Some RS-232 devices require DTR to be asserted before they can be used. DTR
is normally asserted in uart_startup() when the port is opened. But we don't
actually open serial console ports, so assert DTR when the port is added.
BTW:
earlyprintk and early_uart are hard coded to set DTR/RTS.
rmk says
The only issue I can think of is the possibility for an attached modem to
auto-answer or maybe even auto-dial before the system is ready for it to do
so. Might have an undesirable cost implication for some running with such a
setup.
Apart from that, I can't think of any other side effect of this specific
patch.
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Andi Kleen <ak@suse.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
serial_core, use pr_debug
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At present, the serial core always allows setserial in userspace to change the
port address, irq and base clock of any serial port. That makes sense for
legacy ISA ports, but not for (say) embedded ns16550 compatible serial ports
at peculiar addresses. In these cases, the kernel code configuring the ports
must know exactly where they are, and their clocking arrangements (which can
be unusual on embedded boards). It doesn't make sense for userspace to change
these settings.
Therefore, this patch defines a UPF_FIXED_PORT flag for the uart_port
structure. If this flag is set when the serial port is configured, any
attempts to alter the port's type, io address, irq or base clock with
setserial are ignored.
In addition this patch uses the new flag for on-chip serial ports probed in
arch/powerpc/kernel/legacy_serial.c, and for other hard-wired serial ports
probed by drivers/serial/of_serial.c.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Serial driver patch for the PMC-Sierra MSP71xx devices.
There are three different fixes:
1 Fix for DesignWare APB THRE errata: In brief, this is a non-standard
16550 in that the THRE interrupt will not re-assert itself simply by
disabling and re-enabling the THRI bit in the IER, it is only re-enabled
if a character is actually sent out.
It appears that the "8250-uart-backup-timer.patch" in the "mm" tree
also fixes it so we have dropped our initial workaround. This patch now
needs to be applied on top of that "mm" patch.
2 Fix for Busy Detect on LCR write: The DesignWare APB UART has a feature
which causes a new Busy Detect interrupt to be generated if it's busy
when the LCR is written. This fix saves the value of the LCR and
rewrites it after clearing the interrupt.
3 Workaround for interrupt/data concurrency issue: The SoC needs to
ensure that writes that can cause interrupts to be cleared reach the UART
before returning from the ISR. This fix reads a non-destructive register
on the UART so the read transaction completion ensures the previously
queued write transaction has also completed.
Signed-off-by: Marc St-Jean <Marc_St-Jean@pmc-sierra.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since serial devices are powered down when not in use and some of those
devices cannot be accessed when powered down, we need to enable power
around calls to get_mcrtl() when dumping port state via uart_line_info().
This resolves hangs observed on some machines while reading serial device
registers when a port is powered off.
Signed-off-by: George G. Davis <gdavis@mvista.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the grungy swap all the occurrences in the right places patch that
goes with the updates. At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs
If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.
If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)
Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia
[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As part of an SMP cleanliness pass over UML, I consted a bunch of
structures in order to not have to document their locking. One of these
structures was a struct tty_operations. In order to const it in UML
without introducing compiler complaints, the declaration of
tty_set_operations needs to be changed, and then all of its callers need to
be fixed.
This patch declares all struct tty_operations in the tree as const. In all
cases, they are static and used only as input to tty_set_operations. As an
extra check, I ran an i386 allyesconfig build which produced no extra
warnings.
53 drivers are affected. I checked the history of a bunch of them, and in
most cases, there have been only a handful of maintenance changes in the
last six months. serial_core.c was the busiest one that I looked at.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A serial card might have been removed when the system is resumed.
This results in a suspended port being shut down, which results in
the ports shutdown method being called twice in a row. This causes
BUGs. Avoid this by tracking the suspended state separately from
the initialised state.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix the issue of returning 0 even in case of error from uart_set_info
function. Now it returns the error EBUSY when it can not set new port.
Signed-off-by: Ram Gupta <r.gupta@astronautics.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
/proc/tty/driver/serial incorrectly claims that UARTs having iotype of
UPIO_MEM32, UPIO_AU, or UPIO_TSI are I/O mapped.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Hack uart_suspend_port() and uart_resume_port() so that serial console
ports are not suspended if CONFIG_DISABLE_CONSOLE_SUSPEND is set.
This makes it possible to debug the suspend and resume routines of all
device drivers as well as the lowest-level swsusp code with the help of the
serial console.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
uart_match_port() always fails with UPIO_MEM32, UPIO_AU, and UPIO_TSI cases.
Since they match to the memory mapped UARTs, they should be handled just like
UPIO_MEM case.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The following patch gets rid of CONFIG_TSI108_BRIDGE. I add UPIO_TSI to
handle IIR and IER register in serial_in and serial_out.
(1) the reason to rewrite serial_in:
TSI108 rev Z1 version ERRATA. Reading the UART's Interrupt
Identification Register (IIR) clears the Transmit Holding Register
Empty (THRE) and Transmit buffer Empty (TEMP) interrupts even if they
are not enabled in the Interrupt Enable Register (IER). This leads to
loss of the interrupts. Interrupts are not cleared when reading UART
registers as 32-bit word.
(2) the reason to rewrite serial_out:
Check for UART_IER_UUE bit in the autoconfig routine. This section
of autoconfig is excluded for Tsi108/109 because bits 7 and 6 are
reserved for internal use. They are R/W bits. In addition to
incorrect identification, changing these bits (from 00) will make
Tsi108/109 UART non-functional.
