The size of the DMA buffer can affect the delta time between data being
produced and data being consumed. Basically the DMA system will move
data to tty buffer when a) DMA buffer is full b) serial line is idle.
The situation is visible when producer generates data continuously and
there is no possibility for idle line. At this point the DMA buffer is
directly affecting the delta time.

The patch will add the possibility to configure the DMA buffers in DT,
which case by case can be configured separately for every driver
instance. The DT configuration is optional and in case missing the
driver will use the 4096 buffer with 4 periods (as before), therefore no
clients are impacted by this change.
Signed-off-by: Nandor Han <nandor.han@ge.com>
Signed-off-by: Romain Perier <romain.perier@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently, this IRQ is always enabled. Some devices might mux these pins
to other I/Os, like I2C. This could lead to spurious interrupts.

This commit makes this IRQ optional, by using the field have_rtscts.
Signed-off-by: Nandor Han <nandor.han@ge.com>
Signed-off-by: Romain Perier <romain.perier@collabora.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

IRDA support is gone since commit afe9cbb1 ("serial: imx: drop
support for IRDA"), so remove the remaining irda members from
imx_port structure.

While at it, also remove 'trcv_delay' which is also unused.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

DMA RX completion handler for UART is called from a tasklet and hence
may be delayed depending on the system load. In meanwhile, there may be
RX timeout interrupt which can get serviced first before DMA RX
completion handler is executed for the completed transfer.
omap_8250_rx_dma_flush() which is called on RX timeout interrupt makes
sure that the DMA RX buffer is pushed and then the FIFO is drained and
also queues a new DMA request. But, when DMA RX completion handler
executes, it will erroneously flush the currently queued DMA transfer
which sometimes results in data corruption and double queueing of DMA RX
requests.

Fix this by checking whether RX completion is for the currently queued
transfer or not. And also hold port lock when in DMA completion to avoid
race wrt RX timeout handler preempting it.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The BCM2835 MINI UART has non-standard THRE semantics. Conventionally
the bit means that the FIFO is empty (although there may still be a
byte in the transmit register), but on 2835 it indicates that the FIFO
is not full. This causes interrupts after every byte is transmitted,
with the FIFO providing some interrupt latency tolerance.

A consequence of this difference is that the usual strategy of writing
multiple bytes into the TX FIFO after checking THRE once is unsafe.
In the worst case of 7 bytes in the FIFO, writing 8 bytes loses all
but the first since by then the FIFO is full.

There is an HFIFO ("Hidden FIFO") capability that causes the transmit
loop to terminate when both THRE and TEMT are set, i.e. when the TX
block is completely idle. This is unnecessarily cautious, potentially
causing gaps in transmission.

Add a new conditional to the transmit loop, predicated on CAP_MINI,
that exits when THRE is no longer set (the FIFO is full). This allows
the FIFO to fill quickly but subsequent writes are paced by the
transmission rate.
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Acked-by: Eric Anholt <eric@anholt.net>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch handle the stable UART bindings but also keeps compatibility
with the legacy non-stable bindings until all boards uses them.
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Helmut Klein <hgkr.klein@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the documentation for the device tree binding of Amlogic Meson Serial UART.
Signed-off-by: Helmut Klein <hgkr.klein@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit e4fda3a0 ("serial: don't register CIR serial ports") adds a
check for PORT_8250_CIR to serial8250_register_8250_port(). But the code
isn't needed as the function never takes the branch when the port is CIR
serial port.

This patch deletes the dead code.
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

of_device_ids are not supposed to change at runtime. All functions
working with of_device_ids provided by <linux/of.h> work with const
of_device_ids. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use dma_alloc_attrs directly instead of the dma_alloc_noncoherent wrapper.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This implements an earlycon for Actions Semi S500/S900 SoCs.

Based on LeMaker linux-actions tree.
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This UART is found on S500 and S900 SoCs.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that AVR32 is gone, platform_data are not used to initialize the driver
anymore, remove that path from the driver. Also remove the now unused
struct atmel_uart_data.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

atmel_default_console_device was only used by AVR32, in particular
arch/avr32/mach-at32ap/at32ap700x.c which is now gone. Remove it from the
driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Drop the now unused alt_speed field from struct tty_struct.

