diff options
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 48 |
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, |