Re: [PATCH 4/8] ARM/etm/sysrq: fix inconstistent help message of sysrq key

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Thu, Mar 07, 2013 at 05:00:23PM +0800, zhangwei(Jovi) wrote:
> Currently help message of /proc/sysrq-trigger highlight its
> upper-case characters, like below:
> 
>       SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E)
>       memory-full-oom-kill(F) kill-all-tasks(I) ...
> 
> this would confuse user trigger sysrq by upper-case character, which is
> inconsistent with the real lower-case character registed key.
> 
> This inconsistent help message will also lead more confused when
> 26 upper-case letters put into use in future.
> 
> This patch fix arm etm sysrq key: "etm buffer dump(v)"

Umm, actually this is wrong.  sysrq doesn't deal with case.

static int sysrq_key_table_key2index(int key)
{
        int retval;

        if ((key >= '0') && (key <= '9'))
                retval = key - '0';
        else if ((key >= 'a') && (key <= 'z'))
                retval = key + 10 - 'a';
        else
                retval = -1;
        return retval;
}

It actually accepts no upper case characters (because they can't be
typed on a PC keyboard with the simple code that is sysrq.)  The sysrq
key combinations there are Alt+Sysrq+key.

All sysrq help messages give the key in parens with a capital letter.
However, there's one change you should make to this anyway - there
should be no spaces in the help message - instead, the spaces should
be the "-" character.  Space is used to separate each sysrq key help
message.

Thanks.