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!
