Re: [PATCH] serial: apbuart: Let boards without apbuart boot

From: Miguel Ojeda
Date: Sun May 16 2010 - 04:41:58 EST


On Fri, May 14, 2010 at 4:19 PM, Anton Vorontsov <avorontsov@xxxxxxxxxx> wrote:
> This patch fixes the following oops:
>

I sent a patch that fixes that oops too. It is in mm right now. Please check it.

>  Unable to handle kernel paging request for data at address 0x00000000
>  Faulting instruction address: 0xc016dea8
>  Oops: Kernel access of bad area, sig: 11 [#1]
>  P1020 RDB
>  last sysfs file:
>  NIP: c016dea8 LR: c016dea0 CTR: c0010948
>  REGS: c033fea0 TRAP: 0300   Not tainted  (2.6.34-rc7-00108-g83b5177-dirty)
>  [...]
>  NIP [c016dea8] grlib_apbuart_configure+0xd0/0x3bc
>  LR [c016dea0] grlib_apbuart_configure+0xc8/0x3bc
>  Call Trace:
>  [c033ff50] [c016dea0] grlib_apbuart_configure+0xc8/0x3bc (unreliable)
>  [c033ffa0] [c0316144] apbuart_console_init+0x10/0x34
>  [c033ffb0] [c0314a10] console_init+0x40/0x5c
>
> There's no apbuart on P1020 boards, and what's worse, there's no
> clock-frequency property for it. The driver didn't handle this
> case, which resulted in the oops above. Once we fix this, the
> next oops pops up:
>
>  Unable to handle kernel paging request for data at address 0x00000030
>  Faulting instruction address: 0xc0166ecc
>  Oops: Kernel access of bad area, sig: 11 [#1]
>  P1020 RDB
>  [...]
>  NIP [c0166ecc] uart_set_options+0xd0/0x164
>  LR [c0166e38] uart_set_options+0x3c/0x164
>  Call Trace:
>  [c033fef0] [c0330000] 0xc0330000 (unreliable)
>  [c033ff50] [c03160dc] apbuart_console_setup+0xa8/0x100
>  [c033ff70] [c003d668] register_console+0x338/0x3ec
>  [c033ffa0] [c0316154] apbuart_console_init+0x20/0x34
>  [c033ffb0] [c0314a10] console_init+0x40/0x5c
>  [c033ffc0] [c0300968] start_kernel+0x12c/0x234
>  [c033fff0] [c0000398] skpinv+0x2b0/0x2ec
>
> And that one is because the driver tries to register the console
> even if there were no matches in grlib_apbuart_configure().
>
> While at it, also annotate grlib_apbuart_configure() with __init,
> that fixes several section mismatches:
>
>  Section mismatch in reference from the function
>  grlib_apbuart_configure() to the variable .init.data:apbuart_match
>  The function grlib_apbuart_configure() references the variable
>  __initdata apbuart_match.
>
> Signed-off-by: Anton Vorontsov <avorontsov@xxxxxxxxxx>
> ---
>  drivers/serial/apbuart.c |   19 ++++++++++++++-----
>  1 files changed, 14 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/serial/apbuart.c b/drivers/serial/apbuart.c
> index fe91319..c908734 100644
> --- a/drivers/serial/apbuart.c
> +++ b/drivers/serial/apbuart.c
> @@ -520,11 +520,16 @@ static struct console grlib_apbuart_console = {
>  };
>
>
> -static void grlib_apbuart_configure(void);
> +static int __init grlib_apbuart_configure(void);
>
>  static int __init apbuart_console_init(void)
>  {
> -       grlib_apbuart_configure();
> +       int ret;
> +
> +       ret = grlib_apbuart_configure();
> +       if (ret)
> +               return ret;
> +
>        register_console(&grlib_apbuart_console);
>        return 0;
>  }
> @@ -593,7 +598,7 @@ static struct of_platform_driver grlib_apbuart_of_driver = {
>  };
>
>
> -static void grlib_apbuart_configure(void)
> +static int __init grlib_apbuart_configure(void)
>  {
>        static int enum_done;
>        struct device_node *np, *rp;
> @@ -606,12 +611,14 @@ static void grlib_apbuart_configure(void)
>        struct amba_prom_registers *regs;
>
>        if (enum_done)
> -               return;
> +               return -ENODEV;
>
>        /* Get bus frequency */
>        rp = of_find_node_by_path("/");
>        rp = of_get_next_child(rp, NULL);
>        prop = of_get_property(rp, "clock-frequency", NULL);
> +       if (!prop)
> +               return -ENODEV;
>        freq_khz = *prop;
>
>        line = 0;
> @@ -629,7 +636,7 @@ static void grlib_apbuart_configure(void)
>                        d = *device;
>
>                if (!irqs || !regs)
> -                       return;
> +                       return -ENODEV;
>
>                grlib_apbuart_nodes[line] = np;
>
> @@ -658,6 +665,8 @@ static void grlib_apbuart_configure(void)
>        enum_done = 1;
>
>        grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
> +
> +       return line ? 0 : -ENODEV;
>  }
>
>  static int __init grlib_apbuart_init(void)
> --
> 1.7.0.5
> --
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