linux-toradex.git/drivers/dma/fsldma.c, branch v3.0.8

dt/fsldma: fix build warning caused by of_platform_device changes

2011-04-11T06:34:38+00:00

Commit 000061245a6797d542854106463b6b20fbdcb12e, "dt/powerpc:
Eliminate users of of_platform_{,un}register_driver" forgot to convert
the type of structure passed into platform_device_register() when it
was converted from of_platform_device_register. Fix it.

Signed-off-by: Ira W. Snyder 
Signed-off-by: Grant Likely

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx

2011-03-23T00:53:13+00:00

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (66 commits)
  avr32: at32ap700x: fix typo in DMA master configuration
  dmaengine/dmatest: Pass timeout via module params
  dma: let IMX_DMA depend on IMX_HAVE_DMA_V1 instead of an explicit list of SoCs
  fsldma: make halt behave nicely on all supported controllers
  fsldma: reduce locking during descriptor cleanup
  fsldma: support async_tx dependencies and automatic unmapping
  fsldma: fix controller lockups
  fsldma: minor codingstyle and consistency fixes
  fsldma: improve link descriptor debugging
  fsldma: use channel name in printk output
  fsldma: move related helper functions near each other
  dmatest: fix automatic buffer unmap type
  drivers, pch_dma: Fix warning when CONFIG_PM=n.
  dmaengine/dw_dmac fix: use readl & writel instead of __raw_readl & __raw_writel
  avr32: at32ap700x: Specify DMA Flow Controller, Src and Dst msize
  dw_dmac: Setting Default Burst length for transfers as 16.
  dw_dmac: Allow src/dst msize & flow controller to be configured at runtime
  dw_dmac: Changing type of src_master and dest_master to u8.
  dw_dmac: Pass Channel Priority from platform_data
  dw_dmac: Pass Channel Allocation Order from platform_data
  ...

fsldma: make halt behave nicely on all supported controllers

2011-03-12T01:52:37+00:00

The original dma_halt() function set the CA (channel abort) bit on both
the 83xx and 85xx controllers. This is incorrect on the 83xx, where this
bit means TEM (transfer error mask) instead. The 83xx doesn't support
channel abort, so we only do this operation on 85xx.

Signed-off-by: Ira W. Snyder 
Signed-off-by: Dan Williams

fsldma: reduce locking during descriptor cleanup

2011-03-12T01:52:37+00:00

This merges the fsl_chan_ld_cleanup() function into the dma_do_tasklet()
function to reduce locking overhead. In the best case, we will be able
to keep the DMA controller busy while we are freeing used descriptors.
In all cases, the spinlock is grabbed two times fewer than before on
each transaction.

Signed-off-by: Ira W. Snyder 
Signed-off-by: Dan Williams

fsldma: support async_tx dependencies and automatic unmapping

2011-03-12T01:52:37+00:00

Previous to this patch, the dma_run_dependencies() function has been
called while holding desc_lock. This function can call tx_submit() for
other descriptors, which may try to re-grab the lock. Avoid this by
moving the descriptors to be cleaned up to a temporary list, and
dropping the lock before cleanup.

At the same time, add support for automatic unmapping of src and dst
buffers, as offered by the DMAEngine API.

Signed-off-by: Ira W. Snyder 
Signed-off-by: Dan Williams

fsldma: fix controller lockups

2011-03-12T01:52:36+00:00

Enabling poisoning in the dmapool API quickly showed that the DMA
controller was fetching descriptors that should not have been in use.
This has caused intermittent controller lockups during testing.

I have been unable to figure out the exact set of conditions which cause
this to happen. However, I believe it is related to the driver using the
hardware registers to track whether the controller is busy or not. The
code can incorrectly decide that the hardware is idle due to lag between
register writes and the hardware actually becoming busy.

To fix this, the driver has been reworked to explicitly track the state
of the hardware, rather than try to guess what it is doing based on the
register values.

This has passed dmatest with 10 threads per channel, 100000 iterations
per thread several times without error. Previously, this would fail
within a few seconds.

Signed-off-by: Ira W. Snyder 
Signed-off-by: Dan Williams

fsldma: minor codingstyle and consistency fixes

2011-03-12T01:52:36+00:00

This fixes some minor violations of the coding style. It also changes
the style of the device_prep_dma_*() function definitions so they are
identical.

Signed-off-by: Ira W. Snyder 
Signed-off-by: Dan Williams

fsldma: improve link descriptor debugging

2011-03-12T01:52:36+00:00

This adds better tracking to link descriptor allocations, callbacks, and
frees. This makes it much easier to track errors with link descriptors.

Signed-off-by: Ira W. Snyder 
Signed-off-by: Dan Williams

fsldma: use channel name in printk output

2011-03-12T01:52:36+00:00

This makes debugging the driver much easier when multiple channels are
running concurrently. In addition, you can see how much descriptor
memory each channel has allocated via the dmapool API in sysfs.

Signed-off-by: Ira W. Snyder 
Signed-off-by: Dan Williams

fsldma: move related helper functions near each other

2011-03-12T01:52:36+00:00

This is a purely cosmetic cleanup. It is nice to have related functions
right next to each other in the code.

Signed-off-by: Ira W. Snyder 
Signed-off-by: Dan Williams