diff options
| author | Michael Brown <mcb30@ipxe.org> | 2024-03-16 23:25:07 +0000 |
|---|---|---|
| committer | Michael Brown <mcb30@ipxe.org> | 2024-03-16 23:28:34 +0000 |
| commit | bac967d51a8851ef274da6aa7a3a9711de0bb056 (patch) | |
| tree | a245646f5ced5b1f1ca00efdc186c257ad17059a | |
| parent | 17882e76afc0e69a0d4ed142aa33b94017ae4e58 (diff) | |
| download | ipxe-bac967d51a8851ef274da6aa7a3a9711de0bb056.tar.gz | |
[snp] Allocate additional padding for receive buffers
Some SNP implementations (observed with a wifi adapter in a Dell
Latitude 3440 laptop) seem to require additional space in the
allocated receive buffers, otherwise full-length packets will be
silently dropped.
The EDK2 MnpDxe driver happens to allocate an additional 8 bytes of
padding (4 for a VLAN tag, 4 for the Ethernet frame checksum). Match
this behaviour since drivers are very likely to have been tested
against MnpDxe.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
| -rw-r--r-- | src/drivers/net/efi/snpnet.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/src/drivers/net/efi/snpnet.c b/src/drivers/net/efi/snpnet.c index 3b09d4918..c66aa7d28 100644 --- a/src/drivers/net/efi/snpnet.c +++ b/src/drivers/net/efi/snpnet.c @@ -71,6 +71,19 @@ struct snp_nic { /** Delay between each initialisation retry */ #define SNP_INITIALIZE_RETRY_DELAY_MS 10 +/** Additional padding for receive buffers + * + * Some SNP implementations seem to require additional space in the + * allocated receive buffers, otherwise full-length packets will be + * silently dropped. + * + * The EDK2 MnpDxe driver happens to allocate an additional 8 bytes of + * padding (4 for a VLAN tag, 4 for the Ethernet frame checksum). + * Match this behaviour since drivers are very likely to have been + * tested against MnpDxe. + */ +#define SNP_RX_PAD 8 + /** * Format SNP MAC address (for debugging) * @@ -246,7 +259,7 @@ static void snpnet_poll_rx ( struct net_device *netdev ) { /* Allocate buffer, if required */ if ( ! snp->rxbuf ) { - snp->rxbuf = alloc_iob ( snp->mtu ); + snp->rxbuf = alloc_iob ( snp->mtu + SNP_RX_PAD ); if ( ! snp->rxbuf ) { /* Leave for next poll */ break; |