Setting an alt_speed using the ASYNC_SPD flags has been deprecated since
v2.1.69, and has been broken for all tty drivers but serial-core since
v3.10 and commit 6865ff22 ("TTY: do not warn about setting speed via
SPD_*") without anyone noticing.

Note that serial-core still supports changing speed using TIOCSSERIAL
and SPD flags (including "alt-speeds"), but also warns about it being
deprecated since pre-git.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove three ifdefed and broken implementations of TIOCSSERIAL and
TIOCGICOUNT, and parity handling in set_termios which had suffered
severe bit rot.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Setting an alt_speed using the ROCKET_SPD flags has been deprecated
since v2.1.69, and has been broken since commit 6865ff22 ("TTY: do
not warn about setting speed via SPD_*") without anyone noticing.

To make things worse commit 6df3526b ("rocket: first pass at termios
reporting") in v2.6.25 started reporting back the actual baud rate used,
something which also required 38400 to again be set whenever changing a
SPD flag.

Drop the broken alt-speed handling altogether, and add a ratelimited
warning about using TIOCCSERIAL to change speed as being deprecated.

Note that the rocket driver has never supported using a custom divisor
(ASYNC_SPD_CUST equivalent).
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Setting an alt_speed using the ASYNC_SPD flags has been deprecated since
v2.1.69, and has been broken since v3.10 and commit 6865ff22 ("TTY:
do not warn about setting speed via SPD_*") without anyone noticing.

Drop the broken alt-speed handling altogether, and add a ratelimited
warning about using TIOCCSERIAL to to change speed as being deprecated.

Note that using ASYNC_SPD_CUST is still supported.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Setting an alt_speed using the ASYNC_SPD flags has been deprecated since
v2.1.69, and has been broken since v3.10 and commit 6865ff22 ("TTY:
do not warn about setting speed via SPD_*") without anyone noticing.

Drop the broken alt-speed handling altogether, and add a ratelimited
warning about using TIOCCSERIAL to change speed as being deprecated.

Note that using ASYNC_SPD_CUST is still supported.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This driver was setting the deprecated and broken alt_speed based on port
flags, but never provided a means to change the flags or to actually
change the speed.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove the broken alt_speed code, and warn when trying to set the line
speed using TIOCSSERIAL and SPD flags.

The use of SPD flags to set the line speed has been deprecated since
v2.1.69 and support for alt_speed (e.g. "warp") has even been removed
from TTY core in v3.10 by commit 6865ff22 ("TTY: do not warn about
setting speed via SPD_*"), effectively breaking all driver
implementations of this except for serial core.

Also remove the verbose and outdated comment on how to set baud rates.

Note that setting a custom divisor will continue to work with the
caveat that 38400 must again be selected every time the divisor is
changed since v2.6.24 and commit 669a6db1 ("USB: ftd_sio: cleanups
and updates for new termios work") which started reporting back the
actual baud rate used.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Simplify TIOCSSERIAL flag logic somewhat.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Contrary to what a comment claimed, the ASYNC_SPD flags and custom
divisor can be set by a non-privileged user so rate limit the
deprecation notice as was intended.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When opening the slave end of a PTY, it is not possible for userspace to
safely ensure that /dev/pts/$num is actually a slave (in cases where the
mount namespace in which devpts was mounted is controlled by an
untrusted process). In addition, there are several unresolvable
race conditions if userspace were to attempt to detect attacks through
stat(2) and other similar methods [in addition it is not clear how
userspace could detect attacks involving FUSE].

Resolve this by providing an interface for userpace to safely open the
"peer" end of a PTY file descriptor by using the dentry cached by
devpts. Since it is not possible to have an open master PTY without
having its slave exposed in /dev/pts this interface is safe. This
interface currently does not provide a way to get the master pty (since
it is not clear whether such an interface is safe or even useful).

Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Valentin Rothberg <vrothberg@suse.com>
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In order to avoid future diversions between fs/compat_ioctl.c and
drivers/tty/pty.c, define .compat_ioctl callbacks for the relevant
tty_operations structs. Since both pty_unix98_ioctl() and
pty_bsd_ioctl() are compatible between 32-bit and 64-bit userspace no
special translation is required.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Commtech adapters apparently need the original setting as outputs, see
https://marc.info/?l=linux-gpio&m=149557425201323&w=2. Account for that.

