PCI/MSI: Clarify pci_free_irq_vectors() usage for managed devices

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Update pci_free_irq_vectors() documentation to clarify that drivers using
pcim_enable_device() must not call pci_free_irq_vectors().

For legacy reasons, pcim_enable_device() switches several normally
un-managed functions into managed mode. Currently, the only function
affected in this way is pcim_setup_msi_release(), which results in
automatic IRQ vector management.

This behavior is dangerous and confusing. Drivers using pcim_enable_device()
should rely on the automatic IRQ vector management and avoid calling
pci_free_irq_vectors() manually.

Suggested-by: Philipp Stanner <phasta@kernel.org>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
[bhelgaas: squash both updates to pci_free_irq_vectors() documentation]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/1770798299-202288-2-git-send-email-shawn.lin@rock-chips.com
Link: https://patch.msgid.link/1770798299-202288-3-git-send-email-shawn.lin@rock-chips.com

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Shawn Lin 2026-02-11 16:24:57 +08:00 • committed by Bjorn Helgaas

parent 6de23f81a5

commit 03e4905402

2 changed files with 10 additions and 2 deletions

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7

Documentation/PCI/msi-howto.rst

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5

drivers/pci/msi/api.c

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