| Message ID | 1433669307-19478-1-git-send-email-ysato@users.sourceforge.jp (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Simon Horman |
| Headers | show |
Hi Sato-san, Arnd, On Sun, Jun 7, 2015 at 11:28 AM, Yoshinori Sato <ysato@users.sourceforge.jp> wrote: > "earlyprintk" is architecture specific option. > I think general "earlycon" option support more better. Thanks for your patch! I finally gave it a try on shmobile. Sorry for taking that long... Despite claims from a few months ago: On Sun, Mar 22, 2015 at 8:48 PM, Arnd Bergmann <arnd@arndb.de> wrote: > I think a number of people have expressed that they'd rather get rid of the > DEBUG_LL list in the long run, now that we have earlycon working. If we earlycon doesn't seem to be ready on arm. Without "[PATCH v5] ARM: early fixmap support for earlycon" (https://lkml.org/lkml/2015/8/11/532), it hangs in ioremap(), as called from earlycon_map(). > diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c > index 95772cf..6eb82e1 100644 > --- a/drivers/tty/serial/sh-sci.c > +++ b/drivers/tty/serial/sh-sci.c > -#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE > +#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || defined(CONFIG_SERIAL_EARLYCON) > static void serial_console_putchar(struct uart_port *port, int ch) > { > sci_poll_put_char(port, ch); > @@ -2359,9 +2360,12 @@ static void serial_console_write(struct console *co, const char *s, > int locked = 1; > > local_irq_save(flags); > +#if defined(SUPPORT_SYSRQ) > if (port->sysrq) > locked = 0; > - else if (oops_in_progress) > + else > +#endif > + if (oops_in_progress) > locked = spin_trylock(&port->lock); > else > spin_lock(&port->lock); > @@ -2719,6 +2723,66 @@ static void __exit sci_exit(void) > early_platform_init_buffer("earlyprintk", &sci_driver, > early_serial_buf, ARRAY_SIZE(early_serial_buf)); > #endif > +#ifdef CONFIG_SERIAL_EARLYCON > +static struct __init plat_sci_port port_cfg; > + > +static int __init early_console_setup(struct earlycon_device *device, > + int type) > +{ > + if (!device->port.membase) > + return -ENODEV; > + > + device->port.serial_in = sci_serial_in; > + device->port.serial_out = sci_serial_out; > + device->port.type = type; > + memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port)); > + sci_ports[0].cfg = &port_cfg; > + sci_ports[0].cfg->type = type; > + sci_probe_regmap(sci_ports[0].cfg); > + port_cfg.scscr = SCSCR_RE | SCSCR_TE; > + sci_serial_out(&sci_ports[0].port, SCSCR, port_cfg.scscr); > + > + device->con->write = serial_console_write; > + return 0; > +} Earlycon cannot use serial_console_write(), as it takes an uninitialized spinlock(): BUG: spinlock bad magic on CPU#0, swapper/0 lock: sci_ports+0x0/0x35c0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 CPU: 0 PID: 0 Comm: swapper Not tainted 4.2.0-rc6-koelsch-04464-g15cd6b1126aee571 #1525 Hardware name: Generic R8A7791 (Flattened Device Tree) Backtrace: [<c00138b4>] (dump_backtrace) from [<c0013aac>] (show_stack+0x18/0x1c) r6:600001d3 r5:c0e6d268 r4:00000000 r3:00200000 [<c0013a94>] (show_stack) from [<c045fe3c>] (dump_stack+0x78/0x94) [<c045fdc4>] (dump_stack) from [<c006f61c>] (spin_dump+0x80/0x94) r4:00000000 r3:00000000 [<c006f59c>] (spin_dump) from [<c006f65c>] (spin_bug+0x2c/0x30) r5:c0e6d268 r4:c057cfe7 [<c006f630>] (spin_bug) from [<c006f6e8>] (do_raw_spin_lock+0x28/0x198) r5:c0e6d268 r4:c0e6d268 [<c006f6c0>] (do_raw_spin_lock) from [<c0465654>] (_raw_spin_lock+0x3c/0x44) r9:00000000 r8:00000022 r7:00000000 r6:600001d3 r5:c0e6d268 r4:c0e6d268 [<c0465618>] (_raw_spin_lock) from [<c02636cc>] (serial_console_write+0x58/0x134) r4:c0e6d268 [<c0263674>] (serial_console_write) from [<c0072aec>] (call_console_drivers.constprop.25+0xd0/0xf4) r10:c0e4e2c8 r9:c0646010 r8:00000022 r7:00000000 r6:c0e4e2dc r5:c0e2d988 r4:c066a2f0 [<c0072a1c>] (call_console_drivers.constprop.25) from [<c00747a4>] (console_unlock+0x370/0x44c) r9:00000000 r8:00000022 r7:00000006 r6:200001d3 r5:c0e4d908 r4:c0e2e2a4 [<c0074434>] (console_unlock) from [<c00754a4>] (register_console+0x2ac/0x39c) r10:00000001 r9:00000000 r8:c06502d4 r7:c0e2d988 r6:00000000 r5:c0e2d9b8 r4:c066a2f0 [<c00751f8>] (register_console) from [<c061f150>] (of_setup_earlycon+0x9c/0xb0) r9:00000080 r8:c0634039 r7:c061f240 r6:00000000 r5:c066a2f0 r4:ffeff000 [<c061f0b4>] (of_setup_earlycon) from [<c0623668>] (setup_of_earlycon+0x100/0x124) r7:00004288 r6:c063f42c r5:00000000 r4:c0fec000 Fortunately it continues, so I saw the BUG()... Most drivers seem to fix this by having an early_serial_console_write() that only performs the core functionality of serial_console_write(). Alternatively, (sci-specific) early_console_setup() or (generic) register_earlycon() could call spin_lock_init(&device->port.lock); I tried both approaches, and then the kernel doesn't crash anymore. Still, I don't think anything is printed by earlycon: I just see a long delay of a few seconds, presumable until ttySC0 takes over. Calling serial_console_write() explicitly with a test message makes the kernel lock up. Oops... Does FIX_EARLYCON_MEM work? Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index dea1eff..b4c9820 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -741,6 +741,12 @@ config SERIAL_SH_SCI_CONSOLE depends on SERIAL_SH_SCI=y select SERIAL_CORE_CONSOLE +config SERIAL_SH_SCI_EARLYCON + bool "Support for early console on SuperH SCI(F)" + depends on SERIAL_SH_SCI=y + select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON + config SERIAL_SH_SCI_DMA bool "DMA support" depends on SERIAL_SH_SCI && SH_DMAE diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 95772cf..6eb82e1 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -466,7 +466,8 @@ static void sci_port_disable(struct sci_port *sci_port) pm_runtime_put_sync(sci_port->port.dev); } -#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) +#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) \ + || defined(CONFIG_SERIAL_EARLYCON) #ifdef CONFIG_CONSOLE_POLL static int sci_poll_get_char(struct uart_port *port) @@ -2339,7 +2340,7 @@ static void sci_cleanup_single(struct sci_port *port) pm_runtime_disable(port->port.dev); } -#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE +#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || defined(CONFIG_SERIAL_EARLYCON) static void serial_console_putchar(struct uart_port *port, int ch) { sci_poll_put_char(port, ch); @@ -2359,9 +2360,12 @@ static void serial_console_write(struct console *co, const char *s, int locked = 1; local_irq_save(flags); +#if defined(SUPPORT_SYSRQ) if (port->sysrq) locked = 0; - else if (oops_in_progress) + else +#endif + if (oops_in_progress) locked = spin_trylock(&port->lock); else spin_lock(&port->lock); @@ -2719,6 +2723,66 @@ static void __exit sci_exit(void) early_platform_init_buffer("earlyprintk", &sci_driver, early_serial_buf, ARRAY_SIZE(early_serial_buf)); #endif +#ifdef CONFIG_SERIAL_EARLYCON +static struct __init plat_sci_port port_cfg; + +static int __init early_console_setup(struct earlycon_device *device, + int type) +{ + if (!device->port.membase) + return -ENODEV; + + device->port.serial_in = sci_serial_in; + device->port.serial_out = sci_serial_out; + device->port.type = type; + memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port)); + sci_ports[0].cfg = &port_cfg; + sci_ports[0].cfg->type = type; + sci_probe_regmap(sci_ports[0].cfg); + port_cfg.scscr = SCSCR_RE | SCSCR_TE; + sci_serial_out(&sci_ports[0].port, SCSCR, port_cfg.scscr); + + device->con->write = serial_console_write; + return 0; +} +static int __init sci_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + return early_console_setup(device, PORT_SCI); +} +static int __init scif_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + return early_console_setup(device, PORT_SCIF); +} +static int __init scifa_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + return early_console_setup(device, PORT_SCIFA); +} +static int __init scifb_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + return early_console_setup(device, PORT_SCIFB); +} +static int __init hscif_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + return early_console_setup(device, PORT_HSCIF); +} + +EARLYCON_DECLARE(sci, sci_early_console_setup); +OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup); +EARLYCON_DECLARE(scif, scif_early_console_setup); +OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup); +EARLYCON_DECLARE(scifa, scifa_early_console_setup); +OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup); +EARLYCON_DECLARE(scifb, scifb_early_console_setup); +OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup); +EARLYCON_DECLARE(hscif, hscif_early_console_setup); +OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup); +#endif + module_init(sci_init); module_exit(sci_exit);
Hello. "earlyprintk" is architecture specific option. I think general "earlycon" option support more better. Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp> --- drivers/tty/serial/Kconfig | 6 ++++ drivers/tty/serial/sh-sci.c | 70 +++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 73 insertions(+), 3 deletions(-)