[RFC PATCH 2/4] serial: uartps: Use dynamic array for console port

From: Michal Simek
Date: Fri Jul 21 2017 - 05:33:00 EST


Driver console functions are using pointer to static array with fixed
size. There can be only one serial console at the time which is found
by register_console(). register_console() is filling cons->index to
port->line value.

Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
---

drivers/tty/serial/xilinx_uartps.c | 29 ++++++++++++++++++++++++-----
1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 4614349403c1..e6470a3111ce 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -1211,6 +1211,10 @@ static int __init cdns_early_console_setup(struct earlycon_device *device,
OF_EARLYCON_DECLARE(cdns, "cdns,uart-r1p12", cdns_early_console_setup);
OF_EARLYCON_DECLARE(cdns, "xlnx,zynqmp-uart", cdns_early_console_setup);

+
+/* Static pointer to console port */
+static struct uart_port *console_port;
+
/**
* cdns_uart_console_write - perform write operation
* @co: Console handle
@@ -1220,7 +1224,7 @@ static int __init cdns_early_console_setup(struct earlycon_device *device,
static void cdns_uart_console_write(struct console *co, const char *s,
unsigned int count)
{
- struct uart_port *port = &cdns_uart_port[co->index];
+ struct uart_port *port = console_port;
unsigned long flags;
unsigned int imr, ctrl;
int locked = 1;
@@ -1266,15 +1270,13 @@ static void cdns_uart_console_write(struct console *co, const char *s,
*/
static int __init cdns_uart_console_setup(struct console *co, char *options)
{
- struct uart_port *port = &cdns_uart_port[co->index];
+ struct uart_port *port = console_port;
+
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';

- if (co->index < 0 || co->index >= CDNS_UART_NR_PORTS)
- return -EINVAL;
-
if (!port->membase) {
pr_debug("console on " CDNS_UART_TTY_NAME "%i not present\n",
co->index);
@@ -1570,6 +1572,17 @@ static int cdns_uart_probe(struct platform_device *pdev)
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);

+#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
+ /*
+ * If console hasn't been found yet try to assign this port
+ * because it is required to be assigned for console setup function.
+ * If register_console() don't assign value, then console_port pointer
+ * is cleanup.
+ */
+ if (cdns_uart_uart_driver.cons->index == -1)
+ console_port = port;
+#endif
+
rc = uart_add_one_port(&cdns_uart_uart_driver, port);
if (rc) {
dev_err(&pdev->dev,
@@ -1577,6 +1590,12 @@ static int cdns_uart_probe(struct platform_device *pdev)
goto err_out_pm_disable;
}

+#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
+ /* This is not port which is used for console that's why clean it up */
+ if (cdns_uart_uart_driver.cons->index == -1)
+ console_port = NULL;
+#endif
+
return 0;

err_out_pm_disable:
--
1.9.1