[PATCH 04/11] iwlwifi: pcie: avoid dma unmap/remap in crash dump
From: Luca Coelho <hidden>
Date: 2021-08-19 15:40:45
Subsystem:
intel wireless wifi link (iwlwifi), the rest · Maintainers:
Miri Korenblit, Linus Torvalds
From: Johannes Berg <redacted> DMA-API debug code pointed out that in this code path we never check the return value of dma_map_page(), which could fail. However, we don't really even want to unmap/remap, we just want to ensure that we can actually access the last version of the data that the (now-dead) device may have written, so only need to dma_sync_single_for_cpu() instead. Signed-off-by: Johannes Berg <redacted> Signed-off-by: Luca Coelho <redacted> --- drivers/net/wireless/intel/iwlwifi/pcie/trans.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index 86a949440486..1e6af3cbe026 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c@@ -2968,8 +2968,8 @@ static u32 iwl_trans_pcie_dump_rbs(struct iwl_trans *trans, struct iwl_rx_mem_buffer *rxb = rxq->queue[i]; struct iwl_fw_error_dump_rb *rb; - dma_unmap_page(trans->dev, rxb->page_dma, max_len, - DMA_FROM_DEVICE); + dma_sync_single_for_cpu(trans->dev, rxb->page_dma, + max_len, DMA_FROM_DEVICE); rb_len += sizeof(**data) + sizeof(*rb) + max_len;
@@ -2978,10 +2978,6 @@ static u32 iwl_trans_pcie_dump_rbs(struct iwl_trans *trans, rb = (void *)(*data)->data; rb->index = cpu_to_le32(i); memcpy(rb->data, page_address(rxb->page), max_len); - /* remap the page for the free benefit */ - rxb->page_dma = dma_map_page(trans->dev, rxb->page, - rxb->offset, max_len, - DMA_FROM_DEVICE); *data = iwl_fw_error_next_data(*data); }
--
2.33.0