diff options
Diffstat (limited to 'Documentation/driver-api/dmaengine/provider.rst')
| -rw-r--r-- | Documentation/driver-api/dmaengine/provider.rst | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/Documentation/driver-api/dmaengine/provider.rst b/Documentation/driver-api/dmaengine/provider.rst index 3085f8b460fa..f4ed98f701c9 100644 --- a/Documentation/driver-api/dmaengine/provider.rst +++ b/Documentation/driver-api/dmaengine/provider.rst @@ -172,8 +172,8 @@ Currently, the types available are: - It's usually used for copying pixel data between host memory and memory-mapped GPU device memory, such as found on modern PCI video graphics cards. The most immediate example is the OpenGL API function - ``glReadPielx()``, which might require a verbatim copy of a huge framebuffer - from local device memory onto host memory. + ``glReadPixels()``, which might require a verbatim copy of a huge + framebuffer from local device memory onto host memory. - DMA_XOR @@ -217,10 +217,12 @@ Currently, the types available are: - DMA_ASYNC_TX - - Must not be set by the device, and will be set by the framework - if needed + - The device supports asynchronous memory-to-memory operations, + including memcpy, memset, xor, pq, xor_val, and pq_val. - - TODO: What is it about? + - This capability is automatically set by the DMA engine + framework and must not be configured manually by device + drivers. - DMA_SLAVE @@ -409,7 +411,7 @@ supported. - This structure can be initialized using the function ``dma_async_tx_descriptor_init``. - - You'll also need to set two fields in this structure: + - You'll also need to set following fields in this structure: - flags: TODO: Can it be modified by the driver itself, or @@ -419,6 +421,9 @@ supported. that is supposed to push the current transaction descriptor to a pending queue, waiting for issue_pending to be called. + - phys: Physical address of the descriptor which is used later by + the dma engine to read the descriptor and initiate transfer. + - In this structure the function pointer callback_result can be initialized in order for the submitter to be notified that a transaction has completed. In the earlier code the function pointer |