linux.git/drivers/serial/8250.c, branch v2.6.32

serial: fix printk format specifiers for struct uart_port::iobase

2009-11-12T15:25:57+00:00

struct uart_port::iobase is unsigned long, so use %lx as printk format
specifier.

Signed-off-by: Lennert Buytenhek 
Cc: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

serial: add parameter to force skipping the test for the TXEN bug

2009-10-01T23:11:16+00:00

Allow users to force skipping the TXEN test at init time. Applies
to all serial ports. Intended for debugging only.

There is a blacklist for devices where we need to skip the test but the
list is not complete.  This lets users force skipping the test so we can
determine if they need to be added to the list.

Some HP machines with weird serial consoles have this problem and there
may be more.

Signed-off-by: Chuck Ebbert 
Cc: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

serial: move delta_msr_wait into the tty_port

2009-09-19T20:13:31+00:00

This is used by various drivers not just serial and can be extracted
as commonality

Signed-off-by: Alan Cox

serial: kill off uart_info

2009-09-19T20:13:28+00:00

We moved this into uart_state, now move the fields out of the separate
structure and kill it off.

Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

8250: Now honours baud rate lower bounds

2009-09-19T20:13:20+00:00

A platform clock drives 8250 ports in most SOC systems, the clock
might run at high frequencies, and so it's not always possible to
downscale uart clock to a desired value.

Currently the 8250 uart driver accepts not supported baud rates, and
what is worse, it is doing this silently, and then passes not accepted
values to a new termios, so userspace has no chance to catch this kind
of errors (userspace verifies that settings were accepted by reading
back and comparing the settings).

This patch fixes the issue by passing minimum baud rate to the
uart_get_baud_rate() call, the call should take care of all bounds,
so userspace should now report:

  # stty -F /dev/ttyS0 speed 300
  115200
  stty: /dev/ttyS0: unable to perform all requested operations

p.s. uart_get_baud_rate() falls back to 9600, which still might be too
     low for some 10 GHz platforms, but that's a separate issue, and
     we can wait with fixing this till we find such a platform.

Signed-off-by: Anton Vorontsov 
Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: add IRQ trigger support

2009-09-19T20:13:19+00:00

There is currently no provision for passing IRQ trigger flags for
serial IRQs with triggering requirements (such as GPIO IRQs)

This patch adds irqflags to plat_serial8250_port that can be passed
from board file to reqest_irq() of 8250 driver

Changes are backward compatible with boards passing UPF_SHARE_IRQ flag

Tested on Zoom2 board that has IRQF_TRIGGER_RISING requirement for 8250 irq

[Moved new flag to end to fix bugs in the original with the old_serial array
	-- Alan]

Signed-off-by: Vikram Pandita 
Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

serial: add support for the TI AR7 internal UART

2009-06-11T15:51:03+00:00

This patch adds support for the TI AR7 internal UART.

Signed-off-by: Florian Fainelli 
Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds

8250: Fix oops from setserial

2009-05-29T15:42:38+00:00

If you setserial a port which has never been initialised we change the type
but don't update the I/O method pointers. The same problem is true if you
change the io type of a port - but nobody ever does that so nobody noticed!

Remember the old type and when attaching if the type has changed reload the
port accessor pointers. We can't do it blindly as some 8250 drivers load custom
accessors and we must not stomp those.

Tested-by: Victor Seryodkin 
Closes-bug: #13367
Signed-off-by: Alan Cox 
Signed-off-by: Linus Torvalds

8250: fix boot hang with serial console when using with Serial Over Lan port

2009-02-21T01:57:50+00:00

Intel 8257x Ethernet boards have a feature called Serial Over Lan.

This feature works by emulating a serial port, and it is detected by
kernel as a normal 8250 port.  However, this emulation is not perfect, as
also noticed on changeset 7500b1f602aad75901774a67a687ee985d85893f.

Before this patch, the kernel were trying to check if the serial TX is
capable of work using IRQ's.

This were done with a code similar this:

        serial_outp(up, UART_IER, UART_IER_THRI);
        lsr = serial_in(up, UART_LSR);
        iir = serial_in(up, UART_IIR);
        serial_outp(up, UART_IER, 0);

        if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT)
		up->bugs |= UART_BUG_TXEN;

This works fine for other 8250 ports, but, on 8250-emulated SoL port, the
chip is a little lazy to down UART_IIR_NO_INT at UART_IIR register.

Due to that, UART_BUG_TXEN is sometimes enabled.  However, as TX IRQ keeps
working, and the TX polling is now enabled, the driver miss-interprets the
IRQ received later, hanging up the machine until a key is pressed at the
serial console.

This is the 6 version of this patch.  Previous versions were trying to
introduce a large enough delay between serial_outp and serial_in(up,
UART_IIR), but not taking forever.  However, the needed delay couldn't be
safely determined.

At the experimental tests, a delay of 1us solves most of the cases, but
still hangs sometimes.  Increasing the delay to 5us was better, but still
doesn't solve.  A very high delay of 50 ms seemed to work every time.

However, poking around with delays and pray for it to be enough doesn't
seem to be a good approach, even for a quirk.

So, instead of playing with random large arbitrary delays, let's just
disable UART_BUG_TXEN for all SoL ports.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Mauro Carvalho Chehab 
Cc: Alan Cox 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fix early_serial_setup() regression

2009-01-13T22:03:43+00:00

Commit b430428a188e8a434325e251d0704af4b88b4711 ("8250: Don't clobber
spinlocks.") introduced a regression on the parisc architecture, which
broke the handover to the serial port at boottime.

early_serial_setup() was changed to only copy a subset of the uart_port
fields, and sadly the "type" and "line" fields were forgotten and thus
the serial port was not initialized and could not be used for a
handover.  This patch fixes this by copying the missing fields.

As this change to early_serial_setup() doesn't need an initialized
spinlock in the uart_port struct any longer, we can drop the spinlock
initialization in the superio driver.

Cc: David Daney 
Cc: Tomaso Paoletti 
Cc: Andrew Morton 
Cc: Alan Cox 
Acked-by: Kyle McMartin 
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Helge Deller 
Signed-off-by: Linus Torvalds