ath6kl: Fix the byte alignment rule to avoid loss of bytes in a TCP segment

Either first 3 bytes of the first received tcp segment or last one
over MTU size file can be loss due to the byte alignment problem.
Although ATH6KL_HTC_ALIGN_BYTES was defined for 'extra bytes for htc header
alignment' in the patch "Fix buffer alignment for scatter-gather
I/O"(1df94a857), there exists the bytes loss issue which means that it will be
truncated 3 bytes in the transmitted file contents if a file which has over MTU
size is transferred through TCP/IP stack.  It doesn't look like TCP/IP stack
bug of 3.5 or the latest version of kernel but the byte alignment issue.  This
patch is to use the roundup() function for the byte alignment rather than the
predefined ATH6KL_HTC_ALIGN_BYTES.

kvalo: fixed indentation

Signed-off-by: Myoungje Kim <mjei78@gmail.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath6kl/init.c b/drivers/net/wireless/ath/ath6kl/init.c
index 4ad45bb3cf55f217fa19b6ea150227aa536cca47..40ffee6184fd3b680037da63e0d35abcf44b4b6e 100644 (file)
--- a/drivers/net/wireless/ath/ath6kl/init.c
+++ b/drivers/net/wireless/ath/ath6kl/init.c
@@ -201,8 +201,8 @@ struct sk_buff *ath6kl_buf_alloc(int size)
        u16 reserved;
 
        /* Add chacheline space at front and back of buffer */
-       reserved = (2 * L1_CACHE_BYTES) + ATH6KL_DATA_OFFSET +
-                  sizeof(struct htc_packet) + ATH6KL_HTC_ALIGN_BYTES;
+       reserved = roundup((2 * L1_CACHE_BYTES) + ATH6KL_DATA_OFFSET +
+                  sizeof(struct htc_packet) + ATH6KL_HTC_ALIGN_BYTES, 4);
        skb = dev_alloc_skb(size + reserved);
 
        if (skb)

diff --git a/drivers/net/wireless/ath/ath6kl/main.c b/drivers/net/wireless/ath/ath6kl/main.c
index bad62b3357b91b0488548f48bb84e7ae5a7e128f..d4fcfcad57d03df4d612708978286997c4c42a9e 100644 (file)
--- a/drivers/net/wireless/ath/ath6kl/main.c
+++ b/drivers/net/wireless/ath/ath6kl/main.c
@@ -1294,9 +1294,11 @@ void init_netdev(struct net_device *dev)
        dev->watchdog_timeo = ATH6KL_TX_TIMEOUT;
 
        dev->needed_headroom = ETH_HLEN;
-       dev->needed_headroom += sizeof(struct ath6kl_llc_snap_hdr) +
-                               sizeof(struct wmi_data_hdr) + HTC_HDR_LENGTH
-                               + WMI_MAX_TX_META_SZ + ATH6KL_HTC_ALIGN_BYTES;
+       dev->needed_headroom += roundup(sizeof(struct ath6kl_llc_snap_hdr) +
+                                       sizeof(struct wmi_data_hdr) +
+                                       HTC_HDR_LENGTH +
+                                       WMI_MAX_TX_META_SZ +
+                                       ATH6KL_HTC_ALIGN_BYTES, 4);
 
        dev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_RXCSUM;