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    Subject[PATCH 4.4 028/114] serial: amba-pl011: do not request memory region twice
    Date
    From: Lino Sanfilippo <LinoSanfilippo@gmx.de>

    [ Upstream commit d1180405c7b5c7a1c6bde79d5fc24fe931430737 ]

    With commit 3873e2d7f63a ("drivers: PL011: refactor pl011_probe()") the
    function devm_ioremap() called from pl011_setup_port() was replaced with
    devm_ioremap_resource(). Since this function not only remaps but also
    requests the ports io memory region it now collides with the .config_port()
    callback which requests the same region at uart port registration.

    Since devm_ioremap_resource() already claims the memory successfully, the
    request in .config_port() fails.

    Later at uart port deregistration the attempt to release the unclaimed
    memory also fails. The failure results in a “Trying to free nonexistent
    resource" warning.

    Fix these issues by removing the callbacks that implement the redundant
    memory allocation/release. Also make sure that changing the drivers io
    memory base address via TIOCSSERIAL is not allowed any more.

    Fixes: 3873e2d7f63a ("drivers: PL011: refactor pl011_probe()")
    Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
    Link: https://lore.kernel.org/r/20211129174238.8333-1-LinoSanfilippo@gmx.de
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/tty/serial/amba-pl011.c | 27 +++------------------------
    1 file changed, 3 insertions(+), 24 deletions(-)

    diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
    index ecace294dc7e6..75932d68a722f 100644
    --- a/drivers/tty/serial/amba-pl011.c
    +++ b/drivers/tty/serial/amba-pl011.c
    @@ -1944,32 +1944,13 @@ static const char *pl011_type(struct uart_port *port)
    return uap->port.type == PORT_AMBA ? uap->type : NULL;
    }

    -/*
    - * Release the memory region(s) being used by 'port'
    - */
    -static void pl011_release_port(struct uart_port *port)
    -{
    - release_mem_region(port->mapbase, SZ_4K);
    -}
    -
    -/*
    - * Request the memory region(s) being used by 'port'
    - */
    -static int pl011_request_port(struct uart_port *port)
    -{
    - return request_mem_region(port->mapbase, SZ_4K, "uart-pl011")
    - != NULL ? 0 : -EBUSY;
    -}
    -
    /*
    * Configure/autoconfigure the port.
    */
    static void pl011_config_port(struct uart_port *port, int flags)
    {
    - if (flags & UART_CONFIG_TYPE) {
    + if (flags & UART_CONFIG_TYPE)
    port->type = PORT_AMBA;
    - pl011_request_port(port);
    - }
    }

    /*
    @@ -1984,6 +1965,8 @@ static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser)
    ret = -EINVAL;
    if (ser->baud_base < 9600)
    ret = -EINVAL;
    + if (port->mapbase != (unsigned long) ser->iomem_base)
    + ret = -EINVAL;
    return ret;
    }

    @@ -2001,8 +1984,6 @@ static struct uart_ops amba_pl011_pops = {
    .flush_buffer = pl011_dma_flush_buffer,
    .set_termios = pl011_set_termios,
    .type = pl011_type,
    - .release_port = pl011_release_port,
    - .request_port = pl011_request_port,
    .config_port = pl011_config_port,
    .verify_port = pl011_verify_port,
    #ifdef CONFIG_CONSOLE_POLL
    @@ -2032,8 +2013,6 @@ static const struct uart_ops sbsa_uart_pops = {
    .shutdown = sbsa_uart_shutdown,
    .set_termios = sbsa_uart_set_termios,
    .type = pl011_type,
    - .release_port = pl011_release_port,
    - .request_port = pl011_request_port,
    .config_port = pl011_config_port,
    .verify_port = pl011_verify_port,
    #ifdef CONFIG_CONSOLE_POLL
    --
    2.34.1


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