| Message ID | 20160921105806.23980-1-rmanohar@qti.qualcomm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Kalle Valo |
| Headers | show |
Rajkumar Manoharan <rmanohar@qti.qualcomm.com> wrote: > Firmware is running watchdog timer for tracking copy engine ring index > and write index. Whenever both indices are stuck at same location for > given duration, watchdog will be trigger to assert target. While > updating copy engine destination ring write index, driver ensures that > write index will not be same as read index by finding delta between these > two indices (CE_RING_DELTA). > > HTT target to host copy engine (CE5) is special case where ring buffers > will be reused and delta check is not applied while updating write index. > In rare scenario, whenever CE5 ring is full, both indices will be referring > same location and this is causing CE ring stuck issue as explained > above. This issue is originally reported on IPQ4019 during long hour stress > testing and during veriwave max clients testsuites. The same issue is > also observed in other chips as well. Fix this by ensuring that write > index is one less than read index which means that full ring is > available for receiving data. > > Cc: stable@vger.kernel.org > Tested-by: Tamizh chelvam <c_traja@qti.qualcomm.com> > Signed-off-by: Rajkumar Manoharan <rmanohar@qti.qualcomm.com> Patch applied to ath-next branch of ath.git, thanks. 0628467f97b5 ath10k: fix copy engine 5 destination ring stuck
diff --git a/drivers/net/wireless/ath/ath10k/ce.c b/drivers/net/wireless/ath/ath10k/ce.c index 65d8d714e917..00d3f93058db 100644 --- a/drivers/net/wireless/ath/ath10k/ce.c +++ b/drivers/net/wireless/ath/ath10k/ce.c @@ -433,6 +433,13 @@ void ath10k_ce_rx_update_write_idx(struct ath10k_ce_pipe *pipe, u32 nentries) unsigned int nentries_mask = dest_ring->nentries_mask; unsigned int write_index = dest_ring->write_index; u32 ctrl_addr = pipe->ctrl_addr; + u32 cur_write_idx = ath10k_ce_dest_ring_write_index_get(ar, ctrl_addr); + + /* Prevent CE ring stuck issue that will occur when ring is full. + * Make sure that write index is 1 less than read index. + */ + if ((cur_write_idx + nentries) == dest_ring->sw_index) + nentries -= 1; write_index = CE_RING_IDX_ADD(nentries_mask, write_index, nentries); ath10k_ce_dest_ring_write_index_set(ar, ctrl_addr, write_index);