dp8393x: Update LLFA and CRDA registers from rx descriptor

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 <fthain@telegraphics.com.au>
Tested-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Finn Thain 2020-01-29 20:27:49 +11:00 committed by Jason Wang
parent 9e3cd456d8
commit 5b0c98fcb7
1 changed files with 7 additions and 4 deletions

View File

@ -786,12 +786,13 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
address = dp8393x_crda(s) + sizeof(uint16_t) * 5 * width;
address_space_read(&s->as, address, MEMTXATTRS_UNSPECIFIED,
s->data, size);
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 */
@ -840,7 +841,7 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
MEMTXATTRS_UNSPECIFIED,
s->data, size);
/* Move to next descriptor */
/* Check link field */
size = sizeof(uint16_t) * width;
address_space_read(&s->as,
dp8393x_crda(s) + sizeof(uint16_t) * 5 * width,
@ -856,6 +857,8 @@ static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
dp8393x_put(s, width, 0, 0);
address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
s->data, size);
/* 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);