6.12-stable review patch. If anyone has any objections, please let me know.
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From: Joshua Hay joshua.a.hay@intel.com
[ Upstream commit 4c69c77aafe74cf755af55070584b643e5c4e4d8 ]
Commit d9028db618a6 ("idpf: convert to libeth Tx buffer completion") inadvertently removed code that was necessary for the tx buffer cleaning routine to iterate over all buffers associated with a packet.
When a frag is too large for a single data descriptor, it will be split across multiple data descriptors. This means the frag will span multiple buffers in the buffer ring in order to keep the descriptor and buffer ring indexes aligned. The buffer entries in the ring are technically empty and no cleaning actions need to be performed. These empty buffers can precede other frags associated with the same packet. I.e. a single packet on the buffer ring can look like:
buf[0]=skb0.frag0 buf[1]=skb0.frag1 buf[2]=empty buf[3]=skb0.frag2
The cleaning routine iterates through these buffers based on a matching completion tag. If the completion tag is not set for buf2, the loop will end prematurely. Frag2 will be left uncleaned and next_to_clean will be left pointing to the end of packet, which will break the cleaning logic for subsequent cleans. This consequently leads to tx timeouts.
Assign the empty bufs the same completion tag for the packet to ensure the cleaning routine iterates over all of the buffers associated with the packet.
Fixes: d9028db618a6 ("idpf: convert to libeth Tx buffer completion") Signed-off-by: Joshua Hay joshua.a.hay@intel.com Acked-by: Alexander Lobakin aleksander.lobakin@intel.com Reviewed-by: Madhu chittim madhu.chittim@intel.com Reviewed-by: Simon Horman horms@kernel.org Tested-by: Krishneil Singh krishneil.k.singh@intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/idpf/idpf_txrx.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c index d4e6f0e104872..60d15b3e6e2fa 100644 --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c @@ -2448,6 +2448,7 @@ static void idpf_tx_splitq_map(struct idpf_tx_queue *tx_q, * rest of the packet. */ tx_buf->type = LIBETH_SQE_EMPTY; + idpf_tx_buf_compl_tag(tx_buf) = params->compl_tag;
/* Adjust the DMA offset and the remaining size of the * fragment. On the first iteration of this loop,