Follow the algorithm given in the National Semiconductor DP83932C
datasheet in section 3.4.7:
At the next reception, the SONIC re-reads the last RXpkt.link field,
and updates its CRDA register to point to the next descriptor.
The chip is designed to allow the host to provide a new list of
descriptors in this way.
Signed-off-by: Finn Thain <fth...@telegraphics.com.au>
Tested-by: Laurent Vivier <laur...@vivier.eu>
---
Changed since v1:
- Update CRDA register from LLFA register after EOL is cleared.
---
hw/net/dp8393x.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/hw/net/dp8393x.c b/hw/net/dp8393x.c
index ece72cbf42..249be403af 100644
--- a/hw/net/dp8393x.c
+++ b/hw/net/dp8393x.c
@@ -784,12 +784,13 @@ static ssize_t dp8393x_receive(NetClientState *nc, const
uint8_t * buf,
address = dp8393x_crda(s) + sizeof(uint16_t) * 5 * width;
address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
(uint8_t *)s->data, size, 0);
- if (dp8393x_get(s, width, 0) & SONIC_DESC_EOL) {
+ s->regs[SONIC_LLFA] = dp8393x_get(s, width, 0);
+ if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
/* Still EOL ; stop reception */
return -1;
- } else {
- s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
}
+ /* Link has been updated by host */
+ s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
}
/* Save current position */
@@ -837,7 +838,7 @@ static ssize_t dp8393x_receive(NetClientState *nc, const
uint8_t * buf,
address_space_rw(&s->as, dp8393x_crda(s),
MEMTXATTRS_UNSPECIFIED, (uint8_t *)s->data, size, 1);
- /* Move to next descriptor */
+ /* Check link field */
size = sizeof(uint16_t) * width;
address_space_rw(&s->as, dp8393x_crda(s) + sizeof(uint16_t) * 5 * width,
MEMTXATTRS_UNSPECIFIED, (uint8_t *)s->data, size, 0);
@@ -852,6 +853,8 @@ static ssize_t dp8393x_receive(NetClientState *nc, const
uint8_t * buf,
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;
s->regs[SONIC_RSC] = (s->regs[SONIC_RSC] & 0xff00) |
(((s->regs[SONIC_RSC] & 0x00ff) + 1) & 0x00ff);
--
2.24.1
