From: Fenghua Yu <fenghua.yu@xxxxxxxxx> When iwlwifi runs on IOMMU, IOMMU generates a lot of PTE write faults because PTE write bit is not set on some of PTE's. This is because iwlwifi driver calls DMA mapping with PCI_DMA_TODEVICE which is read only in mapping PTE. But iwlwifi device actually writes to the mapped page to update its contents. This issue is not exposed in swiotlb. But VT-d hardware can capture this fault and stop the fault transaction. The iwl TX command contains a scratch field that is updated by uCode to indicate retry counts. For 5000 series the patch is required also for regular frames, but this patch does not differenciate. Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx> Acked-by: Tomas Winkler <tomas.winkler@xxxxxxxxx> Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> --- This patch was posted on lkml: http://lkml.org/lkml/2009/2/11/306 drivers/net/wireless/iwlwifi/iwl-agn.c | 2 +- drivers/net/wireless/iwlwifi/iwl-tx.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c index 3c053ea..7046ea7 100644 --- a/drivers/net/wireless/iwlwifi/iwl-agn.c +++ b/drivers/net/wireless/iwlwifi/iwl-agn.c @@ -444,7 +444,7 @@ void iwl_hw_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq) pci_unmap_single(dev, pci_unmap_addr(&txq->cmd[index]->meta, mapping), pci_unmap_len(&txq->cmd[index]->meta, len), - PCI_DMA_TODEVICE); + PCI_DMA_BIDIRECTIONAL); /* Unmap chunks, if any. */ for (i = 1; i < num_tbs; i++) { diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c index ae04c20..dff60fb 100644 --- a/drivers/net/wireless/iwlwifi/iwl-tx.c +++ b/drivers/net/wireless/iwlwifi/iwl-tx.c @@ -819,7 +819,7 @@ int iwl_tx_skb(struct iwl_priv *priv, struct sk_buff *skb) * within command buffer array. */ txcmd_phys = pci_map_single(priv->pci_dev, out_cmd, sizeof(struct iwl_cmd), - PCI_DMA_TODEVICE); + PCI_DMA_BIDIRECTIONAL); pci_unmap_addr_set(&out_cmd->meta, mapping, txcmd_phys); pci_unmap_len_set(&out_cmd->meta, len, sizeof(struct iwl_cmd)); /* Add buffer containing Tx command and MAC(!) header to TFD's @@ -968,7 +968,7 @@ int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd) IWL_MAX_SCAN_SIZE : sizeof(struct iwl_cmd); phys_addr = pci_map_single(priv->pci_dev, out_cmd, - len, PCI_DMA_TODEVICE); + len, PCI_DMA_BIDIRECTIONAL); pci_unmap_addr_set(&out_cmd->meta, mapping, phys_addr); pci_unmap_len_set(&out_cmd->meta, len, len); phys_addr += offsetof(struct iwl_cmd, hdr); @@ -1068,7 +1068,7 @@ static void iwl_hcmd_queue_reclaim(struct iwl_priv *priv, int txq_id, pci_unmap_single(priv->pci_dev, pci_unmap_addr(&txq->cmd[cmd_idx]->meta, mapping), pci_unmap_len(&txq->cmd[cmd_idx]->meta, len), - PCI_DMA_TODEVICE); + PCI_DMA_BIDIRECTIONAL); for (idx = iwl_queue_inc_wrap(idx, q->n_bd); q->read_ptr != idx; q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) { -- 1.5.4.3 -- 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
