From: Mike Marciniszyn mike.marciniszyn@intel.com
[ Upstream commit 18912c4524385dd6532c682cb9d4f6aa39ba8d47 ]
The call to sdma_progress() is called outside the wait lock.
In this case, there is a race condition where sdma_progress() can return false and the sdma_engine can idle. If that happens, there will be no more sdma interrupts to cause the wakeup and the vnic_sdma xmit will hang.
Fix by moving the lock to enclose the sdma_progress() call.
Also, delete the tx_retry. The need for this was removed by: commit bcad29137a97 ("IB/hfi1: Serve the most starved iowait entry first")
Fixes: 64551ede6cd1 ("IB/hfi1: VNIC SDMA support") Reviewed-by: Gary Leshner Gary.S.Leshner@intel.com Signed-off-by: Mike Marciniszyn mike.marciniszyn@intel.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@intel.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/hw/hfi1/vnic_sdma.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/vnic_sdma.c b/drivers/infiniband/hw/hfi1/vnic_sdma.c index c3c96c5869ed4..718dcdef946ee 100644 --- a/drivers/infiniband/hw/hfi1/vnic_sdma.c +++ b/drivers/infiniband/hw/hfi1/vnic_sdma.c @@ -57,7 +57,6 @@
#define HFI1_VNIC_TXREQ_NAME_LEN 32 #define HFI1_VNIC_SDMA_DESC_WTRMRK 64 -#define HFI1_VNIC_SDMA_RETRY_COUNT 1
/* * struct vnic_txreq - VNIC transmit descriptor @@ -67,7 +66,6 @@ * @pad: pad buffer * @plen: pad length * @pbc_val: pbc value - * @retry_count: tx retry count */ struct vnic_txreq { struct sdma_txreq txreq; @@ -77,8 +75,6 @@ struct vnic_txreq { unsigned char pad[HFI1_VNIC_MAX_PAD]; u16 plen; __le64 pbc_val; - - u32 retry_count; };
static void vnic_sdma_complete(struct sdma_txreq *txreq, @@ -196,7 +192,6 @@ int hfi1_vnic_send_dma(struct hfi1_devdata *dd, u8 q_idx, ret = build_vnic_tx_desc(sde, tx, pbc); if (unlikely(ret)) goto free_desc; - tx->retry_count = 0;
ret = sdma_send_txreq(sde, &vnic_sdma->wait, &tx->txreq, vnic_sdma->pkts_sent); @@ -238,14 +233,14 @@ static int hfi1_vnic_sdma_sleep(struct sdma_engine *sde, struct hfi1_vnic_sdma *vnic_sdma = container_of(wait, struct hfi1_vnic_sdma, wait); struct hfi1_ibdev *dev = &vnic_sdma->dd->verbs_dev; - struct vnic_txreq *tx = container_of(txreq, struct vnic_txreq, txreq);
- if (sdma_progress(sde, seq, txreq)) - if (tx->retry_count++ < HFI1_VNIC_SDMA_RETRY_COUNT) - return -EAGAIN; + write_seqlock(&dev->iowait_lock); + if (sdma_progress(sde, seq, txreq)) { + write_sequnlock(&dev->iowait_lock); + return -EAGAIN; + }
vnic_sdma->state = HFI1_VNIC_SDMA_Q_DEFERRED; - write_seqlock(&dev->iowait_lock); if (list_empty(&vnic_sdma->wait.list)) iowait_queue(pkts_sent, wait, &sde->dmawait); write_sequnlock(&dev->iowait_lock);