From a9da512b3ed73045253afd778e40d4298f42905b Mon Sep 17 00:00:00 2001 From: Paulo Zanoni Date: Mon, 14 Sep 2015 15:19:57 -0300 Subject: drm/i915: avoid the last 8mb of stolen on BDW/SKL MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The FBC hardware for these platforms doesn't have access to the bios_reserved range, so it always assumes the maximum (8mb) is used. So avoid this range while allocating. This solves a bunch of FIFO underruns that happen if you end up putting the CFB in that memory range. On my machine, with 32mb of stolen, I need a 2560x1440 mode for that. Testcase: igt/kms_frontbuffer_tracking/fbc-* (given the right setup) Signed-off-by: Paulo Zanoni Reviewed-by: Ville Syrjälä Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_fbc.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/i915/intel_fbc.c') diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c index db3809134a29..6f3c2ea75dd8 100644 --- a/drivers/gpu/drm/i915/intel_fbc.c +++ b/drivers/gpu/drm/i915/intel_fbc.c @@ -551,6 +551,16 @@ static int find_compression_threshold(struct drm_i915_private *dev_priv, { int compression_threshold = 1; int ret; + u64 end; + + /* The FBC hardware for BDW/SKL doesn't have access to the stolen + * reserved range size, so it always assumes the maximum (8mb) is used. + * If we enable FBC using a CFB on that memory range we'll get FIFO + * underruns, even if that range is not reserved by the BIOS. */ + if (IS_BROADWELL(dev_priv) || IS_SKYLAKE(dev_priv)) + end = dev_priv->gtt.stolen_size - 8 * 1024 * 1024; + else + end = dev_priv->gtt.stolen_usable_size; /* HACK: This code depends on what we will do in *_enable_fbc. If that * code changes, this code needs to change as well. @@ -560,7 +570,8 @@ static int find_compression_threshold(struct drm_i915_private *dev_priv, */ /* Try to over-allocate to reduce reallocations and fragmentation. */ - ret = i915_gem_stolen_insert_node(dev_priv, node, size <<= 1, 4096); + ret = i915_gem_stolen_insert_node_in_range(dev_priv, node, size <<= 1, + 4096, 0, end); if (ret == 0) return compression_threshold; @@ -570,7 +581,8 @@ again: (fb_cpp == 2 && compression_threshold == 2)) return 0; - ret = i915_gem_stolen_insert_node(dev_priv, node, size >>= 1, 4096); + ret = i915_gem_stolen_insert_node_in_range(dev_priv, node, size >>= 1, + 4096, 0, end); if (ret && INTEL_INFO(dev_priv)->gen <= 4) { return 0; } else if (ret) { -- cgit v1.2.3