Re: [PATCH] tty: serial: Work around warning backtrace in serial8250_set_defaults

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Dec 05, 2024 at 06:30:33AM -0800, Guenter Roeck wrote:
> Commit 7c7e6c8924e7 ("tty: serial: handle HAS_IOPORT dependencies")
> triggers warning backtraces on a number of platforms which don't support
> IO ports.
> 
> WARNING: CPU: 0 PID: 0 at drivers/tty/serial/8250/8250_port.c:470 serial8250_set_defaults+0x148/0x1d8
> Unsupported UART type 0
> 
> The problem is seen because serial8250_set_defaults() is called for
> all members of the serial8250_ports[] array even if that array is
> not initialized.
> 
> Work around the problem by only displaying the warning if the port
> type is not 0 (UPIO_PORT) or if iobase is set for the port.
> 
> Fixes: 7c7e6c8924e7 ("tty: serial: handle HAS_IOPORT dependencies")
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> Cc: Niklas Schnelle <schnelle@linux.ibm.com>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
> A complete fix will require a sequence of patches, which will have to be
> tested thoroughly and is thus not 6.13 material. This patch doesn't fix
> the underlying problem, but it is good enough for 6.13, or at least not
> worse than 6.12, while at the same time avoiding the warning backtrace.

Thanks, I'll take this for now.

greg k-h