Debug stream debugfs by jsarha · Pull Request #5154 · thesofproject/linux

jsarha · 2024-08-23T09:18:13Z

This commit simply maps the identified debug-stream debug window slot as a debugfs file.

ujfalusi

@jsarha, what I would do is:
rename the ipc4-telemetry.c to ipc4-debugfs.c or something generic and use this to export the raw slots on the needed base.
You can have a single exported function as entry point, you can even move here the sof_ipc4_find_debug_slot_offset_by_type() function...

I know, mtrace is also uses debug slot, but it has been special cased out...

The ipc4-telemetry.h should remain as it is.

jsarha · 2024-08-30T07:26:09Z

@jsarha, what I would do is: rename the ipc4-telemetry.c to ipc4-debugfs.c or something generic and use this to export the raw slots on the needed base. You can have a single exported function as entry point, you can even move here the sof_ipc4_find_debug_slot_offset_by_type() function...

I know, mtrace is also uses debug slot, but it has been special cased out...

The ipc4-telemetry.h should remain as it is.

@ujfalusi I took a shot at this. I still try make sure the zephyr tool can still read the execption file.

jsarha · 2024-09-25T11:25:18Z

@ujfalusi @kv2019i , according to my tests the exception debugfs file works just as well after this change as it did before. That is, neither version works. I have no idea where the problem is, but I am quite sure this version is equivalent to the older version, so I'd hope to get this merged.

lgirdwood · 2024-10-22T14:58:36Z

@jsarha @ujfalusi ping - can we unblock ?

jsarha · 2024-10-23T14:07:52Z

@jsarha @ujfalusi ping - can we unblock ?

This is not as important anymore as before, as the latest debug_stream.py is able to access its debug-window-slot directly using cavstool.py functions. However, I still think the debugfs file is a cleaner way to do this, so I still think this PR is valid.

lgirdwood · 2024-10-23T14:48:14Z

@jsarha @ujfalusi ping - can we unblock ?

This is not as important anymore as before, as the latest debug_stream.py is able to access its debug-window-slot directly using cavstool.py functions. However, I still think the debugfs file is a cleaner way to do this, so I still think this PR is valid.

ok, we can park now and see how well existing tools work - if slow or inconsistent we can continue here.

lgirdwood · 2025-03-19T16:19:54Z

@jsarha @ujfalusi ping - can we unblock ?

This is not as important anymore as before, as the latest debug_stream.py is able to access its debug-window-slot directly using cavstool.py functions. However, I still think the debugfs file is a cleaner way to do this, so I still think this PR is valid.

ok, we can park now and see how well existing tools work - if slow or inconsistent we can continue here.

I think this is useful in situations where no Python runtime is available. @ranj063 @ujfalusi @bardliao lets move forward with this.
@jsarha some conflicts.

jsarha · 2025-06-25T15:02:33Z

Rephrased the first commit message a bit and resurrected ipc4-telemetry.h in the last commit (and updated the message accordingly), which is currently actually used. The code still works with debug_stream.py.

lgirdwood

LGTM.

jsarha · 2025-08-13T12:31:32Z

@lgirdwood should we still get this merged? @ujfalusi should I rebase, the PR getting old, again?

bardliao · 2026-07-27T12:24:29Z

@jsarha Is this PR still valid?

jsarha · 2026-07-27T13:53:41Z

@jsarha Is this PR still valid?

Yes it is, or at least it was. But its not mandatory as debug_stream.py is able to use cavstool.py 's /dev/kmem code to get access to the debug window slot in question.

bardliao · 2026-07-27T14:08:20Z

@jsarha Can you resolve the conflicts? Then we can merge it.

jsarha · 2026-07-30T07:28:27Z

@jsarha Can you resolve the conflicts? Then we can merge it.

@bardliao I've rebased and tested it now.

bardliao · 2026-07-30T14:15:56Z

@lyakh Would you like to approve this PR again? So that we will take your Reviewed-by tag

Copilot

Pull request overview

This PR updates the SOF IPC4 debug-window tooling by exposing the firmware “debug stream” slot (and reworking the existing exception/telemetry slot exposure) via dedicated read-only debugfs nodes.