Fixes: 7dea8165 ("serial: exar: Preconfigure xr17v35x MPIOs as output")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

AVR32 is gone. Now it's time to clean up the driver by removing
leftovers that was used by AVR32 related code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Only vgacon and sisusbcon did it right, the rest (via generic code) tried
underline (usually cyan).
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The vt copy_from/to_user cleanups were in a separate branch for others
to work off of.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Done by copy_{from,to}_user().
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Again, a nice linear transfer that simplifies the code.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

A nice big linear transfer, no need to flip stac/PAN/etc every half-entry.
Also, yay __put_user() after checking only read.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Only read access is checked before this call.

Actually, at the moment this is not an issue, as every in-tree arch does
the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU
to tell them apart, but this wasn't the case in the past and may happen
again on some odd arch in the future.

If anyone cares about 3.7 and earlier, this is a security hole (untested)
on real 80386 CPUs.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
CC: stable@vger.kernel.org # v3.7-
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Linus wants to get rid of these functions, and these uses are especially
egregious: they copy a big linear array element by element.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We want the tty locking fix in here, so that maybe we can finally get it
fixed for real...
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This fixes a problem with reading files larger than 2GB from a UFS-2
file system:

    https://bugzilla.kernel.org/show_bug.cgi?id=195721

The incorrect UFS s_maxsize limit became a problem as of commit
c2a9737f ("vfs,mm: fix a dead loop in truncate_inode_pages_range()")
which started using s_maxbytes to avoid a page index overflow in
do_generic_file_read().

That caused files to be truncated on UFS-2 file systems because the
default maximum file size is 2GB (MAX_NON_LFS) and UFS didn't update it.

Here I simply increase the default to a common value used by other file
systems.
Signed-off-by: Richard Narron <comet.berkeley@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Will B <will.brokenbourgh2877@gmail.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: <stable@vger.kernel.org> # v4.9 and backports of c2a9737fSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull NFS client bugfixes from Trond Myklebust:
 "Bugfixes include:

   - Fix a typo in commit e0926934 ("NFS append COMMIT after
     synchronous COPY") that breaks copy offload

   - Fix the connect error propagation in xs_tcp_setup_socket()

   - Fix a lock leak in nfs40_walk_client_list

   - Verify that pNFS requests lie within the offset range of the layout
     segment"

* tag 'nfs-for-4.12-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  nfs: Mark unnecessarily extern functions as static
  SUNRPC: ensure correct error is reported by xs_tcp_setup_socket()
  NFSv4.0: Fix a lock leak in nfs40_walk_client_list
  pnfs: Fix the check for requests in range of layout segment
  xprtrdma: Delete an error message for a failed memory allocation in xprt_rdma_bc_setup()
  pNFS/flexfiles: missing error code in ff_layout_alloc_lseg()
  NFS fix COMMIT after COPY

Pull tty fix from Greg KH:
 "Here is a single tty core fix for 4.12-rc4. It reverts a patch that a
  lot of people reported as causing lockdep and other warnings.

  Right after I reverted this in my tree, it seems like another
  "correct" fix might have shown up, but it's too late in the release
  cycle to be messing with tty core locking, so let's just revert this
  for now to go back how things always have been and try it again for
  4.13.

  This has not been in linux-next as I only reverted it a few hours ago"

* tag 'tty-4.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "tty: fix port buffer locking"

Pull input subsystem fixes from Dmitry Torokhov:

 - a couple of regression fixes in synaptics and axp20x-pek drivers

 - try to ease transition from PS/2 to RMI for Synaptics touchpad users
   by ensuring we do not try to activate RMI mode when RMI SMBus support
   is not enabled, and nag users a bit to enable it

 - plus a couple of other changes that seemed worthwhile for this
   release

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: axp20x-pek - switch to acpi_dev_present and check for ACPI0011 too
  Input: axp20x-pek - only check for "INTCFD9" ACPI device on Cherry Trail
  Input: tm2-touchkey - use LEN_ON as boolean value instead of LED_FULL
  Input: synaptics - tell users to report when they should be using rmi-smbus
  Input: synaptics - warn the users when there is a better mode
  Input: synaptics - keep PS/2 around when RMI4_SMB is not enabled
  Input: synaptics - clear device info before filling in
  Input: silead - disable interrupt during suspend