linux-toradex.git/drivers/dma/at_hdmac.c, branch v3.0.55

dmaengine: at_hdmac: check that each sg data length is non-null

2012-10-02T16:47:37+00:00

commit c456797681db814f4f5b36909e8e94047bf53d9c upstream.

Avoid the construction of a malformed DMA request sent to
the DMA controller.
Log message is for debug only because this condition is unlikely to
append and may only trigger at driver development time.

Signed-off-by: Nicolas Ferre 
Signed-off-by: Vinod Koul 
Signed-off-by: Greg Kroah-Hartman

dmaengine: at_hdmac: fix comment in atc_prep_slave_sg()

2012-10-02T16:47:37+00:00

commit c618a9be0e8c0f36baee2560860a0118a428fb26 upstream.

s/dma_memcpy/slave_sg/ and it is sg length that we are
talking about.

Signed-off-by: Nicolas Ferre 
Signed-off-by: Vinod Koul 
Signed-off-by: Greg Kroah-Hartman

dmaengine: at_hdmac: remove clear-on-read in atc_dostart()

2012-05-07T15:56:33+00:00

commit ed8b0d67f33518a16c6b2450fe5ebebf180c2d04 upstream.

This loop on EBCISR register was designed to clear IRQ sources before enabling
a DMA channel. This register is clear-on-read so a race condition can appear if
another channel is already active and has just finished its transfer.
Removing this read on EBCISR is fixing the issue as there is no case where an IRQ
could be pending: we already make sure that this register is drained at probe()
time and during resume.

Signed-off-by: Nicolas Ferre 
Signed-off-by: Vinod Koul 
Signed-off-by: Greg Kroah-Hartman

at_hdmac: bugfix for enabling channel irq

2012-02-13T19:06:07+00:00

commit bda3a47c886664e86ee14eb79e9072b9e341f575 upstream.

commit 463894705e4089d0ff69e7d877312d496ac70e5b deleted redundant
chan_id and chancnt initialization in dma drivers as this is done
in dma_async_device_register().

However, atc_enable_irq() relied on chan_id set before registering
the device, what left only channel 0 functional for this driver.

This patch introduces atc_enable/disable_chan_irq() as a variant
of atc_enable/disable_irq() with the channel as explicit argument.

Signed-off-by: Nikolaus Voss 
Signed-off-by: Nicolas Ferre 
Signed-off-by: Vinod Koul 
Signed-off-by: Greg Kroah-Hartman

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

2011-05-28T19:35:15+00:00

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (33 commits)
  x86: poll waiting for I/OAT DMA channel status
  maintainers: add dma engine tree details
  dmaengine: add TODO items for future work on dma drivers
  dmaengine: Add API documentation for slave dma usage
  dmaengine/dw_dmac: Update maintainer-ship
  dmaengine: move link order
  dmaengine/dw_dmac: implement pause and resume in dwc_control
  dmaengine/dw_dmac: Replace spin_lock* with irqsave variants and enable submission from callback
  dmaengine/dw_dmac: Divide one sg to many desc, if sg len is greater than DWC_MAX_COUNT
  dmaengine/dw_dmac: set residue as total len in dwc_tx_status if status is !DMA_SUCCESS
  dmaengine/dw_dmac: don't call callback routine in case dmaengine_terminate_all() is called
  dmaengine: at_hdmac: pause: no need to wait for FIFO empty
  pch_dma: modify pci device table definition
  pch_dma: Support new device ML7223 IOH
  pch_dma: Support I2S for ML7213 IOH
  pch_dma: Fix DMA setting issue
  pch_dma: modify for checkpatch
  pch_dma: fix dma direction issue for ML7213 IOH video-in
  dmaengine: at_hdmac: use descriptor chaining help function
  dmaengine: at_hdmac: implement pause and resume in atc_control
  ...

Fix up trivial conflict in drivers/dma/dw_dmac.c

dmaengine: at_hdmac: pause: no need to wait for FIFO empty

2011-05-12T08:25:34+00:00

With the addition of the "pause" feature, an active wait was introduced
to check the "FIFO empty" event. This event was not always happening and
a timout contition was needed.
But, in some cases, this event depend on the peripheral connected to the
channel that is paused: FIFO becomes empty if the peripheral consumes data.
The timeout is pretty difficult to evaluate. Moreover, this check is not
needed.
In conclusion, it seems sensible to entirely remove the checking of
"FIFO empty" status when pausing.

Signed-off-by: Nicolas Ferre 
[commit msg edited for grammer]
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: use descriptor chaining help function

2011-05-09T06:14:13+00:00

A little function helps to chain descriptors:
it is already used in cyclic dma operations, now use it in memcpy and slave_sg
preparation functions.

Signed-off-by: Nicolas Ferre 
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: implement pause and resume in atc_control

2011-05-09T06:12:54+00:00

Pause and resume controls are useful for audio devices. This also returns
correct status from atc_tx_status() in case chan is paused.

Idea from dw_dmac patch by Linus Walleij.

Signed-off-by: Nicolas Ferre 
Acked-by: Linus Walleij 
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: set residue as total len in atc_tx_status

2011-05-09T06:12:45+00:00

If transfer status is !=DMA_SUCCESS, return total transfer len as residue,
instead of zero.

Idea from dw_dmac patch by Viresh Kumar.

Signed-off-by: Nicolas Ferre 
Signed-off-by: Vinod Koul

dmaengine: at_hdmac: specialize AHB interfaces to optimize transfers

2011-05-02T10:12:09+00:00

DMA controller has two AHB interfaces on the SOC internal
matrix.
It is more efficient to specialize each interface as the
access to memory can introduce latencies that are not compatible
with peripheral accesses requirements.

Signed-off-by: Nicolas Ferre 
Signed-off-by: Vinod Koul