Messages in this thread | | | Date | Tue, 30 May 2023 09:09:16 +0800 | Subject | Re: [PATCH v11 10/10] tty: serial: Add Nuvoton ma35d1 serial driver support | From | Jacky Huang <> |
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Dear Jiri,
On 2023/5/24 下午 04:34, Jacky Huang wrote: > Dear Jiri, > > Thanks for your advice. > > On 2023/5/24 下午 03:42, Jiri Slaby wrote: >> On 16. 05. 23, 9:52, Jacky Huang wrote: >>> +static void ma35d1serial_config_port(struct uart_port *port, int >>> flags) >>> +{ >>> + /* >>> + * Driver core for serial ports forces a non-zero value for >>> port type. >>> + * Write an arbitrary value here to accommodate the serial core >>> driver, >>> + * as ID part of UAPI is redundant. >>> + */ >>> + port->type = 1; >> >> So this 1 translates to PORT_8250. Why not to use it directly? Or >> something more saner like PORT_16550A? >> > It's not actually 8250 or 16550A. > Can we add the following definition to > 'include/uapi/linux/serial_core.h' and use PORT_MA35 instead? > > #define PORT_MA35 124 > > >>> +} >>> + >>> +static int ma35d1serial_verify_port(struct uart_port *port, struct >>> serial_struct *ser) >>> +{ >>> + if (port->type != PORT_UNKNOWN && ser->type != 1) >>> + return -EINVAL; >>> + >>> + return 0; >>> +} >> ... >>> +static int __init ma35d1serial_console_setup(struct console *co, >>> char *options) >>> +{ >>> + struct device_node *np = ma35d1serial_uart_nodes[co->index]; >>> + struct uart_ma35d1_port *p = &ma35d1serial_ports[co->index]; >>> + u32 val32[4]; >>> + struct uart_port *port; >>> + int baud = 115200; >>> + int bits = 8; >>> + int parity = 'n'; >>> + int flow = 'n'; >>> + >>> + /* >>> + * Check whether an invalid uart number has been specified, and >> >> You dereferenced ma35d1serial_uart_nodes already. Doesn't >> console=ttyNVT1000 (or something like that) crash the system? >> > > I will add the following check before np = > "ma35d1serial_uart_nodes[co->index]". > > if (co->index < 0 || co->index >= MA35_UART_NR) > return -EINVAL; > > >>> + * if so, search for the first available port that does have >>> + * console support. >> >> The code below doesn't match this comment. > > Yes, I will remove the above comment. > >> >>> + */ >>> + if ((co->index < 0) || (co->index >= MA35_UART_NR)) { >>> + pr_debug("Console Port%x out of range\n", co->index); >>> + return -EINVAL; >>> + } >>> + >>> + if (of_property_read_u32_array(np, "reg", val32, 4) != 0) >> >> Shouldn't that 4 be ARRAY_SIZE(val32) instead? >> > > Will be fixed. > >>> + return -EINVAL; >> >> One \n here please. >> > > Okay, I will add it. > >>> + p->port.iobase = val32[1]; >>> + p->port.membase = ioremap(p->port.iobase, MA35_UART_REG_SIZE); >> >> What if this fails? >> > > I will add a check for the return value. > >>> + p->port.ops = &ma35d1serial_ops; >>> + p->port.line = 0; >>> + p->port.uartclk = MA35_UART_CONSOLE_CLK; >>> + >>> + port = &ma35d1serial_ports[co->index].port; >> >> Isn't this: >> port = &p->port; >> ? >> >> Either use port on all above lines or drop the "port" variable >> completely and use "p->port" below instead. >> > > I will remove port variable and use p->port only. > >>> + >>> + if (options) >>> + uart_parse_options(options, &baud, &parity, &bits, &flow); >>> + >>> + return uart_set_options(port, co, baud, parity, bits, flow); >>> +} >>> + >>> +static struct console ma35d1serial_console = { >>> + .name = "ttyNVT", >>> + .write = ma35d1serial_console_write, >>> + .device = uart_console_device, >>> + .setup = ma35d1serial_console_setup, >>> + .flags = CON_PRINTBUFFER | CON_ENABLED, >>> + .index = -1, >>> + .data = &ma35d1serial_reg, >> >> I don't see console->data used anywhere in the driver? >> > > I will remove it. >
I removed the " .data = &ma35d1serial_reg", but kernel crashed in 'drivers/tty/serial/serial_core.c'.
The variable 'p' of uart_console_device() refer to a NULL, because co->data is NULL. As a result, kernel crashed at 'p->tty_driver'.
struct tty_driver *uart_console_device(struct console *co, int *index) { struct uart_driver *p = co->data; *index = co->index; return p->tty_driver; }
We seem to be unable to remove it. If there are no other considerations, I will keep it in the next version.
>>> +}; >> ... >>> +static int ma35d1serial_probe(struct platform_device *pdev) >>> +{ >>> + struct resource *res_mem; >>> + struct uart_ma35d1_port *up; >>> + int ret = 0; >>> + >>> + if (pdev->dev.of_node) { >>> + ret = of_alias_get_id(pdev->dev.of_node, "serial"); >>> + if (ret < 0) { >>> + dev_err(&pdev->dev, "failed to get alias/pdev id, errno >>> %d\n", ret); >>> + return ret; >>> + } >>> + } >>> + up = &ma35d1serial_ports[ret]; >>> + up->port.line = ret; >>> + res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); >>> + if (!res_mem) >>> + return -ENODEV; >>> + >>> + up->port.iobase = res_mem->start; >>> + up->port.membase = ioremap(up->port.iobase, MA35_UART_REG_SIZE); >> >> Check this too. >> > > Okay, sure. > >>> + up->port.ops = &ma35d1serial_ops; >>> + >>> + spin_lock_init(&up->port.lock); >>> + >>> + up->clk = of_clk_get(pdev->dev.of_node, 0); >>> + if (IS_ERR(up->clk)) { >>> + ret = PTR_ERR(up->clk); >>> + dev_err(&pdev->dev, "failed to get core clk: %d\n", ret); >>> + goto err_iounmap; >>> + } >>> + >>> + ret = clk_prepare_enable(up->clk); >>> + if (ret) >>> + goto err_iounmap; >>> + >>> + if (up->port.line != 0) >>> + up->port.uartclk = clk_get_rate(up->clk); >>> + >>> + ret = platform_get_irq(pdev, 0); >>> + if (ret < 0) >>> + goto err_clk_disable; >>> + >>> + up->port.irq = ret; >>> + up->port.dev = &pdev->dev; >>> + up->port.flags = UPF_BOOT_AUTOCONF; >>> + >>> + platform_set_drvdata(pdev, up); >>> + >>> + ret = uart_add_one_port(&ma35d1serial_reg, &up->port); >>> + if (ret < 0) >>> + goto err_free_irq; >>> + >>> + return 0; >>> + >>> +err_free_irq: >>> + free_irq(up->port.irq, &up->port); >>> + >>> +err_clk_disable: >>> + clk_disable_unprepare(up->clk); >>> + >>> +err_iounmap: >>> + iounmap(up->port.membase); >>> + return ret; >>> +} >> >> thanks, > > Best regards, > Jacky Huang >
Best regards, Jacky Huang
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