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From fb13c1342c81bb0c06afdcfe1e8561e8a6e149d7 Mon Sep 17 00:00:00 2001
From: P33M <p33m@github.com>
Date: Tue, 14 May 2019 14:55:19 +0100
Subject: [PATCH 497/703] Revert "smsc95xx: dynamically fix up TX buffer
alignment with padding bytes"
As reported in https://github.com/raspberrypi/linux/issues/2964 this
commit causes a regression corrupting non-option TCP ack packets.
This reverts commit 96b972dc736d943f371a16ccca452a053d83c65b.
---
drivers/net/usb/smsc95xx.c | 12 +++++-------
drivers/net/usb/smsc95xx.h | 2 +-
2 files changed, 6 insertions(+), 8 deletions(-)
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -2082,9 +2082,7 @@ static struct sk_buff *smsc95xx_tx_fixup
struct sk_buff *skb, gfp_t flags)
{
bool csum = skb->ip_summed == CHECKSUM_PARTIAL;
- unsigned int align_bytes = -((uintptr_t)skb->data) & 0x3;
- int overhead = csum ? SMSC95XX_TX_OVERHEAD_CSUM + align_bytes
- : SMSC95XX_TX_OVERHEAD + align_bytes;
+ int overhead = csum ? SMSC95XX_TX_OVERHEAD_CSUM : SMSC95XX_TX_OVERHEAD;
u32 tx_cmd_a, tx_cmd_b;
/* We do not advertise SG, so skbs should be already linearized */
@@ -2118,16 +2116,16 @@ static struct sk_buff *smsc95xx_tx_fixup
}
}
- skb_push(skb, 4 + align_bytes);
- tx_cmd_b = (u32)(skb->len - 4 - align_bytes);
+ skb_push(skb, 4);
+ tx_cmd_b = (u32)(skb->len - 4);
if (csum)
tx_cmd_b |= TX_CMD_B_CSUM_ENABLE;
cpu_to_le32s(&tx_cmd_b);
memcpy(skb->data, &tx_cmd_b, 4);
skb_push(skb, 4);
- tx_cmd_a = (u32)(skb->len - 8 - align_bytes) | TX_CMD_A_FIRST_SEG_ |
- (align_bytes << 16) | TX_CMD_A_LAST_SEG_;
+ tx_cmd_a = (u32)(skb->len - 8) | TX_CMD_A_FIRST_SEG_ |
+ TX_CMD_A_LAST_SEG_;
cpu_to_le32s(&tx_cmd_a);
memcpy(skb->data, &tx_cmd_a, 4);
--- a/drivers/net/usb/smsc95xx.h
+++ b/drivers/net/usb/smsc95xx.h
@@ -21,7 +21,7 @@
#define _SMSC95XX_H
/* Tx command words */
-#define TX_CMD_A_DATA_OFFSET_ (0x00030000) /* Data Start Offset */
+#define TX_CMD_A_DATA_OFFSET_ (0x001F0000) /* Data Start Offset */
#define TX_CMD_A_FIRST_SEG_ (0x00002000) /* First Segment */
#define TX_CMD_A_LAST_SEG_ (0x00001000) /* Last Segment */
#define TX_CMD_A_BUF_SIZE_ (0x000007FF) /* Buffer Size */
|