tty: serial: fsl_lpuart: fix potential bug when using both of_alias_get_id and ida_si...
authorSherry Sun <sherry.sun@nxp.com>
Mon, 21 Mar 2022 11:22:11 +0000 (19:22 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 14 Jun 2022 16:36:03 +0000 (18:36 +0200)
commitb62bbf8a47534c60428f117ba73986e859a409e7
treee85374a6924b77eca60c404d499b180acae8c533
parent923d34ce069e8e51a4d003caa6b66a8cd6ecd0ed
tty: serial: fsl_lpuart: fix potential bug when using both of_alias_get_id and ida_simple_get

[ Upstream commit f398e0aa325c61fa20903833a5b534ecb8e6e418 ]

Now fsl_lpuart driver use both of_alias_get_id() and ida_simple_get() in
.probe(), which has the potential bug. For example, when remove the
lpuart7 alias in dts, of_alias_get_id() will return error, then call
ida_simple_get() to allocate the id 0 for lpuart7, this may confilct
with the lpuart4 which has alias 0.

    aliases {
...
        serial0 = &lpuart4;
        serial1 = &lpuart5;
        serial2 = &lpuart6;
        serial3 = &lpuart7;
    }

So remove the ida_simple_get() in .probe(), return an error directly
when calling of_alias_get_id() fails, which is consistent with other
uart drivers behavior.

Fixes: 3bc3206e1c0f ("serial: fsl_lpuart: Remove the alias node dependence")
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20220321112211.8895-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/tty/serial/fsl_lpuart.c