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-serial:
[SERIAL] Ensure 8250_pci quirks are not marked __devinit
[SERIAL] Convert fifosize to an unsigned int
Teach special (dual-initialized) locking code to the lock validator. Has no
effect on non-lockdep kernels.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some UARTs have more than 255 bytes of FIFO, which can't be
represented by an unsigned char. Change the kernel's internal
structure to be an unsigned int, but still export an unsigned char
via the TIOCGSERIAL ioctl. If the TIOCSSERIAL ioctl provides a
fifo size of 0, assume this means "don't change" otherwise we'll
corrupt the larger fifo sizes.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
I've always found this flag confusing. Now that devfs is no longer around, it
has been renamed, and the documentation for when this flag should be used has
been updated.
Also fixes all drivers that use this flag.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Patch from Andrew Victor
The serial_core already manages the power state of the UARTs, and
therefore it shouldn't suspend a UART which was previously suspended.
This patch modifies serial_core only call the UART-specific
power-management function if the PM state is actually changing.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The locking for the uart_port is over complicated, and can be
simplified if we introduce a flag to indicate that a port is "dead"
and will be removed.
This also helps the validator because it removes a case of non-nested
unlock ordering.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Glen Turner reported that writing LFCR rather than the more
traditional CRLF causes issues with some terminals.
Since this aflicts many serial drivers, extract the common code
to a library function (uart_console_write) and arrange for each
driver to supply a "putchar" function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We're presently getting oopses because Bluetooth (and possibly other) drivers
are calling core functions after things have been shut down.
So rather than oopsing, let's drop a warning then take avoiding action, so the
machine survives. Once all the sub-drivers are fixed up we can remove the
take-avoiding-action part.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It seems serial_core intend to initialize port->lock just once for each
ports. This is done in uart_set_options() for console, and in
uart_add_one_port() for other ports. But there is a case the port->lock is
not initialized by serial_core. If the setup function for the console was
failed, it will not call uart_set_options() but the port is marked as
console (uart_console(port) returns 1). It can happen if console was PCI
port which can not detected at the time of register_console.
This patch is to initialize port->lock for such console port. With this
change, most of spin_lock_init() (some of them are labeled "Temporary
fix.") in low-level serial drivers can be omitted.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Same reasoning as commit 747c8a5594
but this time we're making uart_port flags a bitwise type - not
all of these flags correspond with the old ASYNC_ flags, so there
is the possibility for bugs if the wrong ASYNC_* constants are
used. Always use UPF_* constants for uart_port->flags.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
semaphore to mutex conversion.
the conversion was generated via scripts, and the result was validated
automatically via a script as well.
build and boot tested.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Turn several drivers/serial/ semaphores-used-as-mutex into mutexes
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Jim Alexander reported a problem where "if one calls open() in
blocking mode with CLOCAL off, the 8250.c driver under the 2.6
kernel (or at least 2.6.8 and 2.6.10) does not wake up the
blocked process when DCD is asserted."
Fix this by enabling modem status interrupts immediately before
we read the carrier detect status.
Thanks to Jim for reporting the problem and testing the fix.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The function uart_match_port() incorrectly compares the ioremap'd
virtual addresses of ports instead of the physical address to find
duplicate ports for MMIO based UARTs. This fixes it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch marks a few serial data structures const, moving them to
.rodata where they won't false-share cachelines with things that get
written to.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If we fail to re-startup a serial port on resume, shut it down
immediately and mark it as an error condition.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The offsets of the registers are in a different place, and
some parts cannot handle a full set of modem control signals.
Signed-off-by: Pantelis Antoniou <pantelis@embeddedalley.ocm>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Folk seem to get confused when they see two or more ttyS0 ports
appearing at boot time. One comes from the legacy table, and
one from PNP.
Hence, display the bus ID of the device which supplied the port.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch fixes an issue reported by Coverity in serial/serial_core.c
Error reported: Variable "&((info)->tty)->flags" tracked as NULL was passed to a
function that dereferences it.
The later statements in the function assumes 'info->tty != NULL', so this
check is not necessary. Probably a 'BUG_ON(info->tty == NULL)' can be added.
Signed-off-by: Jayachandran C. <c.jayachandran at gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pre-format the IO part of the ttyS printks, and prefix them with
KERN_INFO to avoid bootsplash corruption.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Sascha Hauer
This patch adds support for setting and getting RTS / CTS via
set_mtctrl / get_mctrl functions.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The start_tx and stop_tx methods were passed a flag to indicate
whether the start/stop was from the tty start/stop callbacks, and
some drivers used this flag to decide whether to ask the UART to
immediately stop transmission (where the UART supports such a
feature.)
There are other cases when we wish this to occur - when CTS is
lowered, or if we change from soft to hard flow control and CTS
is inactive. In these cases, this flag was false, and we would
allow the transmitter to drain before stopping.
There is really only one case where we want to let the transmitter
drain before disabling, and that's when we run out of characters
to send.
Hence, re-jig the start_tx and stop_tx methods to eliminate this
flag, and introduce new functions for the special "disable and
allow transmitter to drain" case.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Initialise the spinlock for port being used by the console early, but
don't re-initialise it again later.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix bugme #4712: read the CTS status and set hw_stopped if CTS
is not active when opening the port and/or enabling CRTSCTS
Thanks to Stefan Wolff for spotting this problem.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch changes the way serial ports are locked when getting modem
status. This change is necessary because we will need to atomically
read the modem status and take action depending on the CTS status.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
