linuxkpi: Acquire giant when adding/removing i2c adapters
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Authored by manu on Jun 14 2022, 11:25 AM.

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Reviewers

• hselasky
bz
imp

Group Reviewers

linuxkpi

Commits

rGae3ffc006006: linuxkpi: Acquire giant when adding/removing i2c adapters
rGd87fad36330b: linuxkpi: Acquire giant when adding/removing i2c adapters

Summary

We need Giant as we run in a taskqueue_thread via linux_work.
This fix detaching amdgpu and i915kms.

Sponsored by: Beckhoff Automation GmbH & Co. KG

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Repository

rS FreeBSD src repository - subversion

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No Test Coverage

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Buildable 45965
Build 42853: arc lint + arc unit

Event Timeline

manu created this revision.Jun 14 2022, 11:25 AM

Herald added subscribers: linuxkpi, emaste, imp. · View Herald TranscriptJun 14 2022, 11:25 AM

manu requested review of this revision.Jun 14 2022, 11:25 AM

Harbormaster completed remote builds in B45964: Diff 106896.Jun 14 2022, 11:25 AM

manu added a reviewer: linuxkpi.Jun 14 2022, 11:26 AM

I don't know why I don't need this but looking at the device_delete_child and bus_generic_attach code we need giant.
There is a report of this function failing https://github.com/freebsd/drm-kmod/issues/154 .

If I'm not mistaken you should just bus_topo_lock() and bus_topo_unlock() instead of referring Giant directly!

Use bus_topo_lock/unlock

Harbormaster completed remote builds in B45965: Diff 106897.Jun 14 2022, 11:54 AM

In D35478#804573, @hselasky wrote:

If I'm not mistaken you should just bus_topo_lock() and bus_topo_unlock() instead of referring Giant directly!

Indeed, fixed now.

• hselasky accepted this revision.Jun 14 2022, 11:58 AM

This revision is now accepted and ready to land.Jun 14 2022, 11:58 AM

bz accepted this revision.Jun 14 2022, 4:04 PM

Nothing new in the tree should refer to Giant... I'll have to see if we can poison that to keep it from proliferating.
The bus_topo_* functions were a part of that work, and appear to be used here correctly.

Closed by commit rGd87fad36330b: linuxkpi: Acquire giant when adding/removing i2c adapters (authored by manu). · Explain WhyJun 15 2022, 11:39 AM

This revision was automatically updated to reflect the committed changes.

manu added a commit: rGd87fad36330b: linuxkpi: Acquire giant when adding/removing i2c adapters.

manu added a commit: rGae3ffc006006: linuxkpi: Acquire giant when adding/removing i2c adapters.Jun 21 2022, 3:23 PM