Merge tag 'dmaengine-5.3-rc1' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine updates from Vinod Koul:

 - Add support in dmaengine core to do device node checks for DT devices
   and update bunch of drivers to use that and remove open coding from
   drivers

 - New driver/driver support for new hardware, namely:
     - MediaTek UART APDMA
     - Freescale i.mx7ulp edma2
     - Synopsys eDMA IP core version 0
     - Allwinner H6 DMA

 - Updates to axi-dma and support for interleaved cyclic transfers

 - Greg's debugfs return value check removals on drivers

 - Updates to stm32-dma, hsu, dw, pl330, tegra drivers

* tag 'dmaengine-5.3-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (68 commits)
  dmaengine: Revert "dmaengine: fsl-edma: add i.mx7ulp edma2 version support"
  dmaengine: at_xdmac: check for non-empty xfers_list before invoking callback
  Documentation: dmaengine: clean up description of dmatest usage
  dmaengine: tegra210-adma: remove PM_CLK dependency
  dmaengine: fsl-edma: add i.mx7ulp edma2 version support
  dt-bindings: dma: fsl-edma: add new i.mx7ulp-edma
  dmaengine: fsl-edma-common: version check for v2 instead
  dmaengine: fsl-edma-common: move dmamux register to another single function
  dmaengine: fsl-edma: add drvdata for fsl-edma
  dmaengine: Revert "dmaengine: fsl-edma: support little endian for edma driver"
  dmaengine: rcar-dmac: Reject zero-length slave DMA requests
  dmaengine: dw: Enable iDMA 32-bit on Intel Elkhart Lake
  dmaengine: dw-edma: fix semicolon.cocci warnings
  dmaengine: sh: usb-dmac: Use [] to denote a flexible array member
  dmaengine: dmatest: timeout value of -1 should specify infinite wait
  dmaengine: dw: Distinguish ->remove() between DW and iDMA 32-bit
  dmaengine: fsl-edma: support little endian for edma driver
  dmaengine: hsu: Revert "set HSU_CH_MTSR to memory width"
  dmagengine: pl330: add code to get reset property
  dt-bindings: pl330: document the optional resets property
  ...

1 files changed, 13 insertions, 8 deletions

diff --git a/Documentation/driver-api/dmaengine/dmatest.rst b/Documentation/driver-api/dmaengine/dmatest.rst
index e78d070bb468..ee268d445d38 100644
--- a/Documentation/driver-api/dmaengine/dmatest.rst
+++ b/Documentation/driver-api/dmaengine/dmatest.rst
@@ -44,7 +44,8 @@ Example of usage::
 
     dmatest.timeout=2000 dmatest.iterations=1 dmatest.channel=dma0chan0 dmatest.run=1
 
-Example of multi-channel test usage:
+Example of multi-channel test usage (new in the 5.0 kernel)::
+
     % modprobe dmatest
     % echo 2000 > /sys/module/dmatest/parameters/timeout
     % echo 1 > /sys/module/dmatest/parameters/iterations
@@ -53,15 +54,18 @@ Example of multi-channel test usage:
     % echo dma0chan2 > /sys/module/dmatest/parameters/channel
     % echo 1 > /sys/module/dmatest/parameters/run
 
-Note: the channel parameter should always be the last parameter set prior to
-running the test (setting run=1), this is because upon setting the channel
-parameter, that specific channel is requested using the dmaengine and a thread
-is created with the existing parameters. This thread is set as pending
-and will be executed once run is set to 1. Any parameters set after the thread
-is created are not applied.
+.. note::
+  For all tests, starting in the 5.0 kernel, either single- or multi-channel,
+  the channel parameter(s) must be set after all other parameters. It is at
+  that time that the existing parameter values are acquired for use by the
+  thread(s). All other parameters are shared. Therefore, if changes are made
+  to any of the other parameters, and an additional channel specified, the
+  (shared) parameters used for all threads will use the new values.
+  After the channels are specified, each thread is set as pending. All threads
+  begin execution when the run parameter is set to 1.
 
 .. hint::
-  available channel list could be extracted by running the following command::
+  A list of available channels can be found by running the following command::
 
     % ls -1 /sys/class/dma/
 
@@ -204,6 +208,7 @@ Releasing Channels
 Channels can be freed by setting run to 0.
 
 Example::
+
     % echo dma0chan1 > /sys/module/dmatest/parameters/channel
     dmatest: Added 1 threads using dma0chan1
     % cat /sys/class/dma/dma0chan1/in_use