linux-toradex.git/drivers/dma/imx-sdma.c, branch v4.9.25

dmaengine: imx-sdma - correct the dma transfer residue calculation

2017-03-15T02:02:49+00:00

commit 85f57752b33cf12f1d583f0c10b752292de00abe upstream.

The residue calculation was taking in consideration that dma
transaction status will be always retrieved in the dma callback
used to inform that dma transfer is complete. However this is not
the case for all subsystems that use dma. Some subsystems use a
timer to check the dma status periodically.

Therefore the calculation was updated and residue is calculated
accordingly by a) update the residue calculation taking in
consideration the last used buffer index by using *buf_ptail* variable
and b) chn_real_count (number of bytes transferred) is initialized to
zero, when dma channel is created, to avoid using an uninitialized
value in residue calculation when dma status is checked without
waiting dma complete event.

Signed-off-by: Nandor Han 
Acked-by: Peter Senna Tschudin 
Tested-by: Peter Senna Tschudin 
Tested-by: Marek Vasut 
Signed-off-by: Vinod Koul 
Cc: Fabio Estevam 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'dmaengine-4.9-rc1' of git://git.infradead.org/users/vkoul/slave-dma

2016-10-07T00:13:54+00:00

Pull dmaengine updates from Vinod Koul:
 "This is bit large pile of code which bring in some nice additions:

   - Error reporting: we have added a new mechanism for users of
     dmaenegine to register a callback_result which tells them the
     result of the dma transaction. Right now only one user (ntb) is
     using it.

   - As we discussed on KS mailing list and pointed out NO_IRQ has no
     place in kernel, this also remove NO_IRQ from dmaengine subsystem
     (both arm and ppc users)

   - Support for IOMMU slave transfers and its implementation for arm.

   - To get better build coverage, enable COMPILE_TEST for bunch of
     driver, and fix the warning and sparse complaints on these.

   - Apart from above, usual updates spread across drivers"

* tag 'dmaengine-4.9-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (169 commits)
  async_pq_val: fix DMA memory leak
  dmaengine: virt-dma: move function declarations
  dmaengine: omap-dma: Enable burst and data pack for SG
  DT: dmaengine: rcar-dmac: document R8A7743/5 support
  dmaengine: fsldma: Unmap region obtained by of_iomap
  dmaengine: jz4780: fix resource leaks on error exit return
  dma-debug: fix ia64 build, use PHYS_PFN
  dmaengine: coh901318: fix integer overflow when shifting more than 32 places
  dmaengine: edma: avoid uninitialized variable use
  dma-mapping: fix m32r build warning
  dma-mapping: fix ia64 build, use PHYS_PFN
  dmaengine: ti-dma-crossbar: enable COMPILE_TEST
  dmaengine: omap-dma: enable COMPILE_TEST
  dmaengine: edma: enable COMPILE_TEST
  dmaengine: ti-dma-crossbar: Fix of_device_id data parameter usage
  dmaengine: ti-dma-crossbar: Correct type for of_find_property() third parameter
  dmaengine/ARM: omap-dma: Fix the DMAengine compile test on non OMAP configs
  dmaengine: edma: Rename set_bits and remove unused clear_bits helper
  dmaengine: edma: Use correct type for of_find_property() third parameter
  dmaengine: edma: Fix of_device_id data parameter usage (legacy vs TPCC)
  ...

Merge branch 'topic/imx' into for-linus

2016-10-03T03:47:52+00:00

dmaengine: imx-sdma - update the residue calculation for cyclic channels

2016-08-31T14:27:28+00:00

The calculation of the DMA transaction residue supports only fixed
size data transfers. This implementation is not covering all
operations (e.g. data receiving) when we need to know the exact amount
of bytes transferred.

The loop channels handling was changed to clear the buffer
descriptor errors and use the bd->mode.count to calculate the
residue.

Tested-by: Peter Senna Tschudin 
Acked-by: Peter Senna Tschudin 
Reviewed-by: Vinod Koul 
Signed-off-by: Nandor Han 
Signed-off-by: Greg Kroah-Hartman

dmaengine: imx-sdma - reduce transfer latency for DMA cyclic clients

2016-08-31T14:27:28+00:00

Having the SDMA driver use a tasklet for running the clients
callback introduce some issues:
  - probability to have desynchronized data because of the
    race condition created since the DMA transaction status
    is retrieved only when the callback is executed, leaving
    plenty of time for transaction status to get altered.
  - inter-transfer latency which can leave channels idle.

Move the callback execution, for cyclic channels, to SDMA
interrupt (as advised in `Documentation/dmaengine/provider.txt`)
to (a)reduce the inter-transfer latency and (b) eliminate the
race condition possibility where DMA transaction status might
be changed by the time is read.

The responsibility of the SDMA interrupt latency
is moved to the SDMA clients which case by case should defer
the work to bottom-halves when needed.

Tested-by: Peter Senna Tschudin 
Acked-by: Peter Senna Tschudin 
Reviewed-by: Vinod Koul 
Signed-off-by: Nandor Han 
Signed-off-by: Greg Kroah-Hartman

dmaengine: imx-sdma: Add i.MX7 support

2016-08-31T04:26:54+00:00

Allow i.MX7 to work with the imx-sdma driver.

Signed-off-by: Fabio Estevam 
Tested-by: Stefan Agner 
Signed-off-by: Vinod Koul

dmaengine: imx-sdma: (trivial) fix a typo

2016-08-10T17:35:34+00:00

Signed-off-by: Martin Kaiser 
Signed-off-by: Vinod Koul

dmaengine: imx-sdma: convert callback to helper function

2016-08-08T02:41:39+00:00

This is in preperation of moving to a callback that provides results to the
callback for the transaction. The conversion will maintain current behavior
and the driver must convert to new callback mechanism at a later time in
order to receive results.

Signed-off-by: Dave Jiang 
Reviewed-by: Lars-Peter Clausen 
Signed-off-by: Vinod Koul

dmaengine: imx-sdma: remove assignment never used

2016-07-23T10:37:28+00:00

David reported:
[drivers/dma/imx-sdma.c:769]: (style) Variable 'emi_2_emi' is assigned a value that is never used

Since emi_2_emi is never used afterwards, remove thsi as well

Reported-by: David Binderman 
Cc: Sascha Hauer 
Cc: Fabio Estevam 
Signed-off-by: Vinod Koul

dmaengine: imx-sdma: remove dummy assignment

2016-07-23T10:37:28+00:00

David reported:
drivers/dma/imx-sdma.c:1003]: (style) Same expression on both sides of '|='

ORing with itself yields same result, So remove this

Reported-by: David Binderman 
Cc: Sascha Hauer 
Cc: Fabio Estevam 
Signed-off-by: Vinod Koul