After overruns the FIFO pointers become misaligned. This
typically shows by characters still being stuck in the FIFO
despite the empty flag being asserted. After the first
assertion of the overrun flag the empty flag still seems to
indicate FIFO state correctly and all data can be read.
However, after another overrun assertion the FIFO seems to
be off by one such that the last received character is still
in the FIFO (despite the empty flag being asserted).

Flushing the receive FIFO reinitializes pointers. Hence it
is recommended to flush the FIFO after overruns, see also:
https://community.nxp.com/thread/321175

Hence, on assertion of the overrun flag read the remaining
data from the FIFO and flush buffers.
Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Acked-by: Max Krummenacher <max.krummenacher@toradex.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Cory Tusar <cory.tusar@zii.aero>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-imx@nxp.com
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20190729195226.8862-3-andrew.smirnov@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When using DMA framing error get cleared properly. However, due
to the additional read from the data register, an underflow in
the receive FIFO buffer occurs (the FIFO pointer gets out of
sync).

Clear the FIFO in case an underflow has occurred. Also disable the
receiver during this operation and when reading the data register to
minimize potential interference.
Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Acked-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Cory Tusar <cory.tusar@zii.aero>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-imx@nxp.com
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20190729195226.8862-2-andrew.smirnov@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Called in only one place, for RS232, it only obscures things, as it
doesn't go well with 2 similar named functions,
imx_uart_rts_inactive() and imx_uart_rts_active(), that both are
RS485-specific.
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sergey Organov <sorganov@gmail.com>
Link: https://lore.kernel.org/r/1564167161-3972-4-git-send-email-sorganov@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

imx_uart_set_mctrl() happened to set UCR2_CTSC bit whenever TIOCM_RTS
was set, no matter if RTS/CTS handshake is enabled or not. Now fixed by
turning handshake on only when CRTSCTS bit for the port is set.
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sergey Organov <sorganov@gmail.com>
Link: https://lore.kernel.org/r/1564167161-3972-3-git-send-email-sorganov@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Don't let receiver hardware automatically control RTS output if it
was requested to be inactive.

To ensure this, set_termios() shouldn't set UCR2_CTSC bit if UCR2_CTS
(=TIOCM_RTS) is cleared. Added corresponding check in imx_uart_rts_auto()
to fix this.
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Tested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Sergey Organov <sorganov@gmail.com>
Link: https://lore.kernel.org/r/1564167161-3972-2-git-send-email-sorganov@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The established way to provide PM callbacks is through struct dev_pm_ops
which is more generic.

Convert driver to use it instead of legacy approach.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190726172817.73253-1-andriy.shevchenko@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add support for NI-Serial PXIe-RS232, PXI-RS485 and PXIe-RS485 devices.
Signed-off-by: Je Yen Tam <je.yen.tam@ni.com>
Link: https://lore.kernel.org/r/20190726074012.2590-1-je.yen.tam@ni.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use __maybe_unused for power management related functionsinstead of

fixes: 270e5a74 ("serial: stm32: add wakeup mechanism")
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>

Link: https://lore.kernel.org/r/1560433800-12255-6-git-send-email-erwan.leray@st.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use pm_runtime for clock management.
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>

Link: https://lore.kernel.org/r/1560433800-12255-5-git-send-email-erwan.leray@st.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Select either pinctrl sleep state in suspend function or default state in
resume function.
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>

Link: https://lore.kernel.org/r/1560433800-12255-4-git-send-email-erwan.leray@st.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a note for enabling wakeup capabilities of usart
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>

Link: https://lore.kernel.org/r/1560433800-12255-2-git-send-email-erwan.leray@st.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

pci_ioremap_bar may return null. This is eventually de-referenced at
drivers/dma/dw/core.c:1154 and drivers/dma/dw/core.c:1168. A null check
is needed to prevent null de-reference. I am adding the check and in
case of failure. Thanks to Andy Shevchenko for the hint on the necessity
of pci_iounmap when exiting.
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20190719174848.24216-1-navid.emamdoost@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

VF610/LS1021a/i.MX7ULP/i.MX8QXP reference manual describe the
TXFIFOSIZE/RXFIFOSIZE field as below.

