[PATCH v3 1/7] net: moxa: clear TX descriptor length bits between sends

[Jonas Jensen <jonas.jensen@gmail.com>]

Add TX_DESC1_BUF_SIZE_MASK to bits that are cleared, before the TX buffer
length is set. Failing to do so can cause the controller to drop dead
i.e. all TX interrupts stop, resulting in complete communication failure.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=69031

Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com>
---

Notes:
    Applies to next-20140120

 drivers/net/ethernet/moxa/moxart_ether.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/moxa/moxart_ether.c b/drivers/net/ethernet/moxa/moxart_ether.c
index 5020fd4..aa45607 100644
--- a/drivers/net/ethernet/moxa/moxart_ether.c
+++ b/drivers/net/ethernet/moxa/moxart_ether.c
@@ -348,7 +348,8 @@ static int moxart_mac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 
 	txdes1 = readl(desc + TX_REG_OFFSET_DESC1);
 	txdes1 |= TX_DESC1_LTS | TX_DESC1_FTS;
-	txdes1 &= ~(TX_DESC1_FIFO_COMPLETE | TX_DESC1_INTR_COMPLETE);
+	txdes1 &= ~(TX_DESC1_FIFO_COMPLETE | TX_DESC1_INTR_COMPLETE |
+		    TX_DESC1_BUF_SIZE_MASK);
 	txdes1 |= (len & TX_DESC1_BUF_SIZE_MASK);
 	writel(txdes1, desc + TX_REG_OFFSET_DESC1);
 	writel(TX_DESC0_DMA_OWN, desc + TX_REG_OFFSET_DESC0);
-- 
1.8.2.1