From: Ben Dooks <ben.dooks@codethink.co.uk>
To: netdev@vger.kernel.org
Cc: David.Laight@ACULAB.COM, oneukum@suse.com, davem@davemloft.net,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-kernel@lists.codethink.co.uk,
Ben Dooks <ben.dooks@codethink.co.uk>
Subject: [PATCH] usbnet: smsc95xx: simplify tx_fixup code
Date: Tue, 2 Oct 2018 17:56:02 +0100 [thread overview]
Message-ID: <20181002165602.21033-1-ben.dooks@codethink.co.uk> (raw)
In-Reply-To: <59988ed22559410881addfecf58335eb@AcuMS.aculab.com>
The smsc95xx_tx_fixup is doing multiple calls to skb_push() to
put an 8-byte command header onto the packet. It would be easier
to do one skb_push() and then copy the data in once the push is
done.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
---
drivers/net/usb/smsc95xx.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index cb19aea139d3..813ab93ee2c3 100644
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -2006,6 +2006,7 @@ static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev,
bool csum = skb->ip_summed == CHECKSUM_PARTIAL;
int overhead = csum ? SMSC95XX_TX_OVERHEAD_CSUM : SMSC95XX_TX_OVERHEAD;
u32 tx_cmd_a, tx_cmd_b;
+ void *ptr;
/* We do not advertise SG, so skbs should be already linearized */
BUG_ON(skb_shinfo(skb)->nr_frags);
@@ -2019,6 +2020,9 @@ static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev,
return NULL;
}
+ tx_cmd_b = (u32)skb->len;
+ tx_cmd_a = tx_cmd_b | TX_CMD_A_FIRST_SEG_ | TX_CMD_A_LAST_SEG_;
+
if (csum) {
if (skb->len <= 45) {
/* workaround - hardware tx checksum does not work
@@ -2035,21 +2039,18 @@ static struct sk_buff *smsc95xx_tx_fixup(struct usbnet *dev,
skb_push(skb, 4);
cpu_to_le32s(&csum_preamble);
memcpy(skb->data, &csum_preamble, 4);
+
+ tx_cmd_a += 4;
+ tx_cmd_b += 4;
+ tx_cmd_b |= TX_CMD_B_CSUM_ENABLE;
}
}
- 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) | TX_CMD_A_FIRST_SEG_ |
- TX_CMD_A_LAST_SEG_;
- cpu_to_le32s(&tx_cmd_a);
- memcpy(skb->data, &tx_cmd_a, 4);
+ ptr = skb_push(skb, 8);
+ tx_cmd_a = cpu_to_le32(tx_cmd_a);
+ tx_cmd_b = cpu_to_le32(tx_cmd_b);
+ memcpy(ptr, &tx_cmd_a, 4);
+ memcpy(ptr+4, &tx_cmd_b, 4);
return skb;
}
--
2.19.0
next prev parent reply other threads:[~2018-10-02 16:56 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-02 9:26 SMSC95XX driver updates Ben Dooks
2018-10-02 9:26 ` [PATCH 1/4] usbnet: smsc95xx: add kconfig for turbo mode Ben Dooks
2018-10-02 12:46 ` Andrew Lunn
2018-10-02 9:26 ` [PATCH 2/4] usbnet: smsc95xx: align tx-buffer to word Ben Dooks
2018-10-02 13:19 ` David Laight
2018-10-02 13:35 ` Ben Dooks
2018-10-02 16:56 ` Ben Dooks [this message]
2018-10-03 13:36 ` [PATCH] usbnet: smsc95xx: simplify tx_fixup code David Laight
2018-10-03 16:25 ` Ben Dooks
2018-10-05 21:24 ` David Miller
2018-10-06 11:27 ` Ben Dooks
2018-10-06 17:28 ` David Miller
2018-10-08 8:41 ` David Laight
2018-10-04 16:53 ` [Linux-kernel] [PATCH 2/4] usbnet: smsc95xx: align tx-buffer to word Ben Hutchings
2018-10-02 9:26 ` [PATCH 3/4] usbnet: smsc95xx: check for csum being in last four bytes Ben Dooks
2018-10-02 9:45 ` Sergei Shtylyov
2018-10-04 16:55 ` [Linux-kernel] " Ben Hutchings
2018-10-02 9:26 ` [PATCH 4/4] usbnet: smsc95xx: fix rx packet alignment Ben Dooks
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