| Message ID | 7a016ff6-08fc-2811-92e0-7c4603fa8586@sigmadesigns.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 10/04/2017 11:47, Marc Gonzalez wrote: > Define an OF early console for Palmchip UART, which can be enabled > by passing "earlycon" on the boot command line. > > Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com> > --- > drivers/tty/serial/8250/8250_early.c | 24 ++++++++++++++++++++++++ > drivers/tty/serial/8250/8250_port.c | 4 ++-- > 2 files changed, 26 insertions(+), 2 deletions(-) As pointed out by Andreas, Russell, and Robin, specifying the console on the command line is still required. In other words, the stdout-path method is not 100% functional. Testing different boot command-lines, with a kernel that artificially panics in the early stages: "mem=256M" "mem=256M console=ttyS0,115200" prints nothing, as expected. "mem=256M earlycon" does not show the panic message. Hangs after printing: [ 0.014146] Console: colour dummy device 80x30 [ 0.018615] console [tty0] enabled [ 0.022038] bootconsole [palmchip0] disabled "mem=256M console=ttyS0,115200 earlycon" "mem=256M console=ttyS0 earlycon" the panic message does appear, as expected. When I remove the panic, "mem=256M console=ttyS0 earlycon" stops printing kernel messages when the kernel switches the early console off. [ 0.750562] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled [ 0.758976] console [ttyS0] disabled [ 0.762664] 10700.serial: ttyS0 at MMIO 0x10700 (irq = 20, base_baud = 460800) is a Palmchip BK-3103 Therefore, the only 100% functional combination for me is "mem=256M console=ttyS0,115200 earlycon" For completeness, this method shows some "stuttering" in the console handling code: [ 0.000000] earlycon: palmchip0 at MMIO 0x00010700 (options '115200n8') [ 0.000000] bootconsole [palmchip0] enabled [ 0.000000] Kernel command line: mem=256M console=ttyS0,115200 earlycon [ 0.014149] Console: colour dummy device 80x30 [ 0.754670] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled [ 0.763045] console [ttyS0] disabled [ 0.766733] 10700.serial: ttyS0 at MMIO 0x10700 (irq = 20, base_baud = 460800) is a Palmchip BK-3103 [ 0.775969] console [ttyS0] enabled [ 0.775969] console [ttyS0] enabled [ 0.782979] bootconsole [palmchip0] disabled [ 0.782979] bootconsole [palmchip0] disabled This stuttering is likely related to this comment: /* * By unregistering the bootconsoles after we enable the real console * we get the "console xxx enabled" message on all the consoles - * boot consoles, real consoles, etc - this is to ensure that end * users know there might be something in the kernel's log buffer that * went to the bootconsole (that they do not see on the real console) */ In fact, if I add dump_stack() before pr_info("%sconsole [%s%d] enabled\n", pr_info("%sconsole [%s%d] disabled\n", then I get the following output: [ 0.000000] earlycon: palmchip0 at MMIO 0x00010700 (options '115200n8') [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.9.20-1-rc3 #18 [ 0.000000] Hardware name: Sigma Tango DT [ 0.000000] [<c010ed6c>] (unwind_backtrace) from [<c010adc4>] (show_stack+0x10/0x14) [ 0.000000] [<c010adc4>] (show_stack) from [<c02cca50>] (dump_stack+0x84/0x98) [ 0.000000] [<c02cca50>] (dump_stack) from [<c0157b3c>] (register_console+0x224/0x3c8) [ 0.000000] [<c0157b3c>] (register_console) from [<c06189f0>] (of_setup_earlycon+0x1cc/0x1e0) [ 0.000000] [<c06189f0>] (of_setup_earlycon) from [<c061c0a0>] (early_init_dt_scan_chosen_stdout+0x144/0x158) [ 0.000000] [<c061c0a0>] (early_init_dt_scan_chosen_stdout) from [<c0600488>] (do_early_param+0x78/0xbc) [ 0.000000] [<c0600488>] (do_early_param) from [<c0132aec>] (parse_args+0x284/0x3d8) [ 0.000000] [<c0132aec>] (parse_args) from [<c06008a0>] (parse_early_options+0x3c/0x44) [ 0.000000] [<c06008a0>] (parse_early_options) from [<c06008d8>] (parse_early_param+0x30/0x44) [ 0.000000] [<c06008d8>] (parse_early_param) from [<c0603274>] (setup_arch+0x5b8/0xa48) [ 0.000000] [<c0603274>] (setup_arch) from [<c060094c>] (start_kernel+0x5c/0x380) [ 0.000000] [<c060094c>] (start_kernel) from [<8000807c>] (0x8000807c) [ 0.000000] bootconsole [palmchip0] enabled (Lines 2 and 3 are a strange relic of the very first lines output.) [ 0.750471] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled [ 0.758744] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.9.20-1-rc3 #18 [ 0.765317] Hardware name: Sigma Tango DT [ 0.769376] [<c010ed6c>] (unwind_backtrace) from [<c010adc4>] (show_stack+0x10/0x14) [ 0.777162] [<c010adc4>] (show_stack) from [<c02cca50>] (dump_stack+0x84/0x98) [ 0.784430] [<c02cca50>] (dump_stack) from [<c01577e0>] (unregister_console+0xc/0x144) [ 0.792395] [<c01577e0>] (unregister_console) from [<c033cf20>] (uart_remove_one_port+0x1d0/0x1fc) [ 0.801404] [<c033cf20>] (uart_remove_one_port) from [<c033e5c0>] (serial8250_register_8250_port+0x94/0x380) [ 0.811291] [<c033e5c0>] (serial8250_register_8250_port) from [<c0345da8>] (of_platform_serial_probe+0x3f0/0x4ac) [ 0.821614] [<c0345da8>] (of_platform_serial_probe) from [<c0350d88>] (platform_drv_probe+0x34/0x7c) [ 0.830796] [<c0350d88>] (platform_drv_probe) from [<c034f824>] (really_probe+0x1c4/0x254) [ 0.839103] [<c034f824>] (really_probe) from [<c034f978>] (__driver_attach+0xc4/0xc8) [ 0.846972] [<c034f978>] (__driver_attach) from [<c034dd4c>] (bus_for_each_dev+0x68/0x9c) [ 0.855192] [<c034dd4c>] (bus_for_each_dev) from [<c034ee90>] (bus_add_driver+0x1a0/0x218) [ 0.863498] [<c034ee90>] (bus_add_driver) from [<c034fed4>] (driver_register+0x78/0xf8) [ 0.871542] [<c034fed4>] (driver_register) from [<c0101754>] (do_one_initcall+0x44/0x174) [ 0.879770] [<c0101754>] (do_one_initcall) from [<c0600dc4>] (kernel_init_freeable+0x154/0x1e4) [ 0.888516] [<c0600dc4>] (kernel_init_freeable) from [<c04b2fc8>] (kernel_init+0x8/0x10c) [ 0.896736] [<c04b2fc8>] (kernel_init) from [<c0107738>] (ret_from_fork+0x14/0x3c) [ 0.904409] console [ttyS0] disabled [ 0.908072] 10700.serial: ttyS0 at MMIO 0x10700 (irq = 20, base_baud = 460800) is a Palmchip BK-3103 [ 0.917316] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.9.20-1-rc3 #18 [ 0.917316] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.9.20-1-rc3 #18 [ 0.930425] Hardware name: Sigma Tango DT [ 0.930425] Hardware name: Sigma Tango DT [ 0.938477] [<c010ed6c>] (unwind_backtrace) from [<c010adc4>] (show_stack+0x10/0x14) [ 0.938477] [<c010ed6c>] (unwind_backtrace) from [<c010adc4>] (show_stack+0x10/0x14) [ 0.954036] [<c010adc4>] (show_stack) from [<c02cca50>] (dump_stack+0x84/0x98) [ 0.954036] [<c010adc4>] (show_stack) from [<c02cca50>] (dump_stack+0x84/0x98) [ 0.968548] [<c02cca50>] (dump_stack) from [<c0157b3c>] (register_console+0x224/0x3c8) [ 0.968548] [<c02cca50>] (dump_stack) from [<c0157b3c>] (register_console+0x224/0x3c8) [ 0.984458] [<c0157b3c>] (register_console) from [<c033cc98>] (uart_add_one_port+0x424/0x4dc) [ 0.984458] [<c0157b3c>] (register_console) from [<c033cc98>] (uart_add_one_port+0x424/0x4dc) [ 1.001590] [<c033cc98>] (uart_add_one_port) from [<c033e794>] (serial8250_register_8250_port+0x268/0x380) [ 1.001590] [<c033cc98>] (uart_add_one_port) from [<c033e794>] (serial8250_register_8250_port+0x268/0x380) [ 1.020995] [<c033e794>] (serial8250_register_8250_port) from [<c0345da8>] (of_platform_serial_probe+0x3f0/0x4ac) [ 