serial: 8250_bcm2835aux: Allocate uart_8250_port on stack

The bcm2835aux UART driver stores a struct uart_8250_port in its private
data even though it's only passed once to serial8250_register_8250_port()
(which copies all relevant data) and becomes obsolete afterwards.
Allocate the struct on the stack instead for simplicity and to conserve
memory.

The driver also initializes a spinlock in the struct which is never used.
Drop that as well.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Martin Sperl <kernel@martin.sperl.org>
Reviewed-by: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/421d3aed4c34cc8447ac9c26c320961f1b787f11.1579175223.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_bcm2835aux.c b/drivers/tty/serial/8250/8250_bcm2835aux.c
index fb850d0..f03d38e 100644 (file)
--- a/drivers/tty/serial/8250/8250_bcm2835aux.c
+++ b/drivers/tty/serial/8250/8250_bcm2835aux.c
@@ -17,13 +17,13 @@
 #include "8250.h"
 
 struct bcm2835aux_data {
-       struct uart_8250_port uart;
        struct clk *clk;
        int line;
 };
 
 static int bcm2835aux_serial_probe(struct platform_device *pdev)
 {
+       struct uart_8250_port up = { };
        struct bcm2835aux_data *data;
        struct resource *res;
        int ret;
@@ -34,17 +34,14 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
                return -ENOMEM;
 
        /* initialize data */
-       spin_lock_init(&data->uart.port.lock);
-       data->uart.capabilities = UART_CAP_FIFO | UART_CAP_MINI;
-       data->uart.port.dev = &pdev->dev;
-       data->uart.port.regshift = 2;
-       data->uart.port.type = PORT_16550;
-       data->uart.port.iotype = UPIO_MEM;
-       data->uart.port.fifosize = 8;
-       data->uart.port.flags = UPF_SHARE_IRQ |
-                               UPF_FIXED_PORT |
-                               UPF_FIXED_TYPE |
-                               UPF_SKIP_TEST;
+       up.capabilities = UART_CAP_FIFO | UART_CAP_MINI;
+       up.port.dev = &pdev->dev;
+       up.port.regshift = 2;
+       up.port.type = PORT_16550;
+       up.port.iotype = UPIO_MEM;
+       up.port.fifosize = 8;
+       up.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE |
+                       UPF_SKIP_TEST;
 
        /* get the clock - this also enables the HW */
        data->clk = devm_clk_get(&pdev->dev, NULL);
@@ -59,7 +56,7 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
        ret = platform_get_irq(pdev, 0);
        if (ret < 0)
                return ret;
-       data->uart.port.irq = ret;
+       up.port.irq = ret;
 
        /* map the main registers */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -67,15 +64,15 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
                dev_err(&pdev->dev, "memory resource not found");
                return -EINVAL;
        }
-       data->uart.port.membase = devm_ioremap_resource(&pdev->dev, res);
-       ret = PTR_ERR_OR_ZERO(data->uart.port.membase);
+       up.port.membase = devm_ioremap_resource(&pdev->dev, res);
+       ret = PTR_ERR_OR_ZERO(up.port.membase);
        if (ret)
                return ret;
 
        /* Check for a fixed line number */
        ret = of_alias_get_id(pdev->dev.of_node, "serial");
        if (ret >= 0)
-               data->uart.port.line = ret;
+               up.port.line = ret;
 
        /* enable the clock as a last step */
        ret = clk_prepare_enable(data->clk);
@@ -90,10 +87,10 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
         * so we have to multiply the actual clock by 2
         * to get identical baudrates.
         */
-       data->uart.port.uartclk = clk_get_rate(data->clk) * 2;
+       up.port.uartclk = clk_get_rate(data->clk) * 2;
 
        /* register the port */
-       ret = serial8250_register_8250_port(&data->uart);
+       ret = serial8250_register_8250_port(&up);
        if (ret < 0) {
                if (ret != -EPROBE_DEFER)
                        dev_err(&pdev->dev,