net: mvpp2: allocate zeroed tx descriptors

[ Upstream commit a154f8e399a063137fc42b961f437248d55ece29 ]

Reserved and unused fields in the Tx descriptors should be 0. The PPv2
driver doesn't clear them at run-time (for performance reasons) but
these descriptors aren't zeroed when allocated, which can lead to
unpredictable behaviors. This patch fixes this by using
dma_zalloc_coherent instead of dma_alloc_coherent.

Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
Signed-off-by: Yan Markman <ymarkman@marvell.com>
[Antoine: commit message]
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/marvell/mvpp2.c
index 06f3fe4..529be74 100644 (file)
--- a/drivers/net/ethernet/marvell/mvpp2.c
+++ b/drivers/net/ethernet/marvell/mvpp2.c
@@ -5399,7 +5399,7 @@ static int mvpp2_aggr_txq_init(struct platform_device *pdev,
        u32 txq_dma;
 
        /* Allocate memory for TX descriptors */
-       aggr_txq->descs = dma_alloc_coherent(&pdev->dev,
+       aggr_txq->descs = dma_zalloc_coherent(&pdev->dev,
                                MVPP2_AGGR_TXQ_SIZE * MVPP2_DESC_ALIGNED_SIZE,
                                &aggr_txq->descs_dma, GFP_KERNEL);
        if (!aggr_txq->descs)