1.020995] [<c033e794>] (serial8250_register_8250_port) from [<c0345da8>] (of_platform_serial_probe+0x3f0/0x4ac) [ 1.041621] [<c0345da8>] (of_platform_serial_probe) from [<c0350d88>] (platform_drv_probe+0x34/0x7c) [ 1.041621] [<c0345da8>] (of_platform_serial_probe) from [<c0350d88>] (platform_drv_probe+0x34/0x7c) [ 1.059975] [<c0350d88>] (platform_drv_probe) from [<c034f824>] (really_probe+0x1c4/0x254) [ 1.059975] [<c0350d88>] (platform_drv_probe) from [<c034f824>] (really_probe+0x1c4/0x254) [ 1.076580] [<c034f824>] (really_probe) from [<c034f978>] (__driver_attach+0xc4/0xc8) [ 1.076580] [<c034f824>] (really_probe) from [<c034f978>] (__driver_attach+0xc4/0xc8) [ 1.092311] [<c034f978>] (__driver_attach) from [<c034dd4c>] (bus_for_each_dev+0x68/0x9c) [ 1.092311] [<c034f978>] (__driver_attach) from [<c034dd4c>] (bus_for_each_dev+0x68/0x9c) [ 1.108742] [<c034dd4c>] (bus_for_each_dev) from [<c034ee90>] (bus_add_driver+0x1a0/0x218) [ 1.108742] [<c034dd4c>] (bus_for_each_dev) from [<c034ee90>] (bus_add_driver+0x1a0/0x218) [ 1.125347] [<c034ee90>] (bus_add_driver) from [<c034fed4>] (driver_register+0x78/0xf8) [ 1.125347] [<c034ee90>] (bus_add_driver) from [<c034fed4>] (driver_register+0x78/0xf8) [ 1.141429] [<c034fed4>] (driver_register) from [<c0101754>] (do_one_initcall+0x44/0x174) [ 1.141429] [<c034fed4>] (driver_register) from [<c0101754>] (do_one_initcall+0x44/0x174) [ 1.157862] [<c0101754>] (do_one_initcall) from [<c0600dc4>] (kernel_init_freeable+0x154/0x1e4) [ 1.157862] [<c0101754>] (do_one_initcall) from [<c0600dc4>] (kernel_init_freeable+0x154/0x1e4) [ 1.175342] [<c0600dc4>] (kernel_init_freeable) from [<c04b2fc8>] (kernel_init+0x8/0x10c) [ 1.175342] [<c0600dc4>] (kernel_init_freeable) from [<c04b2fc8>] (kernel_init+0x8/0x10c) [ 1.191773] [<c04b2fc8>] (kernel_init) from [<c0107738>] (ret_from_fork+0x14/0x3c) [ 1.191773] [<c04b2fc8>] (kernel_init) from [<c0107738>] (ret_from_fork+0x14/0x3c) [ 1.207013] console [ttyS0] enabled [ 1.207013] console [ttyS0] enabled [ 1.214019] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.9.20-1-rc3 #18 [ 1.214019] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.9.20-1-rc3 #18 [ 1.227126] Hardware name: Sigma Tango DT [ 1.227126] Hardware name: Sigma Tango DT [ 1.235175] [<c010ed6c>] (unwind_backtrace) from [<c010adc4>] (show_stack+0x10/0x14) [ 1.235175] [<c010ed6c>] (unwind_backtrace) from [<c010adc4>] (show_stack+0x10/0x14) [ 1.250732] [<c010adc4>] (show_stack) from [<c02cca50>] (dump_stack+0x84/0x98) [ 1.250732] [<c010adc4>] (show_stack) from [<c02cca50>] (dump_stack+0x84/0x98) [ 1.265242] [<c02cca50>] (dump_stack) from [<c01577e0>] (unregister_console+0xc/0x144) [ 1.265242] [<c02cca50>] (dump_stack) from [<c01577e0>] (unregister_console+0xc/0x144) [ 1.281149] [<c01577e0>] (unregister_console) from [<c0157bc8>] (register_console+0x2b0/0x3c8) [ 1.281149] [<c01577e0>] (unregister_console) from [<c0157bc8>] (register_console+0x2b0/0x3c8) [ 1.298455] [<c0157bc8>] (register_console) from [<c033cc98>] (uart_add_one_port+0x424/0x4dc) [ 1.298455] [<c0157bc8>] (register_console) from [<c033cc98>] (uart_add_one_port+0x424/0x4dc) [ 1.315586] [<c033cc98>] (uart_add_one_port) from [<c033e794>] (serial8250_register_8250_port+0x268/0x380) [ 1.315586] [<c033cc98>] (uart_add_one_port) from [<c033e794>] (serial8250_register_8250_port+0x268/0x380) [ 1.334989] [<c033e794>] (serial8250_register_8250_port) from [<c0345da8>] (of_platform_serial_probe+0x3f0/0x4ac) [ 1.334989] [<c033e794>] (serial8250_register_8250_port) from [<c0345da8>] (of_platform_serial_probe+0x3f0/0x4ac) [ 1.355614] [<c0345da8>] (of_platform_serial_probe) from [<c0350d88>] (platform_drv_probe+0x34/0x7c) [ 