000b - FIFO/Buffer depth = 1 dataword.
001b - FIFO/Buffer depth = 4 datawords.
010b - FIFO/Buffer depth = 8 datawords.
011b - FIFO/Buffer depth = 16 datawords.
100b - FIFO/Buffer depth = 32 datawords.
101b - FIFO/Buffer depth = 64 datawords.
110b - FIFO/Buffer depth = 128 datawords.
111b - FIFO/Buffer depth = 256 datawords. (Reserved for VF610)

So the FIFO depth should be: 0x1 << (val ? (val + 1) : 0)
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Link: https://lore.kernel.org/r/20190717051930.15514-6-fugang.duan@nxp.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Since .sg_init_one() already set sg entry page like below code.
	sg_init_one()
		sg_init_table(sg, 1);
		sg_set_buf(sg, buf, buflen);

So it should not set sg entry page again, remove the redundant code.
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Link: https://lore.kernel.org/r/20190717051930.15514-5-fugang.duan@nxp.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use kzalloc() instead of kmalloc() to get clean rx buffer
that is useful for DMA mode debug to check the data moving
validity.
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Link: https://lore.kernel.org/r/20190717051930.15514-4-fugang.duan@nxp.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add earlycon support for imx8qxp platform.
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Link: https://lore.kernel.org/r/20190717051930.15514-3-fugang.duan@nxp.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

By default, .of_dma_configure() init dev.coherent_dma_mask to BIT(32) that
match the eDMA address range. If re-init dev.coherent_dma_mask to zero, then
streaming dma mapping will go swiotlb dma_map, if swiotlb is not initalized
then it causes mapping failed.
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Link: https://lore.kernel.org/r/20190717051930.15514-2-fugang.duan@nxp.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array.

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190721150135.82065-1-andriy.shevchenko@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Link: https://lore.kernel.org/r/20190724131825.1875-1-hslester96@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Link: https://lore.kernel.org/r/20190724131758.1764-1-hslester96@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The variable word_count is being assigned a value that is never read before
a return, the assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20190723150314.14513-1-colin.king@canonical.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

pci_alloc_consistent calls dma_alloc_coherent directly.
In commit 518a2f19
("dma-mapping: zero memory returned from dma_alloc_*"),
dma_alloc_coherent has already zeroed the memory.
So memset is not needed.
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Link: https://lore.kernel.org/r/20190715032001.7212-1-huangfq.daxian@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the typical style of array, not the equivalent &array[0].
Signed-off-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/1be432798311378947ec4e6051cad1235b6eccbb.1562283944.git.joe@perches.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

For many years omap variants have been setting the runtime PM
autosuspend delay to -1 to prevent unsafe policy with lossy first
character on wake-up. The user must specifically enable the timeout
for UARTs if desired.

We must not enable the workaround for serdev devices though. It leads
into UARTs not idling if no serdev devices are loaded and there is no
sysfs entry to configure the UART in that case. And this means that
my PM may not work unless the serdev modules are loaded.

We can detect a serdev device being configured based on a dts child
node, and we can simply skip the workround in that case. And the
serdev driver can idle the port during runtime when suitable if an
out-of-band wake-up GPIO line exists for example.

Let's also add some comments to the workaround while at it.

Cc: Johan Hovold <johan@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20190723115400.46432-1-tony@atomide.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Make it obvious how the gsm mux number relates to the virtual tty lines
by using helper functions instead of shifting 6 bits.
Signed-off-by: Martin Hundebøll <martin@geanix.com>
Link: https://lore.kernel.org/r/20190710192656.60381-3-martin@geanix.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no reason to gues the line discipline number when it is
available from tty.h
Signed-off-by: Martin Hundebøll <martin@geanix.com>
Link: https://lore.kernel.org/r/20190710192656.60381-2-martin@geanix.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The n_gsm driver handles registration of /dev/gsmttyX nodes, so there's
no need to do mknod manually.
Signed-off-by: Martin Hundebøll <martin@geanix.com>
Link: https://lore.kernel.org/r/20190710192656.60381-1-martin@geanix.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull dax fixes from Dan Williams:
 "A filesystem-dax and device-dax fix for v5.3.

  The filesystem-dax fix is tagged for stable as the implementation has
  been mistakenly throwing away all cow pages on any truncate or hole
  punch operation as part of the solution to coordinate device-dma vs
  truncate to dax pages.

