On Mon, Aug 27, 2012 at 09:36:51AM +0200, Dirk Behme wrote: > From: Xinyu Chen <xinyu.chen@xxxxxxxxxxxxx> > > The console feature's write routing is unsafe on SMP with > the startup/shutdown call. > > There could be several consumers of the console > * the kernel printk > * the init process using /dev/kmsg to call printk to show log > * shell, which open /dev/console and write with sys_write() > > The shell goes into the normal uart open/write routing, > but the other two go into the console operations. > The open routing calls imx serial startup, which will write USR1/2 > register without any lock and critical with imx_console_write call. > > Add a spin_lock for startup/shutdown/console_write routing. > > This patch is a port from Freescale's Android kernel. > > Signed-off-by: Xinyu Chen <xinyu.chen@xxxxxxxxxxxxx> > Tested-by: Dirk Behme <dirk.behme@xxxxxxxxxxxx> > CC: Shawn Guo <shawn.guo@xxxxxxxxxx> > CC: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> Acked-by: Shawn Guo <shawn.guo@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
