diff options
author | Arnd Bergmann <arnd@arndb.de> | 2011-07-28 15:25:46 +0000 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2011-07-28 15:25:46 +0000 |
commit | 6124a4e430b64d1577438c8648c59e996d02e73e (patch) | |
tree | 49cfafad785d1c9e403a5b0d755298b9af2c260f /Documentation/DMA-API-HOWTO.txt | |
parent | 8e267f3da5f117d2f1316cf6ddf740f93f1c73aa (diff) | |
parent | 580975d7f48d7d047e22bb0f42adf7557801d8d4 (diff) |
Merge branch 'imx/dt' into next/dt
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 d568bc235bc..a0b6250add7 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); } } |