { res_blocks++; |