Mesa (master): i965/gen7: Use WE_all mode when enabling channel masks for URB write.

[Paul Berry]

Module: Mesa
Branch: master
Commit: 76ba30800d08149386c0bc6a6c5efc50590d3048
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=76ba30800d08149386c0bc6a6c5efc50590d3048

Author: Paul Berry <stereotype441 at gmail.com>
Date:   Sat Mar 23 08:23:03 2013 -0700

i965/gen7: Use WE_all mode when enabling channel masks for URB write.

Gen7 adds mask bits to the message header for a URB write which allow
the write to apply only to certain channels.  We don't use this
functionality, so to ensure that the entire write always occurs, we
emit an OR instruction to set the mask bits.

With the advent of geometry shaders, URB writes won't just happen at
the end of a thread; they will happen in mid-thread too.  Thus, we can
no longer rely on channel 0 being enabled, so we need to emit the OR
instruction in WE_all mode to ensure that it is executed.

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/mesa/drivers/dri/i965/brw_eu_emit.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_eu_emit.c b/src/mesa/drivers/dri/i965/brw_eu_emit.c
index 992e784..2355626 100644
--- a/src/mesa/drivers/dri/i965/brw_eu_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_eu_emit.c
@@ -2184,6 +2184,7 @@ void brw_urb_WRITE(struct brw_compile *p,
       /* Enable Channel Masks in the URB_WRITE_HWORD message header */
       brw_push_insn_state(p);
       brw_set_access_mode(p, BRW_ALIGN_1);
+      brw_set_mask_control(p, BRW_MASK_DISABLE);
       brw_OR(p, retype(brw_vec1_reg(BRW_MESSAGE_REGISTER_FILE, msg_reg_nr, 5),
 		       BRW_REGISTER_TYPE_UD),
 	        retype(brw_vec1_grf(0, 5), BRW_REGISTER_TYPE_UD),