[PATCH v4 11/14] dp8393x: Clear descriptor in_use field to release packet

[Finn Thain]

When the SONIC receives a packet into the last available descriptor, it
retains ownership of that descriptor for as long as necessary.

Section 3.4.7 of the datasheet says,

    When the system appends more descriptors, the SONIC releases ownership
    of the descriptor after writing 0000h to the RXpkt.in_use field.

The packet can now be processed by the host, so raise a PKTRX interrupt,
just like the normal case.

Signed-off-by: Finn Thain <address@hidden>
Tested-by: Laurent Vivier <address@hidden>
---
Changed since v2:
 - Assert PKTRX interrupt when releasing withheld packet.
---
 hw/net/dp8393x.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index 13513986f0..99c5dad7c4 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -809,7 +809,17 @@ static ssize_t dp8393x_receive(NetClientState *nc, const 
uint8_t * buf,
             return -1;
         }
         /* Link has been updated by host */
+
+        /* Clear in_use */
+        size = sizeof(uint16_t) * width;
+        address = dp8393x_crda(s) + sizeof(uint16_t) * 6 * width;
+        dp8393x_put(s, width, 0, 0);
+        address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
+                         (uint8_t *)s->data, size, 1);
+
+        /* Move to next descriptor */
         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
+        s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
     }
 
     /* Save current position */
-- 
2.24.1