1.355614] [<c0345da8>] (of_platform_serial_probe) from [<c0350d88>] (platform_drv_probe+0x34/0x7c) [ 1.373968] [<c0350d88>] (platform_drv_probe) from [<c034f824>] (really_probe+0x1c4/0x254) [ 1.373968] [<c0350d88>] (platform_drv_probe) from [<c034f824>] (really_probe+0x1c4/0x254) [ 1.390574] [<c034f824>] (really_probe) from [<c034f978>] (__driver_attach+0xc4/0xc8) [ 1.390574] [<c034f824>] (really_probe) from [<c034f978>] (__driver_attach+0xc4/0xc8) [ 1.406305] [<c034f978>] (__driver_attach) from [<c034dd4c>] (bus_for_each_dev+0x68/0x9c) [ 1.406305] [<c034f978>] (__driver_attach) from [<c034dd4c>] (bus_for_each_dev+0x68/0x9c) [ 1.422735] [<c034dd4c>] (bus_for_each_dev) from [<c034ee90>] (bus_add_driver+0x1a0/0x218) [ 1.422735] [<c034dd4c>] (bus_for_each_dev) from [<c034ee90>] (bus_add_driver+0x1a0/0x218) [ 1.439339] [<c034ee90>] (bus_add_driver) from [<c034fed4>] (driver_register+0x78/0xf8) [ 1.439339] [<c034ee90>] (bus_add_driver) from [<c034fed4>] (driver_register+0x78/0xf8) [ 1.455421] [<c034fed4>] (driver_register) from [<c0101754>] (do_one_initcall+0x44/0x174) [ 1.455421] [<c034fed4>] (driver_register) from [<c0101754>] (do_one_initcall+0x44/0x174) [ 1.471854] [<c0101754>] (do_one_initcall) from [<c0600dc4>] (kernel_init_freeable+0x154/0x1e4) [ 1.471854] [<c0101754>] (do_one_initcall) from [<c0600dc4>] (kernel_init_freeable+0x154/0x1e4) [ 1.489332] [<c0600dc4>] (kernel_init_freeable) from [<c04b2fc8>] (kernel_init+0x8/0x10c) [ 1.489332] [<c0600dc4>] (kernel_init_freeable) from [<c04b2fc8>] (kernel_init+0x8/0x10c) [ 1.505763] [<c04b2fc8>] (kernel_init) from [<c0107738>] (ret_from_fork+0x14/0x3c) [ 1.505763] [<c04b2fc8>] (kernel_init) from [<c0107738>] (ret_from_fork+0x14/0x3c) [ 1.521038] bootconsole [palmchip0] disabled [ 1.521038] bootconsole [palmchip0] disabled Maybe it's possible to detect when console and earlycon are the same, and avoid a pair of unregister/register calls. Regards.
On 10/04/2017 11:47, Marc Gonzalez wrote: > @@ -172,3 +179,20 @@ OF_EARLYCON_DECLARE(omap8250, "ti,omap3-uart", early_omap8250_setup); > OF_EARLYCON_DECLARE(omap8250, "ti,omap4-uart", early_omap8250_setup); > > #endif > + > +#ifdef CONFIG_SERIAL_8250_RT288X > + > +unsigned int au_serial_in(struct uart_port *p, int offset); > +void au_serial_out(struct uart_port *p, int offset, int value); Hmmm, I'm thinking that putting declarations in a .c file might not be a very popular decision... ? Would there be a header, shared by 8250_early.c and 8250_port.c where it might be appropriate to declare au_serial_in/out? > +static int __init early_au_setup(struct earlycon_device *dev, const char *opt) > +{ > + dev->port.serial_in = au_serial_in; > + dev->port.serial_out = au_serial_out; > + dev->port.iotype = UPIO_AU; > + dev->con->write = early_serial8250_write; > + return 0; > +} > +OF_EARLYCON_DECLARE(palmchip, "ralink,rt2880-uart", early_au_setup); > + > +#endif > diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c > index 080d5a59d0a7..1f08d22d1a80 100644 > --- a/drivers/tty/serial/8250/8250_port.c > +++ b/drivers/tty/serial/8250/8250_port.c > @@ -313,7 +313,7 @@ static const s8 au_io_out_map[8] = { > -1, /* UART_SCR (unmapped) */ > }; > > -static unsigned int au_serial_in(struct uart_port *p, int offset) > +unsigned int au_serial_in(struct uart_port *p, int offset) > { > if (offset >= ARRAY_SIZE(au_io_in_map)) > return UINT_MAX; > @@ -323,7 +323,7 @@ static unsigned int au_serial_in(struct uart_port *p, int offset) > return __raw_readl(p->membase + (offset << p->regshift)); > } > > -static void au_serial_out(struct uart_port *p, int offset, int value) > +void au_serial_out(struct uart_port *p, int offset, int value) > { > if (offset >= ARRAY_SIZE(au_io_out_map)) > return; >
