This reverts commit f2ee6dfa0e8597eea8b98d240b0033994e20d215.

Jakub Kiciński observed that this patch can cause the pl011
driver to hang if if the only process with a pl011 port open is
killed by a signal, pl011_shutdown() can get called with an
arbitrary amount of data still in the FIFO.

Calling _shutdown() with the TX FIFO non-empty is questionable
behaviour and my itself be a bug.

Since the affected patch was speculative anyway, and brings limited
benefit, the simplest course is to remove the assumption that TXIS
will always be left asserted after the port is shut down.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There is pm_qos_add_request() being executed on serial_omap_probe(),
which stores "&up->pm_qos_request" from omap-serial driver to
"pm_qos_array[PM_QOS_CPU_DMA_LATENCY]->constraints". If
serial_omap_probe() fails after pm_qos_add_request() (e.g. on
uart_add_one_port() call), pm_qos_array still keeping pm_qos_request
struct from omap-serial driver, which is not valid anymore (since driver
failed). This leads further to kernel crash on pm_qos_update_target(),
executing from some completely different driver.

We were observing this while trying to run audio playback while having
one of omap-serial driver instances failed on uart_add_one_port() call:
    Unable to handle kernel paging request at virtual address fffffffc
    Backtrace:
    (plist_add) from (pm_qos_update_target)
    (pm_qos_update_target) from (pm_qos_add_request)
    (pm_qos_add_request) from (snd_pcm_hw_params)
    (snd_pcm_hw_params) from (snd_pcm_common_ioctl1)
    (snd_pcm_common_ioctl1) from (snd_pcm_playback_ioctl1)
    (snd_pcm_playback_ioctl1) from (snd_pcm_playback_ioctl)
    (snd_pcm_playback_ioctl) from (do_vfs_ioctl)
    (do_vfs_ioctl) from (SyS_ioctl)
    (SyS_ioctl) from (ret_fast_syscall)

This patch adds pm_qos_remove_request() on fail path in
serial_omap_probe() in order to fix this issue. While at it, free the
wakeup settings on fail path as well, just like it's done in
serial_omap_remove().

Signed-off-by: Semen Protsenko <semen.protsenko@globallogic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Log warnings meant to help diagnose problems setting up earlycon
are reporting false positives for 'console='. Revert to the
previous behavior which reported nothing.

Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Robert Schwebel <r.schwebel@pengutronix.de>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The Exar XR17V358 chip usually provides only 8 ports. But two chips can be
combined to act as a single 16 port chip. Therefor one chip is configured
as master the second as slave by connecting the mode pin to VCC (master)
or GND (slave).

Then the master chip is reporting a different device-id depending on
whether a slave is detected or not. The UARTs 8-15 are addressed from
0x2000-0x3fff. So the offset of 0x400 from UART to UART can be used to
address all 16 ports as before.

See: https://www.exar.com/common/content/document.ashx?id=1587 page 11

Signed-off-by: Soeren Grunewald <soeren.grunewald@desy.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes problems with serial console break. When function
s3c64xx_serial_startup() was started while serial console has been working,
it caused lose of characters written to TX FIFO. This effect was particularly
observable with systemd, which closes serial port every time when it's
not currently needed, hence function s3c64xx_serial_startup() is called
quite often there. To fix this problem we avoid resetting TX FIFO if port is
used as serial console.

Example of broken console log:

