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Commit 69077577 authored by Jacob Keller's avatar Jacob Keller Committed by Jeff Kirsher
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i40e: avoid permanent lock of *_PTP_TX_IN_PROGRESS 



The i40e driver uses a bit lock to indicate when a Tx timestamp is in
progress to avoid attempting to timestamp multiple packets at once. This
is required because hardware only has registers to handle one request at
a time.

There is a corner case where we failed to cleanup the bit lock after
a failed transmit. This can potentially result in a state bit being
locked forever.

Add some cleanup code to i40e_xmit_frame_ring to check and make sure we
cleanup incase of these failures. We also modify i40e_tx_map to return
an error code indication DMA failure.

Reported-by: default avatarReported-by: David Mirabito <davidm@metamako.com>
Signed-off-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent bbc4e7d2

drivers/net/ethernet/intel/i40e/i40e_txrx.c

+20 −6
Original line number Diff line number Diff line
@@ -2932,8 +2932,10 @@ bool __i40e_chk_linearize(struct sk_buff *skb) 
 * @hdr_len:  size of the packet header

 * @td_cmd:   the command field in the descriptor

 * @td_offset: offset for checksum or crc

 *

 * Returns 0 on success, -1 on failure to DMA

 **/

static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,

static inline int i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,

			      struct i40e_tx_buffer *first, u32 tx_flags,

			      const u8 hdr_len, u32 td_cmd, u32 td_offset)

{
@@ -3093,7 +3095,7 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb, 
		mmiowb();

	}



	return;

	return 0;



dma_error:

	dev_info(tx_ring->dev, "TX DMA map failed\n");
@@ -3110,6 +3112,8 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb, 
	}



	tx_ring->next_to_use = i;



	return -1;

}



/**
@@ -3210,8 +3214,9 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb, 
	 */

	i40e_atr(tx_ring, skb, tx_flags);



	i40e_tx_map(tx_ring, skb, first, tx_flags, hdr_len,

		    td_cmd, td_offset);

	if (i40e_tx_map(tx_ring, skb, first, tx_flags, hdr_len,

			td_cmd, td_offset))

		goto cleanup_tx_tstamp;



	return NETDEV_TX_OK;
@@ -3219,6 +3224,15 @@ static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb, 
	i40e_trace(xmit_frame_ring_drop, first->skb, tx_ring);

	dev_kfree_skb_any(first->skb);

	first->skb = NULL;

cleanup_tx_tstamp:

	if (unlikely(tx_flags & I40E_TX_FLAGS_TSYN)) {

		struct i40e_pf *pf = i40e_netdev_to_pf(tx_ring->netdev);



		dev_kfree_skb_any(pf->ptp_tx_skb);

		pf->ptp_tx_skb = NULL;

		clear_bit_unlock(__I40E_PTP_TX_IN_PROGRESS, pf->state);

	}



	return NETDEV_TX_OK;

}