Re: [PATCH] sky2: Account for VLAN tag in tx_le_req
From: Stephen Hemminger <hidden>
Date: 2009-09-12 04:42:36
On Sat, 12 Sep 2009 12:17:29 +0900 Mike McCormack [off-list ref] wrote:
quoted hunk ↗ jump to hunk
With VLAN enabled, tx_le_req would return on less list elements than required, leading to a potential wrap around of the transmit ring buffer. Signed-off-by: Mike McCormack <redacted> --- drivers/net/sky2.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-)diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c index 00bc65a..018aa58 100644 --- a/drivers/net/sky2.c +++ b/drivers/net/sky2.c@@ -66,7 +66,7 @@ /* This is the worst case number of transmit list elements for a single skb: VLAN + TSO + CKSUM + Data + skb_frags * DMA */ -#define MAX_SKB_TX_LE (4 + (sizeof(dma_addr_t)/sizeof(u32))*MAX_SKB_FRAGS) +#define MAX_SKB_TX_LE (5 + (sizeof(dma_addr_t)/sizeof(u32))*MAX_SKB_FRAGS) #define TX_MIN_PENDING (MAX_SKB_TX_LE+1) #define TX_MAX_PENDING 4096 #define TX_DEF_PENDING 127@@ -1576,6 +1576,11 @@ static unsigned tx_le_req(const struct sk_buff *skb) if (skb->ip_summed == CHECKSUM_PARTIAL) ++count; +#ifdef SKY2_VLAN_TAG_USED + if (vlan_tx_tag_present(skb)) + ++count; +#endif + return count; }
The vlan tag can be nested with either ADDR64 or GSO element.
The correct test would be to do something like:
if (skb_is_gso(skb))
++count;
else if (sizeof(dma_addr_t) == sizeof(u32) &&
vlan_tx_tag_present(skb))
++count;
And the MAX_SKB_TX_LE value is fine.
--