Changes:

Add a generic IPC4 debug-slot → debugfs mapping helper and use it to create exception and debug_stream debugfs files at FW-ready time.
Remove the older IPC4 telemetry-specific debugfs implementation in favor of the new generic helper.
Add the IPC4 debug-slot type constant for the debug stream slot.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
sound/soc/sof/Makefile	Swap IPC4 telemetry debugfs object for the new generic debug-slot debugfs object.
sound/soc/sof/ipc4.c	Create debugfs nodes for telemetry/exception and debug stream slots; rate-limit missing-slot debug logging.
sound/soc/sof/ipc4-telemetry.h	Drop the now-removed exception debugfs node creation prototype.
sound/soc/sof/ipc4-telemetry.c	Remove telemetry-specific debugfs implementation (replaced by generic helper).
sound/soc/sof/ipc4-priv.h	Add prototype for the new generic debug-slot debugfs node helper.
sound/soc/sof/ipc4-debug-slot-debugfs.c	New generic debug-slot debugfs read implementation.
include/sound/sof/ipc4/header.h	Define `SOF_IPC4_DEBUG_SLOT_DEBUG_STREAM` slot type.

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 	}

-	sof_ipc4_create_exception_debugfs_node(sdev);
+	/* sizeof(u32)is for skiping the first separator magic number */


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🟡 Changes recommended

A critical bounds-check overflow issue and a moderate comment issue remain unresolved.

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Review details

Suppressed comments (2)

sound/soc/sof/ipc4-debug-slot-debugfs.c:52

Descriptor 15 is documented as a partial slot at page 0 + 1024, so this unconditional 4 KiB mailbox read crosses into the next page and exposes unrelated data when the requested type is placed there. Compute the actual slot length from the descriptor and use it both for the read limit and the debugfs file size.

	sof_mailbox_read(sdev, offset + doffset, buf, SOF_IPC4_DEBUG_SLOT_SIZE - doffset);

sound/soc/sof/ipc4.c:743

Fix the missing spacing and the misspelling in this newly added comment.

	/* sizeof(u32)is for skiping the first separator magic number */

Files reviewed: 7/7 changed files
Comments generated: 1
Review effort level: Lite

Adds sof_ipc4_create_debug_slot_ro_debugfs_node() -function for mapping a SOF Intel ipc4 debug window slot as debugfs file. The actual slot is specified with slot_type parameter. The alternatives are defined in include/sound/sof/ipc4/header.h and the slot is found with sof_ipc4_find_debug_slot_offset_by_type(). It also takes the data_offset parameter that specifies where the payload data in the slot begins. The portion that is mapped to the debugfs file is everything after the offset. The last parameter is the name of the file. Signed-off-by: Jyri Sarha <jyri.sarha@linux.intel.com>

Add new debug window slot type for debug-stream protocol. For details see src/debug/debug_stream/debug_stream_slot.h under SOF sources [1]. [1] https://github.com/thesofproject/sof Signed-off-by: Jyri Sarha <jyri.sarha@linux.intel.com>

Maps debug-stream debug window slot as read-only debugfs file with sof_ipc4_create_debug_slot_ro_debugfs_node() -function. Signed-off-by: Jyri Sarha <jyri.sarha@linux.intel.com>

… file Remove sof_ipc4_create_exception_debugfs_node() and ipc4-telemetry.c, and use sof_ipc4_create_debug_slot_ro_debugfs_node() instead for mapping "exception" debugfs file. In running system the SOF_IPC4_DEBUG_SLOT_TELEMETRY is used for telemetry data, but if configured, Zephyr exception data is dumped in the same debug window slot, right after the separator word. Signed-off-by: Jyri Sarha <jyri.sarha@linux.intel.com>

sof_ipc4_find_debug_slot_offset_by_type() prints a dev_dbg message every time a slot type is not found. When debugfs files are polled while the DSP is suspended, this fires on every access and spams the kernel log. Use dev_dbg_ratelimited() to suppress repeated messages. Signed-off-by: Jyri Sarha <jyri.sarha@linux.intel.com>

… file

Copilot

🟡 Changes recommended

The partial descriptor read can expose unrelated data, and the new comment contains a spelling error.

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Review details

Suppressed comments (1)

sound/soc/sof/ipc4.c:744

Correct the spelling in this newly added comment: “skiping” should be “skipping”.

