Re: [RFC][PATCH] x86: Allow early_printk to use console style param like 115200n8

From: Peter Hurley
Date: Mon Jul 06 2015 - 09:30:18 EST


On 07/04/2015 09:20 AM, Steven Rostedt wrote:
> On Sat, 4 Jul 2015 13:03:59 +0200
> Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
>
>>> + /*
>>> + * In case the input is like console with text after the baud
>>> + * rate. e.g. 115200n8. kstrtoul() will error on such input.
>>> + */
>>> + for (p = s; *p && isdigit(*p); p++)
>>> + ;
>>> + *p = 0;
>>> +
>>> if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
>>> baud = DEFAULT_BAUD;
>>
>>
>
> This was actually one of those cases where I wanted to show that
> keeping the old function around is better than the alternative ;-)
>
> If people say we need to phase out simple_strtoull(), then I wanted to
> show what kinds of hacks we will have if that happens.
>
> I was hoping that someone would point out that simple_strtoull() is a
> better solution. :)

And made worse by the fact that checkpatch flags simple_strtoul* as
obsolete, so people keep submitting junk like above [1] in an effort to
escape the checkpatch warning.

Which I pointed out to Joe back in Feb. (https://lkml.org/lkml/2015/2/25/217)

Regards,
Peter Hurley

[1] or this recent submission

On 05/26/2015 01:12 PM, Peter Hurley wrote:
> On 05/22/2015 12:06 PM, Bin Gao wrote:
>
>> +{
>> + char str[4]; /* max 3 chars, plus a NULL terminator */
>> + char *p = options;
>> + int i = 0;
>> +
>> + while (*p) {
>> + if (i >= 4)
>> + return -EINVAL;
>> +
>> + if (*p == delimiter) {
>> + str[i++] = 0;
>> + if (endp)
>> + *endp = p + 1;
>> + return kstrtou8(str, 10, val); /* decimal, no hex */
>> + }
>> +
>> + str[i++] = *p++;
>> + }
>
> Is all this to avoid using simple_strtoul()?
> If yes, I'd rather you use simple_strtoul() like the rest of the console
> code and ignore the (misguided) advice that simple_strtoul() is obsolete.

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