[prev in list] [next in list] [prev in thread] [next in thread]
List: dmaengine
Subject: [PATCH] dmaengine: Clarify cyclic transfer residue documentation
From: Paul Kocialkowski <paul.kocialkowski () bootlin ! com>
Date: 2022-03-31 13:41:14
Message-ID: 20220331134114.703782-1-paul.kocialkowski () bootlin ! com
[Download RAW message or body]
The current documentation for the residue reported in a cyclic transfer
case mentions that the reported residue should be relative to the current
period only. However the definition of DMA_RESIDUE_GRANULARITY_SEGMENT
specifies that the residue should be updated after each period for
a cyclic transfer, which is in direct contradiction.
Moreover the pcm_dmaengine common code uses the residue relative to
the whole cyclic buffer size, not one period.
Correct the residue-related documentation to reflect this.
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
---
Documentation/driver-api/dmaengine/provider.rst | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Documentation/driver-api/dmaengine/provider.rst \
b/Documentation/driver-api/dmaengine/provider.rst index 0072c9c7efd3..d3fa80e333b1 \
100644
--- a/Documentation/driver-api/dmaengine/provider.rst
+++ b/Documentation/driver-api/dmaengine/provider.rst
@@ -457,7 +457,7 @@ supported.
- Should use dma_set_residue to report it
- In the case of a cyclic transfer, it should only take into
- account the current period.
+ account the total size of the cyclic buffer.
- Should return DMA_OUT_OF_ORDER if the device does not support in order
completion and is completing the operation out of order.
--
2.35.1
[prev in list] [next in list] [prev in thread] [next in thread]
Configure |
About |
News |
Add a list |
Sponsored by KoreLogic