linux-toradex.git/drivers/dma/pxa_dma.c, branch v4.9.120

dmaengine: pxa_dma: fix debug message

2016-08-19T10:47:26+00:00

In a very tight timeframe, the debug message in the transfer completion
handler can be misleading, as the completion test report can change just
after the message, and the code flow cannot be deduced from the debug
message.

This is just a cleanup to make debugging easier.

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

dmaengine: pxa_dma: fix hotchain corner case

2016-08-19T06:31:59+00:00

In the case where a descriptor is chained on a running channel, and as
explained in the comment in the code 10 lines above, the success of the
chaining is ensured either if :
 - the DMA is still running
 - or if the chained transfer is completed

Unfortunately the transfer completness test was done on the descriptor
to which the transfer was chained, and not the transfer being chained at
the end, ie. hot-chained.

This corner case is extremely hard to trigger, as usually the DMA chain
is still running, and the first case takes care of returning success of
the hot-chaining. It was seen by hot-chaining several "small transfers"
to a running "big transfer", not in a real-life usecase but by testing
the robustness of the driver.

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

dmaengine: pxa_dma: implement device_synchronize

2016-07-23T10:37:29+00:00

Implement the function which wait until a dma channel is stopped to have
a synchronization point.

This also protects the pxad_remove() from races, such as spurious
interrupts while removing the driver, because :
 - as long as there is one dma channel requested, ie. dma_chan_get() but
   no dma_chan_put(), the try_module_get() of dma_chan_get() prevents
   the remove() routine from running
 - when the last channel is released, ie. the last dma_chan_put() is
   called, if there is a running DMA, pxad_synchronize() is called
 - pxad_synchronize() waits for the channel to stop, which in turn
   ensures on pxa architecture that the interrupt cannot be fired anymore

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

dmaengine: pxa_dma: remove owner assignment

2016-07-23T10:37:26+00:00

debugfs file operations owner is set by core, so remove

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

dmaengine: pxa_dma: remove duplicate const qualifier

2016-04-26T16:29:46+00:00

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

dmaengine: pxa: handle bus errors

2016-04-26T03:33:57+00:00

In the current state, upon bus error the driver will spin endlessly,
relaunching the last tx, which will fail again and again :
 - a bus error happens
 - pxad_chan_handler() is called
 - as PXA_DCSR_STOPSTATE is true, the last non-terminated transaction is
   lauched, which is the one triggering the bus error, as it didn't
   terminate
 - moreover, the STOP interrupt fires a new, as the STOPIRQEN is still
   active

Break this logic by stopping the automatic relaunch of a dma channel
upon a bus error, even if there are still pending issued requests on it.

As dma_cookie_status() seems unable to return DMA_ERROR in its current
form, ie. there seems no way to mark a DMA_ERROR on a per-async-tx
basis, it is chosen in this patch to remember on the channel which
transaction failed, and report it in pxad_tx_status().

It's a bit misleading because if T1, T2, T3 and T4 were queued, and T1
was completed while T2 causes a bus error, the status of T3 and T4 will
be reported as DMA_IN_PROGRESS, while the channel is actually stopped.

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

Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

2016-03-20T21:57:08+00:00

Pull ARM SoC platform updates from Arnd Bergmann:
 "Newly added support for additional SoCs:
   - Axis Artpec-6 SoC family
   - Allwinner A83T SoC
   - Mediatek MT7623
   - NXP i.MX6QP SoC
   - ST Microelectronics stm32f469 microcontroller

  New features:
   - SMP support for Mediatek mt2701
   - Big-endian support for NXP i.MX
   - DaVinci now uses the new DMA engine dma_slave_map
   - OMAP now uses the new DMA engine dma_slave_map
   - earlyprintk support for palmchip uart on mach-tango
   - delay timer support for orion

  Other:
   - Exynos PMU driver moved out to drivers/soc/
   - Various smaller updates for Renesas, Xilinx, PXA, AT91, OMAP,
     uniphier"

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (83 commits)
  ARM: uniphier: rework SMP code to support new System Bus binding
  ARM: uniphier: add missing of_node_put()
  ARM: at91: avoid defining CONFIG_* symbols in source code
  ARM: DRA7: hwmod: Add data for eDMA tpcc, tptc0, tptc1
  ARM: imx: Make reset_control_ops const
  ARM: imx: Do L2 errata only if the L2 cache isn't enabled
  ARM: imx: select ARM_CPU_SUSPEND only for imx6
  dmaengine: pxa_dma: fix the maximum requestor line
  ARM: alpine: select the Alpine MSI controller driver
  ARM: pxa: add the number of DMA requestor lines
  dmaengine: mmp-pdma: add number of requestors
  dma: mmp_pdma: Add the #dma-requests DT property documentation
  ARM: OMAP2+: Add rtc hwmod configuration for ti81xx
  ARM: s3c24xx: Avoid warning for inb/outb
  ARM: zynq: Move early printk virtual address to vmalloc area
  ARM: DRA7: hwmod: Add custom reset handler for PCIeSS
  ARM: SAMSUNG: Remove unused register offset definition
  ARM: EXYNOS: Cleanup header files inclusion
  drivers: soc: samsung: Enable COMPILE_TEST
  MAINTAINERS: Add maintainers entry for drivers/soc/samsung
  ...

dmaengine: pxa_dma: fix cyclic transfers

2016-03-03T15:36:45+00:00

While testing audio with pxa2xx-ac97, underrun were happening while the
user application was correctly feeding the music. Debug proved that the
cyclic transfer is not cyclic, ie. the last descriptor did not loop on
the first.

Another issue is that the descriptor length was always set to 8192,
because of an trivial operator issue.

This was tested on a pxa27x platform.

Fixes: a57e16cf0333 ("dmaengine: pxa: add pxa dmaengine driver")
Reported-by: Vasily Khoruzhick 
Tested-by: Vasily Khoruzhick 
Signed-off-by: Robert Jarzmik 
Signed-off-by: Vinod Koul

dmaengine: pxa_dma: fix the maximum requestor line

2016-02-26T21:57:45+00:00

The current number of requestor lines is limited to 31. This was an
error of a previous commit, as this number is platform dependent, and is
actually :
 - for pxa25x: 40 requestor lines
 - for pxa27x: 75 requestor lines
 - for pxa3xx: 100 requestor lines

The previous testing did not reveal the faulty constant as on pxa[23]xx
platforms, only camera, MSL and USB are above requestor 32, and in these
only the camera has a driver using dma.

Fixes: e87ffbdf0697 ("dmaengine: pxa_dma: fix the no-requestor case")
Signed-off-by: Robert Jarzmik 
Acked-by: Vinod Koul

dmaengine: pxa_dma: declare transfer are reusable

2015-11-16T03:02:16+00:00

As this driver provides a mechanism to reuse transfers, declare it in
its probe function.

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