[Mesa-dev] [PATCH 1/4] i965: Fix issues with number of VS URB entries on Cherryview/Broxton.

[Kenneth Graunke]

Cherryview/Broxton annoyingly have a minimum number of VS URB entries
of 34, which is not a multiple of 8.  When the VS size is less than 9,
the number of VS entries has to be a multiple of 8.

Notably, BLORP programmed the minimum number of VS URB entries (34), with
a size of 1 (less than 9), which is invalid.

It seemed like this could be a problem in the regular URB code as well,
so I went ahead and updated that to be safe.

Cc: "12.0" <mesa-stable at lists.freedesktop.org>
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/mesa/drivers/dri/i965/gen7_blorp.c | 5 +++--
 src/mesa/drivers/dri/i965/gen7_urb.c   | 2 ++
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/gen7_blorp.c b/src/mesa/drivers/dri/i965/gen7_blorp.c
index 270fe57..235f0b5 100644
--- a/src/mesa/drivers/dri/i965/gen7_blorp.c
+++ b/src/mesa/drivers/dri/i965/gen7_blorp.c
@@ -67,8 +67,9 @@ gen7_blorp_emit_urb_config(struct brw_context *brw)
       push_constant_bytes / chunk_size_bytes;
    const unsigned vs_size = 1;
    const unsigned vs_start = push_constant_chunks;
+   const unsigned min_vs_entries = ALIGN(brw->urb.min_vs_entries, 8);
    const unsigned vs_chunks =
-      DIV_ROUND_UP(brw->urb.min_vs_entries * vs_size * 64, chunk_size_bytes);
+      DIV_ROUND_UP(min_vs_entries * vs_size * 64, chunk_size_bytes);
 
    if (gen7_blorp_skip_urb_config(brw))
       return;
@@ -83,7 +84,7 @@ gen7_blorp_emit_urb_config(struct brw_context *brw)
                                  urb_size / 2 /* fs_size */);
 
    gen7_emit_urb_state(brw,
-                       brw->urb.min_vs_entries /* num_vs_entries */,
+                       min_vs_entries /* num_vs_entries */,
                        vs_size,
                        vs_start,
                        0 /* num_hs_entries */,
diff --git a/src/mesa/drivers/dri/i965/gen7_urb.c b/src/mesa/drivers/dri/i965/gen7_urb.c
index a412a42..387ed2e 100644
--- a/src/mesa/drivers/dri/i965/gen7_urb.c
+++ b/src/mesa/drivers/dri/i965/gen7_urb.c
@@ -234,6 +234,8 @@ gen7_upload_urb(struct brw_context *brw)
     */
    unsigned vs_min_entries =
       tess_present && brw->gen == 8 ? 192 : brw->urb.min_vs_entries;
+   /* Min VS Entries isn't a multiple of 8 on Cherryview/Broxton; round up */
+   vs_min_entries = ALIGN(vs_min_entries, vs_granularity);
 
    unsigned vs_chunks =
       DIV_ROUND_UP(vs_min_entries * vs_entry_size_bytes, chunk_size_bytes);
-- 
2.8.3