On Mon, Aug 10, 2015 at 4:15 PM, Ben Widawsky <benjamin.widaw...@intel.com> wrote: > > The spec does say that the blitter is capable of transferring 64k scanlines > in a > single blit operation. Perhaps this was true, or is still true on some > operations, but for all commands that we use, we are restricted to 16b signed: > > For example, from the XY_SRC_COPY_CHROMA_BLT definition: > > Destination Y2 Coordinate (Bottom) > > 16 bit signed number. > > v2: Rebase; conflicts resolved with wiggle > > Signed-off-by: Ben Widawsky <b...@bwidawsk.net> > Reviewed-by: Neil Roberts <n...@linux.intel.com> > --- > src/mesa/drivers/dri/i965/intel_blit.c | 8 ++++++-- > src/mesa/drivers/dri/i965/intel_copy_image.c | 8 ++++++-- > 2 files changed, 12 insertions(+), 4 deletions(-) > > diff --git a/src/mesa/drivers/dri/i965/intel_blit.c > b/src/mesa/drivers/dri/i965/intel_blit.c > index 6d92580..4a76ba9 100644 > --- a/src/mesa/drivers/dri/i965/intel_blit.c > +++ b/src/mesa/drivers/dri/i965/intel_blit.c > @@ -298,11 +298,15 @@ intel_miptree_blit(struct brw_context *brw, > * The BLT engine is capable of transferring very large quantities of > * graphics data. Any graphics data read from and written to the > * destination is permitted to represent a number of pixels that > - * occupies up to 65,536 scan lines and up to 32,768 bytes per scan > line > - * at the destination. The maximum number of pixels that may be > + * occupies up to 65,536 [sic] scan lines and up to 32,768 bytes per > scan > + * line at the destination. The maximum number of pixels that may be > * represented per scan line’s worth of graphics data depends on the > * color depth. > * > + * XXX: The spec is likely incorrect. The number of scanlines is > represented > + * in the blit command as a 16b signed number, thus 32,767 as the max > number > + * of scanlines. > + * > * Furthermore, intelEmitCopyBlit (which is called below) uses a signed > * 16-bit integer to represent buffer pitch, so it can only handle buffer > * pitches < 32k. However, the pitch is measured in bytes for linear > buffers > diff --git a/src/mesa/drivers/dri/i965/intel_copy_image.c > b/src/mesa/drivers/dri/i965/intel_copy_image.c > index 3706704..c12decc 100644 > --- a/src/mesa/drivers/dri/i965/intel_copy_image.c > +++ b/src/mesa/drivers/dri/i965/intel_copy_image.c > @@ -53,11 +53,15 @@ copy_image_with_blitter(struct brw_context *brw, > * The BLT engine is capable of transferring very large quantities of > * graphics data. Any graphics data read from and written to the > * destination is permitted to represent a number of pixels that > - * occupies up to 65,536 scan lines and up to 32,768 bytes per scan > line > - * at the destination. The maximum number of pixels that may be > + * occupies up to 65,536 [sic] scan lines and up to 32,768 bytes per > scan > + * line at the destination. The maximum number of pixels that may be > * represented per scan line’s worth of graphics data depends on the > * color depth. > * > + * XXX: The spec is likely incorrect. The number of scanlines is > represented > + * in the blit command as a 16b signed number, thus 32,767 as the max > number > + * of scanlines. > + * > * Furthermore, intelEmitCopyBlit (which is called below) uses a signed > * 16-bit integer to represent buffer pitch, so it can only handle buffer > * pitches < 32k. > -- > 2.5.0 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev
Reviewed-by: Anuj Phogat <anuj.pho...@gmail.com> _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
