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| author | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-23 03:29:33 +0200 |
|---|---|---|
| committer | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-23 03:29:33 +0200 |
| commit | 15dfd0df63ce6847081d09b2bbd567cc0cc4eae1 (patch) | |
| tree | 3b73f24fcef970bfcace3cbb297cfa57f3994682 /Documentation/DMA-API-HOWTO.txt | |
| parent | 328aa7a45af61bc0060c80847daa67fef7b9c0d0 (diff) | |
| parent | 0149138c4142da287d23f9d5c6038f7fb5e30ac2 (diff) | |
| download | kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.zip kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.tar.gz kernel_samsung_smdk4412-15dfd0df63ce6847081d09b2bbd567cc0cc4eae1.tar.bz2 | |
initial merge with 3.2.72
Diffstat (limited to 'Documentation/DMA-API-HOWTO.txt')
| -rw-r--r-- | Documentation/DMA-API-HOWTO.txt | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt index d568bc2..a0b6250 100644 --- a/Documentation/DMA-API-HOWTO.txt +++ b/Documentation/DMA-API-HOWTO.txt @@ -613,13 +613,13 @@ to use the dma_sync_*() interfaces. pass_to_upper_layers(cp->rx_buf); make_and_setup_new_rx_buf(cp); } else { - /* Just sync the buffer and give it back - * to the card. + /* CPU should not write to + * DMA_FROM_DEVICE-mapped area, + * so dma_sync_single_for_device() is + * not needed here. It would be required + * for DMA_BIDIRECTIONAL mapping if + * the memory was modified. */ - dma_sync_single_for_device(&cp->dev, - cp->rx_dma, - cp->rx_len, - DMA_FROM_DEVICE); give_rx_buf_to_card(cp); } } |