Re: [PATCH] earlyprintk: re-enable earlyprintk calling early_param

From: Sahara
Date: Sun Aug 17 2014 - 22:52:35 EST



2014ë 08ì 15ì 05:34, Andrew Morton ì ê:
On Thu, 14 Aug 2014 19:13:36 +0900 kpark3469@xxxxxxxxx wrote:

From: Sahara <keun-o.park@xxxxxxxxxxxxx>

Although there are many obs_kernel_param and its names are
earlyprintk and also EARLY_PRINTK is also enabled, we could not
see the early_printk output properly until now. This patch
considers earlycon as well as earlyprintk.
Sorry, I just don't understand this description.

What does the patch actually do? What was the kernel behaviour without
the patch and what is the kernel behaviour with the patch?

Without this patch,
- earlycon case -
if early_param("earlycon", ...) is defined and
case #1: if cmdline has "earlycon", then it satisfies the condition "(p->early && parameq(param, p->str))". You can see early_printk().
case #2: if cmdline has "console", then it satisfies the condition "strcmp(param, "console") == 0 && strcmp(p->str, "earlycon") == 0". You can see early_printk().

- earlyprintk case -
if early_param("earlyprintk", ...) is defined and
case #1: if cmdline has "earlyprintk", then it satisfies the condition "(p->early && parameq(param, p->str))". You can see early_printk().
case #2: if cmdline has "console", it does not satisfies the condition, because it only checks out "earlycon" only.

This patch fixes the case #2 problem of earlyprintk.

Thanks.

Best Regards,
Sahara.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/