diff options
| author | Selvin Xavier <selvin.xavier@broadcom.com> | 2024-10-08 09:41:38 +0200 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2024-10-12 01:49:01 +0200 |
| commit | 8be3e5b0c96beeefe9d5486b96575d104d3e7d17 (patch) | |
| tree | 70e720afbe6d5b66a7d77dd8834793e53a8216da /drivers/infiniband | |
| parent | RDMA/bnxt_re: Fix a possible NULL pointer dereference (diff) | |
| download | linux-8be3e5b0c96beeefe9d5486b96575d104d3e7d17.tar.xz linux-8be3e5b0c96beeefe9d5486b96575d104d3e7d17.zip | |
RDMA/bnxt_re: Avoid CPU lockups due fifo occupancy check loop
Driver waits indefinitely for the fifo occupancy to go below a threshold
as soon as the pacing interrupt is received. This can cause soft lockup on
one of the processors, if the rate of DB is very high.
Add a loop count for FPGA and exit the __wait_for_fifo_occupancy_below_th
if the loop is taking more time. Pacing will be continuing until the
occupancy is below the threshold. This is ensured by the checks in
bnxt_re_pacing_timer_exp and further scheduling the work for pacing based
on the fifo occupancy.
Fixes: 2ad4e6303a6d ("RDMA/bnxt_re: Implement doorbell pacing algorithm")
Link: https://patch.msgid.link/r/1728373302-19530-7-git-send-email-selvin.xavier@broadcom.com
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Chandramohan Akula <chandramohan.akula@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/hw/bnxt_re/main.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/bnxt_re/main.c b/drivers/infiniband/hw/bnxt_re/main.c index 915b0d3a709a..b1dcb6bdac95 100644 --- a/drivers/infiniband/hw/bnxt_re/main.c +++ b/drivers/infiniband/hw/bnxt_re/main.c @@ -534,6 +534,7 @@ static bool is_dbr_fifo_full(struct bnxt_re_dev *rdev) static void __wait_for_fifo_occupancy_below_th(struct bnxt_re_dev *rdev) { struct bnxt_qplib_db_pacing_data *pacing_data = rdev->qplib_res.pacing_data; + u32 retry_fifo_check = 1000; u32 fifo_occup; /* loop shouldn't run infintely as the occupancy usually goes @@ -547,6 +548,14 @@ static void __wait_for_fifo_occupancy_below_th(struct bnxt_re_dev *rdev) if (fifo_occup < pacing_data->pacing_th) break; + if (!retry_fifo_check--) { + dev_info_once(rdev_to_dev(rdev), + "%s: fifo_occup = 0x%xfifo_max_depth = 0x%x pacing_th = 0x%x\n", + __func__, fifo_occup, pacing_data->fifo_max_depth, + pacing_data->pacing_th); + break; + } + } } |