[Qemu-devel] [PATCH] net: cadence_gem: clear RX control descriptor

[Ramon Fried <rfried.dev@gmail.com>]

The RX ring descriptors control field is used for setting
SOF and EOF (start of frame and end of frame).
The SOF and EOF weren't cleared from the previous descriptors,
causing inconsistencies in ring buffer.
Fix that by clearing the control field of every descriptors we're
processing.

Signed-off-by: Ramon Fried <rfried.dev@gmail.com>
---
 hw/net/cadence_gem.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index ecee22525c..d83a82bdb0 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -406,6 +406,11 @@ static inline void rx_desc_set_sof(uint32_t *desc)
     desc[1] |= DESC_1_RX_SOF;
 }
 
+static inline void rx_desc_clear(uint32_t *desc)
+{
+    desc[1]  = 0;
+}
+
 static inline void rx_desc_set_eof(uint32_t *desc)
 {
     desc[1] |= DESC_1_RX_EOF;
@@ -994,6 +999,8 @@ static ssize_t gem_receive(NetClientState *nc, const uint8_t *buf, size_t size)
         bytes_to_copy -= MIN(bytes_to_copy, rxbufsize);
 
         /* Update the descriptor.  */
+        rx_desc_clear(s->rx_desc[q]);
+
         if (first_desc) {
             rx_desc_set_sof(s->rx_desc[q]);
             first_desc = false;
-- 
2.21.0