[ Trimming CC list to minimize noise ] On 10/04/2017 11:47, Marc Gonzalez wrote: > Define an OF early console for Palmchip UART, which can be enabled > by passing "earlycon" on the boot command line. > > Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com> > --- > drivers/tty/serial/8250/8250_early.c | 24 ++++++++++++++++++++++++ > drivers/tty/serial/8250/8250_port.c | 4 ++-- > 2 files changed, 26 insertions(+), 2 deletions(-) Hello Greg, I'd really like to have earlycon support for this UART in v4.12 Do you see anything wrong with this patch, preventing it from landing? Do you want me to move the function declarations to a header? (If so, which one?) Regards.
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c index 85a12f032402..82fc48eca1df 100644 --- a/drivers/tty/serial/8250/8250_early.c +++ b/drivers/tty/serial/8250/8250_early.c @@ -39,6 +39,7 @@ static unsigned int __init serial8250_early_in(struct uart_port *port, int offset) { + int reg_offset = offset; offset <<= port->regshift; switch (port->iotype) { @@ -52,6 +53,8 @@ static unsigned int __init serial8250_early_in(struct uart_port *port, int offse return ioread32be(port->membase + offset); case UPIO_PORT: return inb(port->iobase + offset); + case UPIO_AU: + return port->serial_in(port, reg_offset); default: return 0; } @@ -59,6 +62,7 @@ static unsigned int __init serial8250_early_in(struct uart_port *port, int offse static void __init serial8250_early_out(struct uart_port *port, int offset, int value) { + int reg_offset = offset; offset <<= port->regshift; switch (port->iotype) { @@ -77,6 +81,9 @@ static void __init serial8250_early_out(struct uart_port *port, int offset, int case UPIO_PORT: outb(value, port->iobase + offset); break; + case UPIO_AU: + port->serial_out(port, reg_offset, value); + break; } } @@ -172,3 +179,20 @@ OF_EARLYCON_DECLARE(omap8250, "ti,omap3-uart", early_omap8250_setup); OF_EARLYCON_DECLARE(omap8250, "ti,omap4-uart", early_omap8250_setup); #endif + +#ifdef CONFIG_SERIAL_8250_RT288X + +unsigned int au_serial_in(struct uart_port *p, int offset); +void au_serial_out(struct uart_port *p, int offset, int value); + +static int __init early_au_setup(struct earlycon_device *dev, const char *opt) +{ + dev->port.serial_in = au_serial_in; + dev->port.serial_out = au_serial_out; + dev->port.iotype = UPIO_AU; + dev->con->write = early_serial8250_write; + return 0; +} +OF_EARLYCON_DECLARE(palmchip, "ralink,rt2880-uart", early_au_setup); + +#endif diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 080d5a59d0a7..1f08d22d1a80 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -313,7 +313,7 @@ static const s8 au_io_out_map[8] = { -1, /* UART_SCR (unmapped) */ }; -static unsigned int au_serial_in(struct uart_port *p, int offset) +unsigned int au_serial_in(struct uart_port *p, int offset) { if (offset >= ARRAY_SIZE(au_io_in_map)) return UINT_MAX; @@ -323,7 +323,7 @@ static unsigned int au_serial_in(struct uart_port *p, int offset) return __raw_readl(p->membase + (offset << p->regshift)); } -static void au_serial_out(struct uart_port *p, int offset, int value) +void au_serial_out(struct uart_port *p, int offset, int value) { if (offset >= ARRAY_SIZE(au_io_out_map)) return;
Define an OF early console for Palmchip UART, which can be enabled by passing "earlycon" on the boot command line. Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com> --- drivers/tty/serial/8250/8250_early.c | 24 ++++++++++++++++++++++++ drivers/tty/serial/8250/8250_port.c | 4 ++-- 2 files changed, 26 insertions(+), 2 deletions(-)