Mesa (master): radeonsi: document a CP DMA bug that doesn' t need a workaround yet

[Marek Olšák]

Module: Mesa
Branch: master
Commit: 77014a0ad36acf11b704ab20456259831a102308
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=77014a0ad36acf11b704ab20456259831a102308

Author: Marek Olšák <marek.olsak at amd.com>
Date:   Wed Nov 30 01:38:23 2016 +0100

radeonsi: document a CP DMA bug that doesn't need a workaround yet

This one is easy to miss, because it's not documented in any internal doc.

Reviewed-by: Nicolai Hähnle <nicolai.haehnle at amd.com>

---

 src/amd/common/sid.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/amd/common/sid.h b/src/amd/common/sid.h
index 7f598ca..3b3983f 100644
--- a/src/amd/common/sid.h
+++ b/src/amd/common/sid.h
@@ -151,7 +151,11 @@
 #define PKT3_COND_WRITE                        0x45
 #define PKT3_EVENT_WRITE                       0x46
 #define PKT3_EVENT_WRITE_EOP                   0x47
-#define PKT3_EVENT_WRITE_EOS                   0x48
+/* CP DMA bug: Any use of CP_DMA.DST_SEL=TC must be avoided when EOS packets
+ * are used. Use DST_SEL=MC instead. For prefetch, use SRC_SEL=TC and
+ * DST_SEL=MC. Only CIK chips are affected.
+ */
+/*#define PKT3_EVENT_WRITE_EOS                   0x48*/ /* fix CP DMA before uncommenting */
 #define PKT3_ONE_REG_WRITE                     0x57 /* not on CIK */
 #define PKT3_ACQUIRE_MEM                       0x58 /* new for CIK */
 #define PKT3_SET_CONFIG_REG                    0x68