Merge v6.12.35linux-rolling-lts

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 46 insertions, 2 deletions

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index aacbed76c7c5..53236e3e4fa4 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -183,6 +183,7 @@ static struct sci_port sci_ports[SCI_NPORTS];
 static unsigned long sci_ports_in_use;
 static struct uart_driver sci_uart_driver;
 static bool sci_uart_earlycon;
+static bool sci_uart_earlycon_dev_probing;
 
 static inline struct sci_port *
 to_sci_port(struct uart_port *uart)
@@ -3404,7 +3405,8 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
 static int sci_probe_single(struct platform_device *dev,
 				      unsigned int index,
 				      struct plat_sci_port *p,
-				      struct sci_port *sciport)
+				      struct sci_port *sciport,
+				      struct resource *sci_res)
 {
 	int ret;
 
@@ -3451,6 +3453,30 @@ static int sci_probe_single(struct platform_device *dev,
 		sciport->port.flags |= UPF_HARD_FLOW;
 	}
 
+	if (sci_uart_earlycon && sci_ports[0].port.mapbase == sci_res->start) {
+		/*
+		 * In case:
+		 * - this is the earlycon port (mapped on index 0 in sci_ports[]) and
+		 * - it now maps to an alias other than zero and
+		 * - the earlycon is still alive (e.g., "earlycon keep_bootcon" is
+		 *   available in bootargs)
+		 *
+		 * we need to avoid disabling clocks and PM domains through the runtime
+		 * PM APIs called in __device_attach(). For this, increment the runtime
+		 * PM reference counter (the clocks and PM domains were already enabled
+		 * by the bootloader). Otherwise the earlycon may access the HW when it
+		 * has no clocks enabled leading to failures (infinite loop in
+		 * sci_poll_put_char()).
+		 */
+		pm_runtime_get_noresume(&dev->dev);
+
+		/*
+		 * Skip cleanup the sci_port[0] in early_console_exit(), this
+		 * port is the same as the earlycon one.
+		 */
+		sci_uart_earlycon_dev_probing = true;
+	}
+
 	return uart_add_one_port(&sci_uart_driver, &sciport->port);
 }
 
@@ -3509,7 +3535,7 @@ static int sci_probe(struct platform_device *dev)
 
 	platform_set_drvdata(dev, sp);
 
-	ret = sci_probe_single(dev, dev_id, p, sp);
+	ret = sci_probe_single(dev, dev_id, p, sp, res);
 	if (ret)
 		return ret;
 
@@ -3666,6 +3692,22 @@ sh_early_platform_init_buffer("earlyprintk", &sci_driver,
 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
 static struct plat_sci_port port_cfg;
 
+static int early_console_exit(struct console *co)
+{
+	struct sci_port *sci_port = &sci_ports[0];
+
+	/*
+	 * Clean the slot used by earlycon. A new SCI device might
+	 * map to this slot.
+	 */
+	if (!sci_uart_earlycon_dev_probing) {
+		memset(sci_port, 0, sizeof(*sci_port));
+		sci_uart_earlycon = false;
+	}
+
+	return 0;
+}
+
 static int __init early_console_setup(struct earlycon_device *device,
 				      int type)
 {
@@ -3683,6 +3725,8 @@ static int __init early_console_setup(struct earlycon_device *device,
 		       SCSCR_RE | SCSCR_TE | port_cfg.scscr);
 
 	device->con->write = serial_console_write;
+	device->con->exit = early_console_exit;
+
 	return 0;
 }
 static int __init sci_early_console_setup(struct earlycon_device *device,