linux-dev/Documentation/dmaengine/provider.txt, branch linus/master

dmaengine: doc: ReSTize provider doc

2017-11-05T17:03:23Z

This moves and converts provider file with some format changes for RST style Signed-off-by: Vinod Koul Signed-off-by: Jonathan Corbet

Merge branch 'topic/dmatest' into for-linus

2017-09-06T16:25:10Z

dmaengine: add DMA_PREP_CMD for non-Data descriptors.

2017-08-28T11:10:18Z

Some of the DMA controllers are capable of issuing the commands to peripheral by the DMA. These commands can be list of register reads/writes and its different from normal data reads/writes. This patch adds new flag DMA_PREP_CMD in DMA API which tells the driver that the data passed to DMA API is command data and DMA controller driver will form descriptor in the required format. This flag can be used by any DMA controller driver which requires the descriptor in different format for non-Data descriptors. Signed-off-by: Abhishek Sahu Signed-off-by: Vinod Koul

dmaengine: remove DMA_SG as it is dead code in kernel

2017-08-22T03:52:11Z

There are no in kernel consumers for DMA_SG op. Removing operation, dead code, and test code in dmatest. Signed-off-by: Dave Jiang Reviewed-by: Linus Walleij Cc: Gary Hook Cc: Ludovic Desroches Cc: Kedareswara rao Appana Cc: Li Yang Cc: Michal Simek Signed-off-by: Vinod Koul

dmaengine: Documentation: Fix typo in provider.txt

2016-11-14T02:44:19Z

Signed-off-by: Vinod Koul

dmaengine: documentation to the new callback mechanism

2016-08-08T02:41:42Z

Adding documentation in dmaengine/provider.txt on the usage of callback with result, callback_result, function pointer to retrieve transanction result from a DMA submission. Signed-off-by: Dave Jiang Reviewed-by: Lars-Peter Clausen Signed-off-by: Vinod Koul

Documentation: dmaengine: fix typo for device_resume

2016-06-03T20:00:21Z

Signed-off-by: Niklas Söderlund Signed-off-by: Jonathan Corbet

dmaengine: Add transfer termination synchronization support

2015-11-16T02:58:52Z

The DMAengine API has a long standing race condition that is inherent to the API itself. Calling dmaengine_terminate_all() is supposed to stop and abort any pending or active transfers that have previously been submitted. Unfortunately it is possible that this operation races against a currently running (or with some drivers also scheduled) completion callback. Since the API allows dmaengine_terminate_all() to be called from atomic context as well as from within a completion callback it is not possible to synchronize to the execution of the completion callback from within dmaengine_terminate_all() itself. This means that a user of the DMAengine API does not know when it is safe to free resources used in the completion callback, which can result in a use-after-free race condition. This patch addresses the issue by introducing an explicit synchronization primitive to the DMAengine API called dmaengine_synchronize(). The existing dmaengine_terminate_all() is deprecated in favor of dmaengine_terminate_sync() and dmaengine_terminate_async(). The former aborts all pending and active transfers and synchronizes to the current context, meaning it will wait until all running completion callbacks have finished. This means it is only possible to call this function from non-atomic context. The later function does not synchronize, but can still be used in atomic context or from within a complete callback. It has to be followed up by dmaengine_synchronize() before a client can free the resources used in a completion callback. In addition to this the semantics of the device_terminate_all() callback are slightly relaxed by this patch. It is now OK for a driver to only schedule the termination of the active transfer, but does not necessarily have to wait until the DMA controller has completely stopped. The driver must ensure though that the controller has stopped and no longer accesses any memory when the device_synchronize() callback returns. This was in part done since most drivers do not pay attention to this anyway at the moment and to emphasize that this needs to be done when the device_synchronize() callback is implemented. But it also helps with implementing support for devices where stopping the controller can require operations that may sleep. Signed-off-by: Lars-Peter Clausen Signed-off-by: Vinod Koul

Documentation: dmaengine: Add DMA_CTRL_REUSE documentation

2015-08-17T08:16:22Z

Signed-off-by: Vinod Koul Acked-by:Robert Jarzmik

Documentation: dmaengine: fix the DMA_CTRL_ACK documentation

2015-08-17T08:16:22Z

As discussed recently the meaning of DMA_CTRL_ACK is that a desc cannot be reused by provider until the client acknowledges receipt, i.e. has has a chance to establish any dependency chains. So update documentation Signed-off-by: Vinod Koul Acked-by:Robert Jarzmik