dmaengine: dw-axi-dmac: report per-channel max_burst via device_caps #7011
+11
−1
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
To be discussed: Keep |
|
Apart from the checkpatch indentation complaints, this looks good.
Don't we drop the assignment completely now we have the |
Probably can do, yes. The array should be populated for all channels, so the fallback isn't really needed. I will amend my commit when I take care of checkpatch. |
The patch "dmaengine: dw-axi-dmac: add per-channel AXI burst length
support" programs ARLEN/AWLEN from the snps,axi-max-burst-len array but
still exposed a single max_burst value via dma_get_slave_caps(). As a
result all channels reported 8 even when limited to 4, leading to
warnings:
dma dma2chan5: requested source burst length 8 exceeds supported 4
Add a .device_caps callback to return the correct per-channel max_burst.
This allows drivers like amba-pl011 to clamp burst lengths properly.
Fixes: 0e4e6a0c4f4e ("dmaengine: dw-axi-dmac: add per-channel AXI burst length support")
Signed-off-by: Nicolai Buchwitz <[email protected]>
nbuchwitz
force-pushed
the
devel/fix-axi-dmac
branch
from
e71aa2a to
85a2d41
Compare
|
Thanks! |
popcornmix
added a commit
to raspberrypi/firmware
that referenced
this pull request
Aug 26, 2025
kernel: dmaengine: dw-axi-dmac: report per-channel max_burst via device_caps See: raspberrypi/linux#7011 kernel: Update tpm-slb9673-overlay.dts See: raspberrypi/linux#6993 kernel: Enable Full Screen Splash Images See: raspberrypi/linux#7005 kernel: overlays: Rebuild 5inch display from the 7inch See: raspberrypi/linux#7016
popcornmix
added a commit
to raspberrypi/rpi-firmware
that referenced
this pull request
Aug 26, 2025
kernel: dmaengine: dw-axi-dmac: report per-channel max_burst via device_caps See: raspberrypi/linux#7011 kernel: Update tpm-slb9673-overlay.dts See: raspberrypi/linux#6993 kernel: Enable Full Screen Splash Images See: raspberrypi/linux#7005 kernel: overlays: Rebuild 5inch display from the 7inch See: raspberrypi/linux#7016
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The patch "dmaengine: dw-axi-dmac: add per-channel AXI burst length support" programs ARLEN/AWLEN from the snps,axi-max-burst-len array but still exposed a single max_burst value via dma_get_slave_caps(). As a result all channels reported 8 even when limited to 4, leading to warnings:
dma dma2chan5: requested source burst length 8 exceeds supported 4
Add a .device_caps callback to return the correct per-channel max_burst. This allows drivers like amba-pl011 to clamp burst lengths properly.
Fixes: 0e4e6a0c4f4e ("dmaengine: dw-axi-dmac: add per-channel AXI burst length support") #6994