	/* sizeof(u32) is for skiping the first separator magic number */

Files reviewed: 7/7 changed files
Comments generated: 1
Review effort level: Lite

+	buf = kzalloc(SOF_IPC4_DEBUG_SLOT_SIZE - doffset, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	sof_mailbox_read(sdev, offset + doffset, buf, SOF_IPC4_DEBUG_SLOT_SIZE - doffset);


jsarha requested review from bardliao, dbaluta, kv2019i, lgirdwood, plbossart, ranj063 and ujfalusi as code owners August 23, 2024 09:18

jsarha mentioned this pull request Aug 23, 2024

Debug stream thread info pr thesofproject/sof#9398

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plbossart reviewed Aug 23, 2024

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Comment thread sound/soc/sof/ipc4-debug-stream.c Outdated

Comment thread sound/soc/sof/ipc4-debug-stream.c Outdated

Comment thread sound/soc/sof/ipc4-debug-stream.h Outdated

Comment thread sound/soc/sof/ipc4-debug-stream.c Outdated

ujfalusi reviewed Aug 23, 2024

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Comment thread sound/soc/sof/ipc4-debug-stream.c Outdated

ujfalusi reviewed Aug 23, 2024

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Comment thread sound/soc/sof/ipc4-debug-stream.h Outdated

ujfalusi requested changes Aug 23, 2024

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jsarha force-pushed the debug-stream-debugfs branch from 672baba to 68be79a Compare August 30, 2024 07:24

This was referenced Sep 13, 2024

Telemetry2 debugfs #4956

Closed

debug: debug_stream: Access debug slot directly using cavstool.py thesofproject/sof#9498

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ujfalusi previously approved these changes Feb 11, 2025

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lgirdwood previously approved these changes Feb 13, 2025

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jsarha dismissed stale reviews from lgirdwood and ujfalusi via 2bd0077 June 25, 2025 15:00

jsarha force-pushed the debug-stream-debugfs branch from 68be79a to 2bd0077 Compare June 25, 2025 15:00

jsarha requested a review from lyakh as a code owner June 25, 2025 15:00

lgirdwood reviewed Jun 25, 2025

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Comment thread sound/soc/sof/ipc4-pcm.c

lyakh previously approved these changes Jun 26, 2025

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Comment thread sound/soc/sof/ipc4-pcm.c

jsarha mentioned this pull request Feb 10, 2026

Add support for Zephyr debug slot manager and use it by default thesofproject/sof#10500

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jsarha dismissed stale reviews from bardliao and lyakh via 8969765 July 29, 2026 15:21

jsarha force-pushed the debug-stream-debugfs branch from 7d84e22 to 8969765 Compare July 29, 2026 15:21

bardliao previously approved these changes Jul 30, 2026

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lgirdwood previously approved these changes Jul 31, 2026

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Copilot AI lite review requested due to automatic review settings August 13, 2026 16:28

jsarha dismissed stale reviews from lgirdwood and bardliao via cb3e72a August 13, 2026 16:28

Copilot started reviewing on behalf of jsarha August 13, 2026 16:29 View session

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Comment thread sound/soc/sof/ipc4-debug-slot-debugfs.c

Comment thread sound/soc/sof/ipc4.c Outdated

}

sof_ipc4_create_exception_debugfs_node(sdev);

/* sizeof(u32)is for skiping the first separator magic number */

Comment thread sound/soc/sof/ipc4.c Outdated

Copilot AI review requested due to automatic review settings September 14, 2026 17:40

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Comment thread sound/soc/sof/ipc4-debug-slot-debugfs.c Outdated

Jyri Sarha added 6 commits September 14, 2026 20:59

ASoC: SOF: IPC4: Add debug-stream debug slot type

ff69a3a

Add new debug window slot type for debug-stream protocol. For details see src/debug/debug_stream/debug_stream_slot.h under SOF sources [1]. [1] https://github.com/thesofproject/sof Signed-off-by: Jyri Sarha <jyri.sarha@linux.intel.com>

ASoC: SOF: ipc4: Maps debug-stream debug window slot as ro debugfs file

6739f1e

Maps debug-stream debug window slot as read-only debugfs file with sof_ipc4_create_debug_slot_ro_debugfs_node() -function. Signed-off-by: Jyri Sarha <jyri.sarha@linux.intel.com>

ASoC: SOF: ipc4: Use generic function for mapping "exception" debugfs…

3b36e5a

… file

Copilot AI review requested due to automatic review settings September 14, 2026 18:30

jsarha force-pushed the debug-stream-debugfs branch from d9665cc to 3b36e5a Compare September 14, 2026 18:30

Copilot started reviewing on behalf of jsarha September 14, 2026 18:31 View session

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Comment thread sound/soc/sof/ipc4-debug-slot-debugfs.c

Comment on lines +48 to +52

buf = kzalloc(SOF_IPC4_DEBUG_SLOT_SIZE - doffset, GFP_KERNEL);

if (!buf)

return -ENOMEM;

sof_mailbox_read(sdev, offset + doffset, buf, SOF_IPC4_DEBUG_SLOT_SIZE - doffset);

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