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author | Paulo Zanoni <paulo.r.zanoni@intel.com> | 2016-09-22 23:00:32 +0200 |
---|---|---|
committer | Jani Nikula <jani.nikula@intel.com> | 2016-10-10 15:06:39 +0200 |
commit | cf6c525a31fac11b0775b8c06c00a508c6356d9b (patch) | |
tree | 5bdb09fb2f2d27e9b653c43dbb412c0227582b81 /drivers/gpu | |
parent | drm/i915/gen9: minimum scanlines for Y tile is not always 4 (diff) | |
download | linux-cf6c525a31fac11b0775b8c06c00a508c6356d9b.tar.xz linux-cf6c525a31fac11b0775b8c06c00a508c6356d9b.zip |
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 <tvrtko.ursulin@intel.com>
Reviewed-by: Lyude <cpaul@redhat.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
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 <jani.nikula@intel.com>
Diffstat (limited to 'drivers/gpu')
-rw-r--r-- | drivers/gpu/drm/i915/intel_pm.c | 39 |
1 files changed, 15 insertions, 24 deletions
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 32ce9365d763..2f2ced7c6921 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) { |