On Thu, Feb 21, 2013 at 02:45:26PM +0000, Chris Wilson wrote: > We trim the fb to fit the CRTC by computing the offset of that CRTC to > its nearest tile_row origin. This allows us to use framebuffers that are > larger than the CRTC limits without additional work. > > However, we failed to compute the offset for a linear framebuffer > correctly as we treated its x-advance in whole tiles (instead of the > linear increment expected), leaving the CRTC misaligned with its > contents. > > Fixes regression from commit c2c75131244507c93f812862fdbd4f3a37139401 > Author: Daniel Vetter <daniel.vetter at ffwll.ch> > Date: Thu Jul 5 12:17:30 2012 +0200 > > drm/i915: adjust framebuffer base address on gen4+ > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61152 > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk> > Cc: Daniel Vetter <daniel.vetter at ffwll.ch> > Cc: stable at vger.kernel.org > --- > drivers/gpu/drm/i915/intel_display.c | 14 +++++++++----- > drivers/gpu/drm/i915/intel_drv.h | 3 ++- > drivers/gpu/drm/i915/intel_sprite.c | 6 ++++-- > 3 files changed, 15 insertions(+), 8 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index a3ca9a8..2a46f08 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -1906,18 +1906,20 @@ void intel_unpin_fb_obj(struct drm_i915_gem_object *obj) > > /* Computes the linear offset to the base tile and adjusts x, y. bytes per pixel > * is assumed to be a power-of-two. */ > -unsigned long intel_gen4_compute_offset_xtiled(int *x, int *y, > +unsigned long intel_gen4_compute_planar_offset(int *x, int *y, > + unsigned int tiling_mode, > unsigned int bpp, > unsigned int pitch) > { > - int tile_rows, tiles; > + int tile_rows, tiles, tile_size; > > tile_rows = *y / 8; > *y %= 8; > tiles = *x / (512/bpp); > *x %= 512/bpp; > > - return tile_rows * pitch * 8 + tiles * 4096; > + tile_size = tiling_mode != I915_TILING_NONE ? 4096 : 512; > + return (tile_rows * pitch * 8 + tiles * tile_size) & -4096; This doesn't seem to work as intended. Eg. plug in x=128, y=0, bpp=4, pitch=1024 and you get x=0,y=0,off=0 out. Well I suppose it works when we actually have the LINOFF register since we compute the value using the original x/y values, and the subtract the result from this computation. But that sort of behaviour seems a bit fragile. And in any case, this won't work on HSW where we use the adjusted x/y offsets even w/ linear surfaces. -- Ville Syrj?l? Intel OTC
