A couple of small improvements to the dmatest documentation.
The first provides a description of what the test actually does. The
second corrects the description of how the test behaves if the channel
parameter is not configured.
v2: Remove Haavard's SoB: from the first patch (Andy S., Vinod K.).
Daniel Thompson (2):
Documentation: dmaengine: Add a description of what dmatest does
Documentation: dmaengine: Correctly describe dmatest with channel
unset
Documentation/driver-api/dmaengine/dmatest.rst | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
base-commit: fa55b7dcdc43c1aa1ba12bca9d2dd4318c2a0dbf
--
2.33.0
Currently it can difficult to determine what dmatest does without
reading the source code. Let's add a description.
The description is taken mostly from the patch header of
commit 4a776f0aa922 ("dmatest: Simple DMA memcpy test client").
It has been edited and updated slightly. Nevertheless the new text was
largely written by Haarvard Skinnemoen and was copied from another
patch, already committed to the kernel, which has Haarvard's SoB:
attached to it.
Signed-off-by: Daniel Thompson <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
---
Documentation/driver-api/dmaengine/dmatest.rst | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/Documentation/driver-api/dmaengine/dmatest.rst b/Documentation/driver-api/dmaengine/dmatest.rst
index ee268d445d38..529cc2cbbb1b 100644
--- a/Documentation/driver-api/dmaengine/dmatest.rst
+++ b/Documentation/driver-api/dmaengine/dmatest.rst
@@ -6,6 +6,16 @@ Andy Shevchenko <[email protected]>
This small document introduces how to test DMA drivers using dmatest module.
+The dmatest module tests DMA memcpy, memset, XOR and RAID6 P+Q operations using
+various lengths and various offsets into the source and destination buffers. It
+will initialize both buffers with a repeatable pattern and verify that the DMA
+engine copies the requested region and nothing more. It will also verify that
+the bytes aren't swapped around, and that the source buffer isn't modified.
+
+The dmatest module can be configured to test a specific channel. It can also
+test multiple channels at the same time, and it can start multiple threads
+competing for the same channel.
+
.. note::
The test suite works only on the channels that have at least one
capability of the following: DMA_MEMCPY (memory-to-memory), DMA_MEMSET
--
2.33.0
Currently the documentation states that channels must be configured before
running the dmatest. This has not been true since commit 6b41030fdc79
("dmaengine: dmatest: Restore default for channel"). Fix accordingly.
Fixes: 6b41030fdc79 ("dmaengine: dmatest: Restore default for channel")
Signed-off-by: Daniel Thompson <[email protected]>
---
Documentation/driver-api/dmaengine/dmatest.rst | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/Documentation/driver-api/dmaengine/dmatest.rst b/Documentation/driver-api/dmaengine/dmatest.rst
index 529cc2cbbb1b..cf9859cd0b43 100644
--- a/Documentation/driver-api/dmaengine/dmatest.rst
+++ b/Documentation/driver-api/dmaengine/dmatest.rst
@@ -153,13 +153,14 @@ Part 5 - Handling channel allocation
Allocating Channels
-------------------
-Channels are required to be configured prior to starting the test run.
-Attempting to run the test without configuring the channels will fail.
+Channels do not need to be configured prior to starting a test run. Attempting
+to run the test without configuring the channels will result in testing any
+channels that are available.
Example::
% echo 1 > /sys/module/dmatest/parameters/run
- dmatest: Could not start test, no channels configured
+ dmatest: No channels configured, continue with any
Channels are registered using the "channel" parameter. Channels can be requested by their
name, once requested, the channel is registered and a pending thread is added to the test list.
--
2.33.0
On 18-11-21, 10:09, Daniel Thompson wrote:
> A couple of small improvements to the dmatest documentation.
>
> The first provides a description of what the test actually does. The
> second corrects the description of how the test behaves if the channel
> parameter is not configured.
Applied, thanks
--
~Vinod