From cf6c525a31fac11b0775b8c06c00a508c6356d9b Mon Sep 17 00:00:00 2001 From: Paulo Zanoni Date: Thu, 22 Sep 2016 18:00:32 -0300 Subject: [PATCH] drm/i915/gen9: fix plane_blocks_per_line on watermarks calculations The confusing thing is that plane_blocks_per_line is listed as part of the method 2 calculation but is also used for other things. We calculated it in two different places and different ways: one inside skl_wm_method2() and the other inside skl_compute_plane_wm(). The skl_wm_method2() implementation is the one that matches the specification. With this patch we fix the skl_compute_plane_wm() calculation and just pass it as a parameter to skl_wm_method2(). We also take care to not modify the value of plane_bytes_per_line since we're going to rely on it having a correct value in later patches. This should affect the watermarks for Linear and Y-tiled. From my analysis, it looks like the two plane_blocks_per_line variables got out of sync on 0fda65680e92, but we can't really say that commit was a regression, it looks like just an incomplete fix. There's always the possibility that 0fda65680e92 matched our specification at that time, and then later the specification changed. v2: Try to add a "Fixes" tag (Maarten). Fixes: 0fda65680e92 ("drm/i915/skl: Update watermarks for Y tiling") Cc: stable@vger.kernel.org Cc: Tvrtko Ursulin Reviewed-by: Lyude Reviewed-by: Maarten Lankhorst Signed-off-by: Paulo Zanoni Link: http://patchwork.freedesktop.org/patch/msgid/1474578035-424-7-git-send-email-paulo.r.zanoni@intel.com (cherry picked from commit 7a1a8aed67e0a60772defe3f6499eb340da48634) Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_pm.c | 39 +++++++++++++++------------------------ 1 file changed, 15 insertions(+), 24 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 32ce936..2f2ced7 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3494,30 +3494,14 @@ static uint32_t skl_wm_method1(uint32_t pixel_rate, uint8_t cpp, uint32_t latenc } static uint32_t skl_wm_method2(uint32_t pixel_rate, uint32_t pipe_htotal, - uint32_t horiz_pixels, uint8_t cpp, - uint64_t tiling, uint32_t latency, - uint32_t y_min_scanlines) + uint32_t latency, uint32_t plane_blocks_per_line) { uint32_t ret; - uint32_t plane_bytes_per_line, plane_blocks_per_line; uint32_t wm_intermediate_val; if (latency == 0) return UINT_MAX; - plane_bytes_per_line = horiz_pixels * cpp; - - if (tiling == I915_FORMAT_MOD_Y_TILED || - tiling == I915_FORMAT_MOD_Yf_TILED) { - plane_bytes_per_line *= y_min_scanlines; - plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512); - plane_blocks_per_line /= y_min_scanlines; - } else if (tiling == DRM_FORMAT_MOD_NONE) { - plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512) + 1; - } else { - plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512); - } - wm_intermediate_val = latency * pixel_rate; ret = DIV_ROUND_UP(wm_intermediate_val, pipe_htotal * 1000) * plane_blocks_per_line; @@ -3606,17 +3590,24 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv, y_min_scanlines = 4; } + plane_bytes_per_line = width * cpp; + if (fb->modifier[0] == I915_FORMAT_MOD_Y_TILED || + fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED) { + plane_blocks_per_line = + DIV_ROUND_UP(plane_bytes_per_line * y_min_scanlines, 512); + plane_blocks_per_line /= y_min_scanlines; + } else if (fb->modifier[0] == DRM_FORMAT_MOD_NONE) { + plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512) + + 1; + } else { + plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512); + } + method1 = skl_wm_method1(plane_pixel_rate, cpp, latency); method2 = skl_wm_method2(plane_pixel_rate, cstate->base.adjusted_mode.crtc_htotal, - width, - cpp, - fb->modifier[0], latency, - y_min_scanlines); - - plane_bytes_per_line = width * cpp; - plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512); + plane_blocks_per_line); if (fb->modifier[0] == I915_FORMAT_MOD_Y_TILED || fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED) { -- 2.7.4