i965/eu: Fix Gen7+ DP scratch message size calculation on Gen7.

Gen7 hardware expects the block size field in the message descriptor
to be the number of registers minus one instead of the log2 of the
number of registers.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

diff --git a/src/mesa/drivers/dri/i965/brw_eu_emit.c b/src/mesa/drivers/dri/i965/brw_eu_emit.c
index 9dba818b1b30ab7b46be70cce957656d28e3ff27..6cbe673e94dc28d8662764e41c59b5478cd10ccf 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_eu_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_eu_emit.c
@@ -817,13 +817,16 @@ gen7_set_dp_scratch_message(struct brw_codegen *p,
    const struct brw_device_info *devinfo = p->devinfo;
    assert(num_regs == 1 || num_regs == 2 || num_regs == 4 ||
           (devinfo->gen >= 8 && num_regs == 8));
+   const unsigned block_size = (devinfo->gen >= 8 ? _mesa_logbase2(num_regs) :
+                                num_regs - 1);
+
    brw_set_message_descriptor(p, inst, GEN7_SFID_DATAPORT_DATA_CACHE,
                               mlen, rlen, header_present, false);
    brw_inst_set_dp_category(devinfo, inst, 1); /* Scratch Block Read/Write msgs */
    brw_inst_set_scratch_read_write(devinfo, inst, write);
    brw_inst_set_scratch_type(devinfo, inst, dword);
    brw_inst_set_scratch_invalidate_after_read(devinfo, inst, invalidate_after_read);
-   brw_inst_set_scratch_block_size(devinfo, inst, ffs(num_regs) - 1);
+   brw_inst_set_scratch_block_size(devinfo, inst, block_size);
    brw_inst_set_scratch_addr_offset(devinfo, inst, addr_offset);
 }