linux/drivers/tty
Chao Xie cfe275c2db serial: pxa: add spin lock for console write
v3:
Remove empty line

v2:
Move local_irq_save() after clk_prepare_enable()

v1:
At UP mode, when cpu want to print message in kernel, it will invoke
peempt_disable and disable irq. So it is safe for UP mode.
For SMP mode, it is not safe to protect the HW reigsters.
one CPU will run a program which will invoke printf.
another CPU will run a program in kernel that invoke printk.
So when second CPU is trying to printk, it will do
1. save ier register
2. enable uue bit of ier register
3. push buffer to uart fifo
4 .restore ier register
when first CPU want to printf, and it happens between 1 and 4, it will
enable thre bit of ier, and waiting for transmit intterupt. while step 4
will make the ier lost thre bit.
add spin lock here to protect the ier register for console write.

Signed-off-by: Chao Xie <chao.xie@marvell.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-15 15:04:49 -07:00
..
hvc tty: hvc_xen: NULL dereference on allocation failure 2012-05-15 08:48:45 -07:00
ipwireless TTY: ipwireless, use tty from tty_port 2012-04-09 11:30:39 -07:00
serial serial: pxa: add spin lock for console write 2012-06-15 15:04:49 -07:00
vt vt: fix race in vt_waitactive() 2012-06-14 17:10:08 -07:00
amiserial.c tty: Revert the tty locking series, it needs more work 2012-06-02 15:21:43 -07:00
bfin_jtag_comm.c TTY: bfin_jtag_comm, use tty from tty_port 2012-04-09 11:28:18 -07:00
cyclades.c TTY: cyclades, add local pointer for card 2012-06-12 15:50:23 -07:00
ehv_bytechan.c TTY: remove re-assignments to tty_driver members 2012-03-08 11:37:58 -08:00
isicom.c Documentation: remove references to /etc/modprobe.conf 2012-03-30 16:03:15 -07:00
Kconfig tty/powerpc: early udbg consoles can't be modules 2012-02-24 16:11:50 -08:00
Makefile tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driver 2011-08-23 10:32:56 -07:00
moxa.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
moxa.h
mxser.c tty: mxser: local variables should not be exposed globally 2012-05-04 16:42:14 -07:00
mxser.h Fix common misspellings 2011-03-31 11:26:23 -03:00
n_gsm.c TTY: remove re-assignments to tty_driver members 2012-03-08 11:37:58 -08:00
n_hdlc.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
n_r3964.c tty: Revert the tty locking series, it needs more work 2012-06-02 15:21:43 -07:00
n_tracerouter.c n_tracerouter and n_tracesink ldisc additions. 2011-05-13 16:31:00 -07:00
n_tracesink.c n_tracerouter and n_tracesink ldisc additions. 2011-05-13 16:31:00 -07:00
n_tracesink.h n_tracerouter and n_tracesink ldisc additions. 2011-05-13 16:31:00 -07:00
n_tty.c TTY: n_tty, do not dereference user buffer 2012-04-29 22:13:54 -04:00
nozomi.c TTY: remove re-assignments to tty_driver members 2012-03-08 11:37:58 -08:00
pty.c PTY: add tty_port 2012-06-13 17:30:15 -07:00
rocket_int.h
rocket.c TTY: remove unneeded tty->index checks 2012-03-08 11:42:21 -08:00
rocket.h
synclink_gt.c tty: Revert the tty locking series, it needs more work 2012-06-02 15:21:43 -07:00
synclink.c tty: Revert the tty locking series, it needs more work 2012-06-02 15:21:43 -07:00
synclinkmp.c tty: Revert the tty locking series, it needs more work 2012-06-02 15:21:43 -07:00
sysrq.c sysrq: use SEND_SIG_FORCED instead of force_sig() 2012-04-05 15:25:50 -07:00
tty_audit.c tty_audit: fix tty_audit_add_data live lock on audit disabled 2011-03-07 12:04:50 -08:00
tty_buffer.c tty: hold lock across tty buffer finding and buffer filling 2012-04-09 12:12:45 -07:00
tty_io.c TTY: add ports array to tty_driver 2012-06-13 17:30:54 -07:00
tty_ioctl.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
tty_ldisc.c tty: Revert the tty locking series, it needs more work 2012-06-02 15:21:43 -07:00
tty_mutex.c tty: Revert the tty locking series, it needs more work 2012-06-02 15:21:43 -07:00
tty_port.c TTY: add tty_port_register_device helper 2012-06-13 17:30:54 -07:00