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    clk: gemini: Fix reset regression · f905293d
    Linus Walleij 提交于
    commit e2860e1f ("serial: 8250_of: Add reset support")
    introduced reset support for the 8250_of driver.
    
    However it unconditionally uses the assert/deassert pair to
    deassert reset on the device at probe and assert it at
    remove. This does not work with systems that have a
    self-deasserting reset controller, such as Gemini, that
    recently added a reset controller.
    
    As a result, the console will not probe on the Gemini with
    this message:
    
    Serial: 8250/16550 driver, 1 ports, IRQ sharing disabled
    of_serial: probe of 42000000.serial failed with error -524
    
    This (-ENOTSUPP) is the error code returned by the
    deassert() operation on self-deasserting reset controllers.
    
    To work around this, implement dummy .assert() and
    .deassert() operations in the Gemini combined clock and
    reset controller. This fixes the issue on this system.
    
    Cc: Joel Stanley <joel@jms.id.au>
    Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Cc: linux-serial@vger.kernel.org
    Fixes: e2860e1f ("serial: 8250_of: Add reset support")
    Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
    Acked-by: NPhilipp Zabel <p.zabel@pengutronix.de>
    Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
    f905293d
clk-gemini.c 12.0 KB