From: Finn Thain Date: Wed, 22 Jan 2020 22:07:26 +0000 (+1100) Subject: net/sonic: Improve receive descriptor status flag check X-Git-Tag: v4.19.100~43 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1de65d2cadb9bf6c126a69bce017b3c1162c1689;p=platform%2Fkernel%2Flinux-rpi.git net/sonic: Improve receive descriptor status flag check commit 94b166349503957079ef5e7d6f667f157aea014a upstream. After sonic_tx_timeout() calls sonic_init(), it can happen that sonic_rx() will subsequently encounter a receive descriptor with no flags set. Remove the comment that says that this can't happen. When giving a receive descriptor to the SONIC, clear the descriptor status field. That way, any rx descriptor with flags set can only be a newly received packet. Don't process a descriptor without the LPKT bit set. The buffer is still in use by the SONIC. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Tested-by: Stan Johnson Signed-off-by: Finn Thain Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/ethernet/natsemi/sonic.c b/drivers/net/ethernet/natsemi/sonic.c index 0c62ef5..bc15f97 100644 --- a/drivers/net/ethernet/natsemi/sonic.c +++ b/drivers/net/ethernet/natsemi/sonic.c @@ -433,7 +433,6 @@ static int index_from_addr(struct sonic_local *lp, dma_addr_t addr, static void sonic_rx(struct net_device *dev) { struct sonic_local *lp = netdev_priv(dev); - int status; int entry = lp->cur_rx; int prev_entry = lp->eol_rx; @@ -444,9 +443,10 @@ static void sonic_rx(struct net_device *dev) u16 bufadr_l; u16 bufadr_h; int pkt_len; + u16 status = sonic_rda_get(dev, entry, SONIC_RD_STATUS); - status = sonic_rda_get(dev, entry, SONIC_RD_STATUS); - if (status & SONIC_RCR_PRX) { + /* If the RD has LPKT set, the chip has finished with the RB */ + if ((status & SONIC_RCR_PRX) && (status & SONIC_RCR_LPKT)) { u32 addr = (sonic_rda_get(dev, entry, SONIC_RD_PKTPTR_H) << 16) | sonic_rda_get(dev, entry, SONIC_RD_PKTPTR_L); @@ -494,10 +494,6 @@ static void sonic_rx(struct net_device *dev) bufadr_h = (unsigned long)new_laddr >> 16; sonic_rra_put(dev, i, SONIC_RR_BUFADR_L, bufadr_l); sonic_rra_put(dev, i, SONIC_RR_BUFADR_H, bufadr_h); - } else { - /* This should only happen, if we enable accepting broken packets. */ - } - if (status & SONIC_RCR_LPKT) { /* * this was the last packet out of the current receive buffer * give the buffer back to the SONIC @@ -510,12 +506,11 @@ static void sonic_rx(struct net_device *dev) __func__); SONIC_WRITE(SONIC_ISR, SONIC_INT_RBE); /* clear the flag */ } - } else - printk(KERN_ERR "%s: rx desc without RCR_LPKT. Shouldn't happen !?\n", - dev->name); + } /* * give back the descriptor */ + sonic_rda_put(dev, entry, SONIC_RD_STATUS, 0); sonic_rda_put(dev, entry, SONIC_RD_IN_USE, 1); prev_entry = entry;