From: Johannes Berg Date: Thu, 19 Aug 2021 15:40:28 +0000 (+0300) Subject: iwlwifi: pcie: avoid dma unmap/remap in crash dump X-Git-Tag: v5.15~428^2~33^2~7^2~14 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=59a6ee97e0d4d8f9f3f47df1b82d850ce8e0f0b1;p=platform%2Fkernel%2Flinux-starfive.git iwlwifi: pcie: avoid dma unmap/remap in crash dump 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 Signed-off-by: Luca Coelho Link: https://lore.kernel.org/r/iwlwifi.20210819183728.5987f35883a2.I2d9ea5ecc69a5e5947b546fb15f33363a0595651@changeid Signed-off-by: Luca Coelho --- diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c index 86a9494..1e6af3c 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); }