From: Johannes Berg <johannes.berg@xxxxxxxxx> 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@xxxxxxxxx> Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx> --- drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c index b2a3a1c18bec..090c1156bc21 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c @@ -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]; -- 2.24.0