[ 1086.7         Expecting device dev-ttySAC1.device...
[ 1086.[  OK  ] Reached target Paths.
[ 1086.756416] s[  OK  ] Reached target Swap.
[ 1086.776413] systemd[1]: Reached target Swap.
[ 1086.776642] systemd[1]: Starting Root Slice.
[    5.53403[  OK  ] Created slice Root Slice.
[    5.548433] systemd[1]: Create[  OK  ] Created slice User and Session Slice.
[    5.568414] sys[  OK  ] Listening on /dev/initctl Compatibility Named Pipe.
[    5.588388] s[  OK  ] Listening on Delayed Shutdown Socket.
[    5.608376] sy[  OK  ] Listening on Journal Socket (/dev/log).
[    5.628361] [  OK  ] Listening on udev Kernel Socket.
[    5.648357] s[  OK  ] Listening on udev Control Socket.
[    5.668353] s[  OK  ] Listening on Journal Socket.
[    5.688366] systemd[1]: Listeni[  OK  ] Created slice System Slice.
[    5.708393]          Mounting Temporary Directory...
[ 7139.067436]          Starting prepare device daemon...
[ 7139.091726] sy         Starting Generate environment from /etc/profile.d...
[    5.792867] system         Starting Create Static Device Nodes in /dev...
[ 7848.718         Mounting Debug File System...
[ 7848.7384         Mounting Configuration File System...
[    5.852         Starting Apply Kernel Variables...
[    5.8720         Starting Setup Virtual Console...
[ 7848.798         Starting udev Coldplug all Devices...
[ 7848.817         Starting Journal Service...
[  OK  ] Started Journal Service.
[ 7848.854222] s[  OK  ] Reached target Slices.
         Starting Remount Root and Kernel File Systems...
[  OK  ] Mounted Configuration File System.

Reported-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Maxburst was not set when doing the dma slave configuration. This value
is checked by the recently introduced xdmac. It causes an error when
doing the slave configuration and so prevents from using dma.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: <stable@vger.kernel.org> # 3.12 and later
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Do not probe all serial drivers by of_serial.c which are using
device_type = "serial"; property. Only drivers which have valid
compatible strings listed in the driver should be probed.

When PORT_UNKNOWN is setup probe will fail anyway.

Arnd quotation about driver historical background:
"when I wrote that driver initially, the idea was that it would
get used as a stub to hook up all other serial drivers but after
that, the common code learned to create platform devices from DT"

This patch fix the problem with on the system with xilinx_uartps and
16550a where of_serial failed to register for xilinx_uartps and because
of irq_dispose_mapping() removed irq_desc. Then when xilinx_uartps was asking
for irq with request_irq() EINVAL is returned.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
CC: <stable@vger.kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

For systems with CONFIG_SERIAL_OF_PLATFORM=y and device_type =
"serial"; property in DT of_serial.c driver maps and unmaps IRQ (because
driver probe fails). Then a driver is called but irq mapping is not
created that's why driver is failing again in again on request_irq().
Based on this use platform_get_irq() instead of platform_get_resource()
which is doing irq_desc allocation and driver itself can request IRQ.

Fix both xilinx serial drivers in the tree.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix uart_console_write() kernel-doc build warnings.

Warning(drivers/tty/serial/serial_core.c:1778): No description found for parameter 'putchar'
Warning(drivers/tty/serial/serial_core.c:1778): Excess function parameter 'write' description in 'uart_console_write'

Fixes: 1cfe42b7fd29 ("serial: core: Fix kernel doc for uart_console_write()")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull second batch of devicetree updates from Rob Herring:
 "As Grant mentioned in the first devicetree pull request, here is the
  2nd batch of DT changes for 4.1.  The main remaining item here is the
  endianness bindings and related 8250 driver support.

   - DT endianness specification bindings

   - big-endian 8250 serial support

   - DT overlay unittest updates

   - various DT doc updates

   - compile fixes for OF_IRQ=n"

* tag 'devicetree-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  frv: add io{read,write}{16,32}be functions
  mn10300: add io{read,write}{16,32}be functions
  Documentation: DT bindings: add doc for Altera's SoCFPGA platform
  of: base: improve of_get_next_child() kernel-doc
  Doc: dt: arch_timer: discourage clock-frequency use
  of: unittest: overlay: Keep track of created overlays
  of/fdt: fix allocation size for device node path
  serial: of_serial: Support big-endian register accesses
  serial: 8250: Add support for big-endian MMIO accesses
  of: Document {little,big,native}-endian bindings
  of/fdt: Add endianness helper function for early init code
  of: Add helper function to check MMIO register endianness
  of/fdt: Remove "reg" data prints from early_init_dt_scan_memory
  of: add vendor prefix for Artesyn
  of: Add dummy of_irq_to_resource_table() for IRQ_OF=n
  of: OF_IRQ should depend on IRQ_DOMAIN