Re: [PATCH v4 24/24] dmaengine: dw-edma: Add trace support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The `edma_irq` tracepoint uses the unexported enum `DW_EDMA_LL_EVENT_STOP` in its `TP_printk()` format string, which breaks offline userspace trace parsing.
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--- Patch [24]: [PATCH v4 24/24] dmaengine: dw-edma: Add trace support ---
commit 6d716b0a3b3953754ece69188d4e3a952b274f83
Author: Frank Li <Frank.Li@nxp.com>

dmaengine: dw-edma: Add trace support

This commit adds tracepoints for the circular LL ring's separate producer
and consumer positions, including LL publication, descriptor operations,
and engine recovery events. The recovery event records configured LL
channels before direction resets.

> diff --git a/drivers/dma/dw-edma/dw-edma-trace.h b/drivers/dma/dw-edma/dw-edma-trace.h
> new file mode 100644
> index 0000000000000..e5b3eb57df065
> --- /dev/null
> +++ b/drivers/dma/dw-edma/dw-edma-trace.h

[ ... ]

> +TRACE_EVENT(edma_irq,
> +	TP_PROTO(struct dw_edma_chan *chan,
> +		 const struct dw_edma_ll_snapshot *snapshot),
> +	TP_ARGS(chan, snapshot),

[ ... ]

> +	TP_printk("chan %u%c event %s head %u done %u total %u idx %d completed %d cookie %d",
> +		  __entry->id,
> +		  __entry->dir ? 'R' : 'W',
> +		  __entry->event == DW_EDMA_LL_EVENT_STOP ? "stop" : "progress",

[Severity: Medium]
Does using the unexported enum DW_EDMA_LL_EVENT_STOP directly in the
TP_printk format string break offline trace parsing?

When this tracepoint is exported to userspace via the events format file, the
literal string DW_EDMA_LL_EVENT_STOP is included in the output. 

Since userspace parsers like libtraceevent cannot resolve unexported kernel
C enums without TRACE_DEFINE_ENUM or __print_symbolic(), they typically fail
to evaluate the expression and may throw an error when parsing the trace data.

> +		  __entry->head,
> +		  __entry->done,
> +		  __entry->total,
> +		  __entry->index,
> +		  __entry->completed_cookie,
> +		  __entry->cookie)
> +);

[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260729143036.3087722-1-den@valinux.co.jp?part=24