iwlwifi: pcie: detect the DMA bug and warn if it happens

Warn if the DMA bug is going to happen. We don't have a good
way of actually aborting in this case and we have workarounds
in place for the cases where it happens, but in order to not
be surprised add a safety-check and warn.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
This commit is contained in:
Johannes Berg
2019-11-14 09:26:20 +01:00
committed by Luca Coelho
parent c4a786b326
commit c5a4e8eb68

View File

@@ -231,6 +231,17 @@ static int iwl_pcie_gen2_set_tb(struct iwl_trans *trans,
int idx = iwl_pcie_gen2_get_num_tbs(trans, tfd);
struct iwl_tfh_tb *tb;
/*
* Only WARN here so we know about the issue, but we mess up our
* unmap path because not every place currently checks for errors
* returned from this function - it can only return an error if
* there's no more space, and so when we know there is enough we
* don't always check ...
*/
WARN(crosses_4g_boundary(addr, len),
"possible DMA problem with iova:0x%llx, len:%d\n",
(unsigned long long)addr, len);
if (WARN_ON(idx >= IWL_TFH_NUM_TBS))
return -EINVAL;
tb = &tfd->tbs[idx];