serial: ucc_uart: limit brg-frequency workaround to PPC32

According to Timur Tabi This bug in older U-Boots is definitely PowerPC-specific So before allowing this driver to be built for platforms other than PPC32, make sure that we don't accept malformed device trees on those other platforms. Suggested-by: Timur Tabi <[email protected]> Reviewed-by: Timur Tabi <[email protected]> Acked-by: Timur Tabi <[email protected]> Signed-off-by: Rasmus Villemoes <[email protected]> Signed-off-by: Li Yang <[email protected]>
tonyvar · Dec 9, 2019 · b0816f8 · b0816f8
1 parent 89ad26f
commit b0816f8
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/drivers/tty/serial/ucc_uart.c b/drivers/tty/serial/ucc_uart.c
@@ -1392,6 +1392,13 @@ static int ucc_uart_probe(struct platform_device *ofdev)
 	if (val)
 		qe_port->port.uartclk = val;
 	else {
+		if (!IS_ENABLED(CONFIG_PPC32)) {
+			dev_err(&ofdev->dev,
+				"invalid brg-frequency in device tree\n");
+			ret = -EINVAL;
+			goto out_np;
+		}
+
 		/*
 		 * Older versions of U-Boot do not initialize the brg-frequency
 		 * property, so in this case we assume the BRG frequency is