[Mesa-dev] [PATCH 08/17] intel/isl/gen7: Allow msaa with signed integer formats

[Topi Pohjolainen]

These formats are already allowed by the i965 GL driver, and the
feature seems to work just fine.

There are tests for multisampled rendering in piglit:
tests/spec/ext_framebuffer_multisample which can be patched to
try 16I/32I in addition to GL_RGBA8I.
IvyBridge passed all tests with all sample numbers.

Signed-off-by: Topi Pohjolainen <topi.pohjolainen at intel.com>
---
 src/intel/isl/isl_gen7.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/intel/isl/isl_gen7.c b/src/intel/isl/isl_gen7.c
index 4c5edb4b93..ab47a7f622 100644
--- a/src/intel/isl/isl_gen7.c
+++ b/src/intel/isl/isl_gen7.c
@@ -76,9 +76,10 @@ isl_gen7_choose_msaa_layout(const struct isl_device *dev,
     * Note that the above SINT restrictions apply only to *MSRTs* (that is,
     * *multisampled* render targets). The restrictions seem to permit an MCS
     * if the render target is singlesampled.
+    *
+    * Moreover, empirically it looks that hardware can render multisampled
+    * surfaces with RGBA8I, RGBA16I and RGBA32I.
     */
-   if (isl_format_has_sint_channel(info->format))
-      return false;
 
    /* More obvious restrictions */
    if (isl_surf_usage_is_display(info->usage))
-- 
2.11.0