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authorMike Marciniszyn <mike.marciniszyn@intel.com>2020-05-04 09:09:17 -0400
committerJason Gunthorpe <jgg@mellanox.com>2020-05-12 11:47:48 -0300
commitfa8dac3968635dec8518a13ac78d662f2aa88e4d (patch)
treecfeed50711b4c4dd5bc64dc755fa0ea73b308a94 /drivers/infiniband/hw/hfi1/user_sdma.c
parent856ec7f64688387b100b7083cdf480ce3ac41227 (diff)
downloadlinux-fa8dac3968635dec8518a13ac78d662f2aa88e4d.tar.bz2
IB/hfi1: Fix another case where pq is left on waitlist
The commit noted below fixed a case where a pq is left on the sdma wait list. It however missed another case. user_sdma_send_pkts() has two calls from hfi1_user_sdma_process_request(). If the first one fails as indicated by -EBUSY, the pq will be placed on the waitlist as by design. If the second call then succeeds, the pq is still on the waitlist setting up a race with the interrupt handler if a subsequent request uses a different SDMA engine Fix by deleting the first call. The use of pcount and the intent to send a short burst of packets followed by the larger balance of packets was never correctly implemented, because the two calls always send pcount packets no matter what. A subsequent patch will correct that issue. Fixes: 9a293d1e21a6 ("IB/hfi1: Ensure pq is not left on waitlist") Link: https://lore.kernel.org/r/20200504130917.175613.43231.stgit@awfm-01.aw.intel.com Cc: <stable@vger.kernel.org> Reviewed-by: Kaike Wan <kaike.wan@intel.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband/hw/hfi1/user_sdma.c')
-rw-r--r--drivers/infiniband/hw/hfi1/user_sdma.c4
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/infiniband/hw/hfi1/user_sdma.c b/drivers/infiniband/hw/hfi1/user_sdma.c
index 13e4203497b3..a92346e88628 100644
--- a/drivers/infiniband/hw/hfi1/user_sdma.c
+++ b/drivers/infiniband/hw/hfi1/user_sdma.c
@@ -589,10 +589,6 @@ int hfi1_user_sdma_process_request(struct hfi1_filedata *fd,
set_comp_state(pq, cq, info.comp_idx, QUEUED, 0);
pq->state = SDMA_PKT_Q_ACTIVE;
- /* Send the first N packets in the request to buy us some time */
- ret = user_sdma_send_pkts(req, pcount);
- if (unlikely(ret < 0 && ret != -EBUSY))
- goto free_req;
/*
* This is a somewhat blocking send implementation.