spi: davinci: switch to managed controller allocation

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The controller is allocated with the non-managed spi_alloc_host() while
the interrupt is registered with devm_request_threaded_irq().  During
removal, spi_bitbang_stop() only unregisters the controller; the
subsequent spi_controller_put() then frees the controller together with
its embedded davinci_spi devdata, which is the IRQ handler's dev_id.
The devm_request_threaded_irq() release action (free_irq()), which
drains the handler, does not run until after .remove() returns.  A late
or latched interrupt can therefore reach davinci_spi_irq() and
dereference already-freed memory.

Switch to devm_spi_alloc_host() so that the devres LIFO order releases
the controller only after free_irq() has drained the handler, and drop
the now-redundant spi_controller_put() from .remove().  The probe error
path is simplified to direct returns.

The clock is acquired with devm_clk_get_enabled(), which is registered
after the IRQ and thus released before it by the devres LIFO order.
Drain the interrupt explicitly with devm_free_irq() before disabling the
controller so that a late interrupt cannot access the registers of a
clock-gated controller.

This issue was found by an in-house static analysis tool.

Fixes: 5b3bb5963f ("spi: davinci: Use devm_*() functions")
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Link: https://patch.msgid.link/20260719010014.3163356-2-fanwu01@zju.edu.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

...

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Fan Wu 2026-07-19 01:00:14 +00:00 • committed by Mark Brown

parent cb2902c386

commit ea408a05dc

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drivers/spi/spi-davinci.c

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