On Mon, Oct 10, 2011 at 07:27:02AM -0700, Wey-Yi Guy wrote: > While inspecting the code, I saw that iwl_tx_queue_unmap modifies > the read pointer of the Tx queue without taking any locks. This means > that it can race with the reclaim flow. This can possibly lead to > a DMA warning complaining that we unmap the same buffer twice. > > This is more a W/A than a fix since it is really weird to take > sta_lock inside iwl_tx_queue_unmap, but it can help until we revamp > the locking model in the transport layer. > > Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx> > Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@xxxxxxxxx> > --- > drivers/net/wireless/iwlwifi/iwl-trans-pcie.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c > index 60067c7..f69aecb 100644 > --- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c > +++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie.c > @@ -406,6 +406,7 @@ static void iwl_tx_queue_unmap(struct iwl_trans *trans, int txq_id) > struct iwl_tx_queue *txq = &trans_pcie->txq[txq_id]; > struct iwl_queue *q = &txq->q; > enum dma_data_direction dma_dir; > + unsigned long flags; > > if (!q->n_bd) > return; > @@ -418,12 +419,14 @@ static void iwl_tx_queue_unmap(struct iwl_trans *trans, int txq_id) > else > dma_dir = DMA_TO_DEVICE; > > + spin_lock_irqsave(&trans->shrd->sta_lock, flags); sta_lock does not look like right lock to use. Stanislaw -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
