diff options
| -rw-r--r-- | os/io/platforms/AT91SAM7X/mac_lld.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/os/io/platforms/AT91SAM7X/mac_lld.c b/os/io/platforms/AT91SAM7X/mac_lld.c index 55874bab8..ebaed4e9c 100644 --- a/os/io/platforms/AT91SAM7X/mac_lld.c +++ b/os/io/platforms/AT91SAM7X/mac_lld.c @@ -282,7 +282,65 @@ uint8_t *mac_lld_get_transmit_buffer(MACTransmitDescriptor *tdp) { */
MACReceiveDescriptor *max_lld_get_receive_descriptor(MACDriver *macp,
size_t *szp) {
+ unsigned n;
+ MACReceiveDescriptor *rdp;
+ n = EMAC_RECEIVE_BUFFERS;
+
+ /*
+ * Skips unused buffers, if any.
+ */
+skip:
+ while ((n > 0) && !(rxptr->w1 & W1_R_OWNERSHIP)) {
+ if (++rxptr >= &rd[EMAC_RECEIVE_BUFFERS])
+ rxptr = rd;
+ n--;
+ }
+
+ /*
+ * Skips fragments, if any, cleaning them up.
+ */
+ while ((n > 0) && (rxptr->w1 & W1_R_OWNERSHIP) &&
+ !(rxptr->w2 & W2_R_FRAME_START)) {
+ rxptr->w1 &= ~W1_R_OWNERSHIP;
+ if (++rxptr >= &rd[EMAC_RECEIVE_BUFFERS])
+ rxptr = rd;
+ n--;
+ }
+
+ /*
+ * Now compute the total frame size skipping eventual incomplete frames
+ * or holes... + */
+restart:
+ rdp = rxptr;
+ while (n > 0) {
+ if (!(rxptr->w1 & W1_R_OWNERSHIP))
+ goto skip; /* Empty buffer for some reason... */
+
+ /*
+ * End Of Frame found.
+ */
+ if (rxptr->w2 & W2_R_FRAME_END) {
+ *szp = rxptr->w2 & W2_T_LENGTH_MASK;
+ return rdp;
+ }
+
+ if ((rdp != rxptr) && (rxptr->w2 & W2_R_FRAME_START)) {
+ /* Found another start... cleaning up the incomplete frame.*/
+ do {
+ rdp->w1 &= ~W1_R_OWNERSHIP;
+ if (++rdp >= &rd[EMAC_RECEIVE_BUFFERS])
+ rdp = rd;
+ }
+ while (rdp != rxptr);
+ goto restart; /* Another start buffer for some reason... */
+ }
+ + if (++rxptr >= &rd[EMAC_RECEIVE_BUFFERS])
+ rxptr = rd;
+ n--;
+ }
return NULL;
}
@@ -297,6 +355,14 @@ MACReceiveDescriptor *max_lld_get_receive_descriptor(MACDriver *macp, void mac_lld_release_receive_descriptor(MACDriver *macp,
MACReceiveDescriptor *rdp) {
+ unsigned n = EMAC_RECEIVE_BUFFERS;
+ do {
+ rdp->w1 &= ~W1_R_OWNERSHIP;
+ if (++rdp >= &rd[EMAC_RECEIVE_BUFFERS])
+ rdp = rd;
+ n--;
+ }
+ while ((n > 0) || !(rxptr->w2 & W2_R_FRAME_END));
}
/**
|