tty: serial: msm_serial: Don't require DT aliases

If there isn't a DT alias then of_alias_get_id() will return
-ENODEV. This will cause the msm_serial driver to fail probe,
when we want to keep the previous behavior where we generated a
dynamic line number at probe time. Restore this behavior by
generating a dynamic id if the line number is still negative
after checking for an alias or in the non-DT case looking at the
.id field of the platform device.

Reported-by: Kevin Hilman <khilman@kernel.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index 09364dd8cf3a2ca3f37b0913ccb6271c5f5657a9..d1bc6b6cbc70fad7774d46aadd5c8af165c1381b 100644 (file)
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -1046,14 +1046,14 @@ static int msm_serial_probe(struct platform_device *pdev)
        const struct of_device_id *id;
        int irq, line;
 
-       if (pdev->id == -1)
-               pdev->id = atomic_inc_return(&msm_uart_next_id) - 1;
-
        if (pdev->dev.of_node)
                line = of_alias_get_id(pdev->dev.of_node, "serial");
        else
                line = pdev->id;
 
+       if (line < 0)
+               line = atomic_inc_return(&msm_uart_next_id) - 1;
+
        if (unlikely(line < 0 || line >= UART_NR))
                return -ENXIO;