ACPI: EC: Avoid _REG disconnect on GPIO IRQ defer

EC event delivery uses either a GPE or, on ACPI reduced hardware
platforms, a GpioInt resource.  The GPE path does not have a provider
lookup that can defer, but acpi_dev_gpio_irq_get() can return
-EPROBE_DEFER for the GpioInt path.

ec_install_handlers() currently installs the EC address space handler and
executes _REG before looking up the GPIO IRQ.  If the GPIO lookup then
defers, acpi_ec_setup() tears the handlers down again.  Removing the EC
address space handler causes ACPICA to execute _REG for disconnect, so
firmware may observe an EC OpRegion connected -> disconnected transition
during one failed probe attempt.

This is observable when the namespace EC reuses a boot EC that has already
installed the EC address space handler.  A deferred namespace EC probe can
disconnect the already usable boot EC OpRegion until a later reprobe
connects it again.  AML that gates EC field accesses on _REG state can
then return fallback values to other drivers during that window.

Prepare the GPIOInt IRQ before publishing EC OpRegion availability to AML.
This leaves the GPE path unchanged, keeps non-deferred GPIO lookup errors
non-fatal as before, and still lets the existing acpi_ec_setup() error
path clean up real handler installation failures.

Fixes: f6484cadbcaf ("ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()")
Signed-off-by: Zhu Ling <zhuling2709@phytium.com.cn>
[ rjw: Added an empty code line after a conditional ]
Link: https://patch.msgid.link/20260715012556.12043-1-zhuling2709@phytium.com.cn
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

0 files changed, 0 insertions, 0 deletions