Commit 5b39fe30 authored by Ben Hutchings's avatar Ben Hutchings Committed by Jeff Garzik
Browse files

sfc: Remove mistaken hardware workaround 



We believed that some valid SNAP frames were being marked as invalid.
In fact this is not the case and no workaround is needed.

Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent 11f34e69

drivers/net/sfc/falcon.c

+4 −61
Original line number Diff line number Diff line
@@ -848,31 +848,11 @@ static inline void falcon_handle_tx_event(struct efx_channel *channel, 
	}

}



/* Check received packet's destination MAC address. */

static int check_dest_mac(struct efx_rx_queue *rx_queue,

			  const efx_qword_t *event)

{

	struct efx_rx_buffer *rx_buf;

	struct efx_nic *efx = rx_queue->efx;

	int rx_ev_desc_ptr;

	struct ethhdr *eh;



	if (efx->promiscuous)

		return 1;



	rx_ev_desc_ptr = EFX_QWORD_FIELD(*event, RX_EV_DESC_PTR);

	rx_buf = efx_rx_buffer(rx_queue, rx_ev_desc_ptr);

	eh = (struct ethhdr *)rx_buf->data;

	if (memcmp(eh->h_dest, efx->net_dev->dev_addr, ETH_ALEN))

		return 0;

	return 1;

}



/* Detect errors included in the rx_evt_pkt_ok bit. */

static void falcon_handle_rx_not_ok(struct efx_rx_queue *rx_queue,

				    const efx_qword_t *event,

				    unsigned *rx_ev_pkt_ok,

				    int *discard, int byte_count)

				    int *discard)

{

	struct efx_nic *efx = rx_queue->efx;

	unsigned rx_ev_buf_owner_id_err, rx_ev_ip_hdr_chksum_err;
@@ -880,7 +860,6 @@ static void falcon_handle_rx_not_ok(struct efx_rx_queue *rx_queue, 
	unsigned rx_ev_frm_trunc, rx_ev_drib_nib, rx_ev_tobe_disc;

	unsigned rx_ev_pkt_type, rx_ev_other_err, rx_ev_pause_frm;

	unsigned rx_ev_ip_frag_err, rx_ev_hdr_type, rx_ev_mcast_pkt;

	int snap, non_ip;



	rx_ev_hdr_type = EFX_QWORD_FIELD(*event, RX_EV_HDR_TYPE);

	rx_ev_mcast_pkt = EFX_QWORD_FIELD(*event, RX_EV_MCAST_PKT);
@@ -904,41 +883,6 @@ static void falcon_handle_rx_not_ok(struct efx_rx_queue *rx_queue, 
			   rx_ev_buf_owner_id_err | rx_ev_eth_crc_err |

			   rx_ev_frm_trunc | rx_ev_ip_hdr_chksum_err);



	snap = (rx_ev_pkt_type == RX_EV_PKT_TYPE_LLC_DECODE) ||

		(rx_ev_pkt_type == RX_EV_PKT_TYPE_VLAN_LLC_DECODE);

	non_ip = (rx_ev_hdr_type == RX_EV_HDR_TYPE_NON_IP_DECODE);



	/* SFC bug 5475/8970: The Falcon XMAC incorrectly calculates the

	 * length field of an LLC frame, which sets TOBE_DISC. We could set

	 * PASS_LEN_ERR, but we want the MAC to filter out short frames (to

	 * protect the RX block).

	 *

	 * bug5475 - LLC/SNAP: Falcon identifies SNAP packets.

	 * bug8970 - LLC/noSNAP: Falcon does not provide an LLC flag.

	 *                       LLC can't encapsulate IP, so by definition

	 *                       these packets are NON_IP.

	 *

	 * Unicast mismatch will also cause TOBE_DISC, so the driver needs

	 * to check this.

	 */

	if (EFX_WORKAROUND_5475(efx) && rx_ev_tobe_disc && (snap || non_ip)) {

		/* If all the other flags are zero then we can state the

		 * entire packet is ok, which will flag to the kernel not

		 * to recalculate checksums.

		 */

		if (!(non_ip | rx_ev_other_err | rx_ev_pause_frm))

			*rx_ev_pkt_ok = 1;



		rx_ev_tobe_disc = 0;



		/* TOBE_DISC is set for unicast mismatch.  But given that

		 * we can't trust TOBE_DISC here, we must validate the dest

		 * MAC address ourselves.

		 */

		if (!rx_ev_mcast_pkt && !check_dest_mac(rx_queue, event))

			rx_ev_tobe_disc = 1;

	}



	/* Count errors that are not in MAC stats. */

	if (rx_ev_frm_trunc)

		++rx_queue->channel->n_rx_frm_trunc;
@@ -962,7 +906,7 @@ static void falcon_handle_rx_not_ok(struct efx_rx_queue *rx_queue, 
#ifdef EFX_ENABLE_DEBUG

	if (rx_ev_other_err) {

		EFX_INFO_RL(efx, " RX queue %d unexpected RX event "

			    EFX_QWORD_FMT "%s%s%s%s%s%s%s%s%s\n",

			    EFX_QWORD_FMT "%s%s%s%s%s%s%s%s\n",

			    rx_queue->queue, EFX_QWORD_VAL(*event),

			    rx_ev_buf_owner_id_err ? " [OWNER_ID_ERR]" : "",

			    rx_ev_ip_hdr_chksum_err ?
@@ -973,8 +917,7 @@ static void falcon_handle_rx_not_ok(struct efx_rx_queue *rx_queue, 
			    rx_ev_frm_trunc ? " [FRM_TRUNC]" : "",

			    rx_ev_drib_nib ? " [DRIB_NIB]" : "",

			    rx_ev_tobe_disc ? " [TOBE_DISC]" : "",

			    rx_ev_pause_frm ? " [PAUSE]" : "",

			    snap ? " [SNAP/LLC]" : "");

			    rx_ev_pause_frm ? " [PAUSE]" : "");

	}

#endif
@@ -1041,7 +984,7 @@ static inline int falcon_handle_rx_event(struct efx_channel *channel, 
		checksummed = RX_EV_HDR_TYPE_HAS_CHECKSUMS(rx_ev_hdr_type);

	} else {

		falcon_handle_rx_not_ok(rx_queue, event, &rx_ev_pkt_ok,

					&discard, rx_ev_byte_cnt);

					&discard);

		checksummed = 0;

	}

drivers/net/sfc/workarounds.h

+0 −2
Original line number Diff line number Diff line
@@ -20,8 +20,6 @@ 


/* XAUI resets if link not detected */

#define EFX_WORKAROUND_5147 EFX_WORKAROUND_ALWAYS

/* SNAP frames have TOBE_DISC set */

#define EFX_WORKAROUND_5475 EFX_WORKAROUND_ALWAYS

/* RX PCIe double split performance issue */

#define EFX_WORKAROUND_7575 EFX_WORKAROUND_ALWAYS

/* TX pkt parser problem with <= 16 byte TXes */