[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <CAGsJ_4yDjDLSPwXubcecmCzpeJTwvGz30-awSAZfC+YtTwB_-w@mail.gmail.com>
Date: Tue, 13 Mar 2012 22:34:18 +0800
From: Barry Song <21cnbao@...il.com>
To: yang gqyang <hustgqyang@...il.com>
Cc: Chenglie He <chengjie.he@...aro.org>,
Robert Lee <rob.lee@...aro.org>, nicolas.pitre@...aro.org,
venki@...gle.com, linaro-dev@...ts.linaro.org,
linux-sh@...r.kernel.org, tony@...mide.com, linux@....linux.org.uk,
ccross@...gle.com, kernel@...tstofly.org, khilman@...com,
kgene.kim@...sung.com, magnus.damm@...il.com,
arnd.bergmann@...aro.org, jon-hunter@...com, len.brown@...el.com,
patches@...aro.org, nsekhar@...com, rjw@...k.pl,
Baohua.Song@....com, linux-omap@...r.kernel.org,
linux@...im.org.za, linux-arm-kernel@...ts.infradead.org,
deepthi@...ux.vnet.ibm.com, g.trinabh@...il.com,
linux-pm@...r.kernel.org, broonie@...nsource.wolfsonmicro.com,
linux-kernel@...r.kernel.org, lethal@...ux-sh.org
Subject: Re: implementing "suspend to ram" on cortex A8 based on linux 3.0.8
hi yang,
在 2012年3月10日 下午10:37,yang gqyang <hustgqyang@...il.com> 写道:
> Thanks for your comment.
> Finally, i find out that i made a mistake. The uart(8250) have not been
> restore after resume, instead, it use the configuration got from boot. The
> uart have not been restored correctly, so that "ls" can not output result
> correctly resulting in it seems that the busybox can not work correctly.
> Now, i still have a question about the uart: why the "printk" can work
> correctly, but the "printf" not?
>
> Before this, i believe that the "printk" work correctly, then the uart
> work ok. but now, i need more reconsidaration about
> the relation between the "printk", "printf" and "uart".
> Can anyone give me some suggestion? Any comment is welcome, thanks a
> lot.
printk use "struct console" driver, it doesn't depend on a device node
for userspace.
printf actaully depends on uart_driver and a /dev/ttySx device node,
stdout and stderr are redirected to /dev/ttySx
uart is just a hardware which can be a tty or kernel console output.
>
>
-barry
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists