linux/drivers/tty
Doug Anderson 9636b755da tty/serial: Prevent drop of DCD on suspend for Tegra UARTs
On Tegra UARTs (except UART1), the DTR / DCD / DSR lines are not
externally accessible.  Instead, the DTR line internally appears to be
looped back to be the input to the DCD and DSR lines.  The net effect
of this is that when we drop DTR (like when we suspend), we'll see DCD
drop too.  ...and when we see DCD drop, we treat that as a hangup.

In order to prevent this hangup from occurring at every sleep, we need
to force DTR to remain high on Tegra UARTs.

This patch uses the mcr_mask / mcr_force fields, which were originally
added for the kludge ALPHA_KLUDGE_MCR.  Using these fields does not
prevent us from removing ALPHA_KLUDGE_MCR--we can just remove the "if"
tests I have added and always init mcr_mask / mcr_force from the
serial8250_config.

NOTE: If we have people that are using UARTA on a Tegra and need to
control DTR, we'll need to either add a separate port type for UARTA
or we'll need to add some tegra-specific code to detect whether the
DTR needs to be left high.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-15 12:13:41 -08:00
..
hvc tty: hvc_dcc: Fix duplicate character inputs 2011-11-15 12:02:13 -08:00
ipwireless
serial tty/serial: Prevent drop of DCD on suspend for Tegra UARTs 2011-11-15 12:13:41 -08:00
vt tty: Add export.h for EXPORT_SYMBOL/THIS_MODULE to exporters 2011-10-31 19:31:28 -04:00
amiserial.c TTY: irq: Remove IRQF_DISABLED 2011-09-22 16:08:57 -07:00
bfin_jtag_comm.c
cyclades.c TTY: irq: Remove IRQF_DISABLED 2011-09-22 16:08:57 -07:00
ehv_bytechan.c drivers/tty: don't use the byte channel handle as a parameter in ehv_bytechan.c 2011-09-26 16:38:43 -07:00
isicom.c TTY: irq: Remove IRQF_DISABLED 2011-09-22 16:08:57 -07:00
Kconfig Merge branch 'for-linus' of git://github.com/richardweinberger/linux 2011-11-02 09:45:39 -07:00
Makefile
moxa.c
moxa.h
mxser.c
mxser.h
n_gsm.c tty/n_gsm: avoid fifo overflow in gsm_dlci_data_output 2011-09-26 16:39:23 -07:00
n_hdlc.c
n_r3964.c
n_tracerouter.c
n_tracesink.c
n_tracesink.h
n_tty.c
nozomi.c
pty.c Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty 2011-10-26 15:11:09 +02:00
rocket_int.h
rocket.c
rocket.h
synclink_gt.c
synclink.c
synclinkmp.c TTY: snyclinkmp: forever loop in tx_load_dma_buffer() 2011-09-29 13:23:33 -07:00
sysrq.c
tty_audit.c
tty_buffer.c
tty_io.c Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty 2011-10-26 15:11:09 +02:00
tty_ioctl.c tty: Support compat_ioctl get/set termios_locked 2011-10-18 14:17:11 -07:00
tty_ldisc.c
tty_mutex.c
tty_port.c