Reported by coccinelle:

drivers/tty/serial/pch_uart.c:979:1-14: alloc with no test, possible model on line 994

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Parity Setting value is reverse.
E.G. In case of setting ODD parity, EVEN value is set.
This patch inverts "if" condition.

Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Rx Error interrupt(E.G. parity error) is not enabled.
So, when parity error occurs, error interrupt is not occurred.
As a result, the received data is not dropped.

This patch adds enable/disable rx error interrupt code.

Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Otherwise we fall back to the wrong value.

Reported-by: <dcb314@hotmail.com>
Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=44091
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

pch_uart_interrupt() takes priv->port.lock which leads to two recursive
spinlock calls if low_latency==1 or CONFIG_PREEMPT_RT_FULL=y (one
otherwise):

pch_uart_interrupt
  spin_lock_irqsave(priv->port.lock, flags)
  case PCH_UART_IID_RDR_TO (data ready)
  handle_rx_to
    push_rx
      tty_port_tty_get
        spin_lock_irqsave(&port->lock, flags) <--- already hold this lock
        ...
      tty_flip_buffer_push
        ...
        flush_to_ldisc
          spin_lock_irqsave(&tty->buf.lock)
            spin_lock_irqsave(&tty->buf.lock)
            disc->ops->receive_buf(tty, char_buf)
              n_tty_receive_buf
                tty->ops->flush_chars()
                uart_flush_chars
                  uart_start
                    spin_lock_irqsave(&port->lock) <--- already hold this lock

Avoid this by using a dedicated lock to protect the eg20t_port structure
and IO access to its membase. This is more consistent with the 8250
driver.  Ensure priv->lock is always take prior to priv->port.lock when
taken at the same time.

V2: Remove inadvertent whitespace change.
V3: Account for oops_in_progress for the private lock in
    pch_console_write().

Note: Like the 8250 driver, if a printk is introduced anywhere inside
      the pch_console_write() critical section, the kernel will hang
      on a recursive spinlock on the private lock. The oops case is
      handled by using a trylock in the oops_in_progress case.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
CC: Tomoya MORINAGA <tomoya.rohm@gmail.com>
CC: Feng Tang <feng.tang@intel.com>
CC: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This resolves the merge problem with:
	drivers/tty/serial/pch_uart.c

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This allows us to pick up some changes needed for other serial patches.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This driver anticipates pch_uart_verify_port() is not called
during installation.
However, actually pch_uart_verify_port() is called during
installation.
As a result, memory access violation occurs like below.

0. initial value: use_dma=0
1. starup()
    - dma channel is not allocated because use_dma=0
2. pch_uart_verify_port()
    - Set use_dma=1
3. UART processing acts DMA mode because use_dma=1
     - memory access violation occurs!

This patch fixes the issue.

Solution:
Whenever pch_uart_verify_port() is called and then
dma channel is not allocated, the channel should be allocated.

Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull tty and serial fixes from Greg KH:
 "Here are some tty and serial fixes for 3.4-rc2.

  Most important here is the pl011 fix, which has been reported by about
  100 different people, which means more people use it than I expected
  :)

  There are also some 8250 driver reverts due to some problems reported
  by them.  And other minor fixes as well.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'tty-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  pch_uart: Add Kontron COMe-mTT10 uart clock quirk
  pch_uart: Fix MSI setting issue
  serial/8250_pci: add a "force background timer" flag and use it for the "kt" serial port
  Revert "serial/8250_pci: setup-quirk workaround for the kt serial controller"
  Revert "serial/8250_pci: init-quirk msi support for kt serial controller"
  tty/serial/omap: console can only be built-in
  serial: samsung: fix omission initialize ulcon in reset port fn()
  printk(): add KERN_CONT where needed in hpet and vt code
  tty/serial: atmel_serial: fix RS485 half-duplex problem
  tty: serial: altera_uart: Check for NULL platform_data in probe.
  isdn/gigaset: use gig_dbg() for debugging output
  omap-serial: Fix the error handling in the omap_serial probe
  serial: PL011: move interrupt clearing

Add initialize variable to prevent duplicate free memory.

Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>