• Hans de Goede's avatar
    platform/x86: int3472: Deal with probe ordering issues · 97c2259e
    Hans de Goede authored
    The clk and regulator frameworks expect clk/regulator consumer-devices
    to have info about the consumed clks/regulators described in the device's
    fw_node.
    
    To work around this info missing from the ACPI tables on devices where
    the int3472 driver is used, the int3472 MFD-cell drivers attach info about
    consumers to the clks/regulators when registering these.
    
    This causes problems with the probe ordering wrt drivers for consumers
    of these clks/regulators. Since the lookups are only registered when the
    provider-driver binds, trying to get these clks/regulators before then
    results in a -ENOENT error for clks and a dummy regulator for regulators.
    
    All the sensor ACPI fw-nodes have a _DEP dependency on the INT3472 ACPI
    fw-node, so to work around these probe ordering issues the ACPI core /
    i2c-code does not instantiate the I2C-clients for any ACPI devices
    which have a _DEP dependency on an INT3472 ACPI device until all
    _DEP-s are met.
    
    This relies on acpi_dev_clear_dependencies() getting called by the driver
    for the _DEP-s when they are ready, add a acpi_dev_clear_dependencies()
    call to the discrete.c probe code.
    
    In the tps68470 case calling acpi_dev_clear_dependencies() is already done
    by the acpi_gpiochip_add() call done by the driver for the GPIO MFD cell
    (The GPIO cell is deliberately the last cell created to make sure the
    clk + regulator cells are already instantiated when this happens).
    
    However for proper probe ordering, the clk/regulator cells must not just
    be instantiated the must be fully ready (the clks + regulators must be
    registered with their subsystems).
    
    Add MODULE_SOFTDEP dependencies for the clk and regulator drivers for
    the instantiated MFD-cells so that these are loaded before us and so
    that they bind immediately when the platform-devs are instantiated.
    Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
    Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
    Link: https://lore.kernel.org/r/20211203102857.44539-12-hdegoede@redhat.com
    97c2259e
tps68470.c 5.82 KB