Re: [PATCH v7 05/10] dmaengine: dw: calculate residue in the status getter

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Low] dmaengine: dw: inaccurate Fixes tag in
  dwc_get_residue_and_status() fix
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commit b5c22abc9b7baff822cfeb84f5f8ea11d403b05b
Author: Serge Semin <fancer.lancer@gmail.com>

> dmaengine: dw: calculate residue in the status getter
>
> Calculate hardware-LLP residue while looking up the requested cookie under
> the channel lock. The scanner and the status getter currently take that
> lock separately, allowing a descriptor to start between the scanner's
> residue update and the status query.
>
> Have dwc_get_hard_llp_desc_residue() return a local residue value from a
> fresh LLP snapshot. Keep the persistent residue field for software-LLP
> block accounting, subtracting the current block's progress when reporting
> status. The descriptor scanner continues to advance software-LLP blocks
> and complete cookies from RAW.XFER, including for polled transfers.
>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Fixes: 3bfb1d20b547 ("dmaengine: Driver for the Synopsys DesignWare DMA controller")
> Cc: stable@vger.kernel.org
> Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
> [james: retain polled completion and software-LLP progress]
> Signed-off-by: James Hilliard <james.hilliard1@gmail.com>

[Severity: Low]
Commit 3bfb1d20b547 ("dmaengine: Driver for the Synopsys DesignWare DMA
controller") did not implement residue calculation or dwc_get_residue().
Calculating hardware-LLP residue in dwc_scan_descriptors() and reading it
under a separate dwc->lock acquisition in dwc_get_residue() was introduced
by commit 4702d5244ca9 ("dw_dmac: return proper residue value"), and
per-descriptor desc->residue lookup via dwc_find_desc() was introduced by
commit b68fd0976286 ("dmaengine: dw: move residue to a descriptor").

Should the Fixes tag instead be:

  Fixes: 4702d5244ca9 ("dw_dmac: return proper residue value")
  Fixes: b68fd0976286 ("dmaengine: dw: move residue to a descriptor")

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Sashiko AI review · https://sashiko.dev/#/patchset/20261115-submit-dw-dma-synchronize-v1-v7-0-8d58f3d49e4d@gmail.com?part=5