[ 159/173] iwlwifi: handle DMA mapping failures
From: Ben Hutchings <hidden>
Date: 2012-12-28 19:56:20
Also in:
lkml
3.2-stable review patch. If anyone has any objections, please let me know.
------------------
From: Johannes Berg <redacted>
commit 7c34158231b2eda8dcbd297be2bb1559e69cb433 upstream.
The RX replenish code doesn't handle DMA mapping failures,
which will cause issues if there actually is a failure. This
was reported by Shuah Khan who found a DMA mapping framework
warning ("device driver failed to check map error").
Reported-by: Shuah Khan <redacted>
Reviewed-by: Emmanuel Grumbach <redacted>
Signed-off-by: Johannes Berg <redacted>
[bwh: Backported to 3.2:
- Adjust filename, context, indentation
- Use bus(trans) instead of trans where necessary
- Use hw_params(trans).rx_page_order instead of trans_pcie->rx_page_order]
Signed-off-by: Ben Hutchings <redacted>
---
drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
--- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c@@ -311,6 +311,14 @@ static void iwlagn_rx_allocate(struct iw rxb->page_dma = dma_map_page(bus(trans)->dev, page, 0, PAGE_SIZE << hw_params(trans).rx_page_order, DMA_FROM_DEVICE); + if (dma_mapping_error(bus(trans)->dev, rxb->page_dma)) { + rxb->page = NULL; + spin_lock_irqsave(&rxq->lock, flags); + list_add(&rxb->list, &rxq->rx_used); + spin_unlock_irqrestore(&rxq->lock, flags); + __free_pages(page, hw_params(trans).rx_page_order); + return; + } /* dma address must be no more than 36 bits */ BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36)); /* and also 256 byte aligned! */
@@ -489,8 +497,19 @@ static void iwl_rx_handle(struct iwl_tra 0, PAGE_SIZE << hw_params(trans).rx_page_order, DMA_FROM_DEVICE); - list_add_tail(&rxb->list, &rxq->rx_free); - rxq->free_count++; + if (dma_mapping_error(bus(trans)->dev, rxb->page_dma)) { + /* + * free the page(s) as well to not break + * the invariant that the items on the used + * list have no page(s) + */ + __free_pages(rxb->page, hw_params(trans).rx_page_order); + rxb->page = NULL; + list_add_tail(&rxb->list, &rxq->rx_used); + } else { + list_add_tail(&rxb->list, &rxq->rx_free); + rxq->free_count++; + } } else list_add_tail(&rxb->list, &rxq->rx_used);