diff mbox

[PULL,04/18] cadence_gem: Set the last bit when wrap is set

Message ID 1467038710-24307-5-git-send-email-peter.maydell@linaro.org
State New
Headers show

Commit Message

Peter Maydell June 27, 2016, 2:44 p.m. UTC 
From: Alistair Francis <alistair.francis@xilinx.com>

The Cadence GEM data sheet says:
"Wrap - marks last descriptor in transmit buffer descriptor list. This
can be set for any buffer within the frame."
which seems to imply that when the wrap bit is set so is the last bit.

Previously if the wrap bit is set, but the last is not then QEMU will
enter an infinite loop.

Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
Reported-by: Li Qiang <liqiang6-s@360.cn>
Reported-by: P J P <ppandit@redhat.com>
Message-id: eb23f15c67989ea6a53609dc66568399dadf52a7.1466539342.git.alistair.francis@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/net/cadence_gem.c | 6 ++++++
 1 file changed, 6 insertions(+)
diff mbox

Patch

diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index e5f3c98..8a4be1e 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -274,6 +274,11 @@  static inline unsigned tx_desc_get_last(unsigned *desc)
     return (desc[1] & DESC_1_TX_LAST) ? 1 : 0;
 }
 
+static inline void tx_desc_set_last(unsigned *desc)
+{
+    desc[1] |= DESC_1_TX_LAST;
+}
+
 static inline unsigned tx_desc_get_length(unsigned *desc)
 {
     return desc[1] & DESC_1_LENGTH;
@@ -939,6 +944,7 @@  static void gem_transmit(CadenceGEMState *s)
 
         /* read next descriptor */
         if (tx_desc_get_wrap(desc)) {
+            tx_desc_set_last(desc);
             packet_desc_addr = s->regs[GEM_TXQBASE];
         } else {
             packet_desc_addr += 8;