  The device-dax change fixes up a regression this cycle from the
  introduction of a common 'internal per-cpu-ref' implementation.

  Summary:

   - Fix dax_layout_busy_page() to not discard private cow pages of
     fs/dax private mappings.

   - Update the memremap_pages core to properly cleanup on behalf of
     internal reference-count users like device-dax"

* tag 'dax-fixes-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  mm/memremap: Fix reuse of pgmap instances with internal references
  dax: dax_layout_busy_page() should not unmap cow pages

Pull NTB fix from Jon Mason:
 "Bug fix for NTB MSI kernel compile warning"

* tag 'ntb-5.3-bugfixes' of git://github.com/jonmason/ntb:
  NTB/msi: remove incorrect MODULE defines

Pull RISC-V updates from Paul Walmsley:
 "A few minor RISC-V updates for v5.3-rc4:

   - Remove __udivdi3() from the 32-bit Linux port, converting the only
     upstream user to use do_div(), per Linux policy

   - Convert the RISC-V standard clocksource away from per-cpu data
     structures, since only one is used by Linux, even on a multi-CPU
     system

   - A set of DT binding updates that remove an obsolete text binding in
     favor of a YAML binding, fix a bogus compatible string in the
     schema (thus fixing a "make dtbs_check" warning), and clarifies the
     future values expected in one of the RISC-V CPU properties"

* tag 'riscv/for-v5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  dt-bindings: riscv: fix the schema compatible string for the HiFive Unleashed board
  dt-bindings: riscv: remove obsolete cpus.txt
  RISC-V: Remove udivdi3
  riscv: delay: use do_div() instead of __udivdi3()
  dt-bindings: Update the riscv,isa string description
  RISC-V: Remove per cpu clocksource

Pull x86 fixes from Thomas Gleixner:
 "A few fixes for x86:

   - Don't reset the carefully adjusted build flags for the purgatory
     and remove the unwanted flags instead. The 'reset all' approach led
     to build fails under certain circumstances.

   - Unbreak CLANG build of the purgatory by avoiding the builtin
     memcpy/memset implementations.

   - Address missing prototype warnings by including the proper header

   - Fix yet more fall-through issues"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/lib/cpu: Address missing prototypes warning
  x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS
  x86/purgatory: Do not use __builtin_memcpy and __builtin_memset
  x86: mtrr: cyrix: Mark expected switch fall-through
  x86/ptrace: Mark expected switch fall-through

Pull perf tooling fixes from Thomas Gleixner:
 "Perf tooling fixes all over the place:

   - Fix the selection of the main thread COMM in db-export

   - Fix the disassemmbly display for BPF in annotate

   - Fix cpumap mask setup in perf ftrace when only one CPU is present

   - Add the missing 'cpu_clk_unhalted.core' event

   - Fix CPU 0 bindings in NUMA benchmarks

   - Fix the module size calculations for s390

   - Handle the gap between kernel end and module start on s390
     correctly

   - Build and typo fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf pmu-events: Fix missing "cpu_clk_unhalted.core" event
  perf annotate: Fix s390 gap between kernel end and module start
  perf record: Fix module size on s390
  perf tools: Fix include paths in ui directory
  perf tools: Fix a typo in a variable name in the Documentation Makefile
  perf cpumap: Fix writing to illegal memory in handling cpumap mask
  perf ftrace: Fix failure to set cpumask when only one cpu is present
  perf db-export: Fix thread__exec_comm()
  perf annotate: Fix printing of unaugmented disassembled instructions from BPF
  perf bench numa: Fix cpu0 binding

Pull scheduler fixes from Thomas Gleixner:
 "Three fixlets for the scheduler:

   - Avoid double bandwidth accounting in the push & pull code

   - Use a sane FIFO priority for the Pressure Stall Information (PSI)
     thread.

   - Avoid permission checks when setting the scheduler params for the
     PSI thread"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/psi: Do not require setsched permission from the trigger creator
  sched/psi: Reduce psimon FIFO priority
  sched/deadline: Fix double accounting of rq/running bw in push & pull

Pull irq fix from Thomas Gleixner:
 "A small fix for the affinity spreading code.

  It failed to handle situations where a single vector was requested
  either due to only one CPU being available or vector exhaustion
  causing only a single interrupt to be granted.

  The fix is to simply remove the requirement in the affinity spreading
  code for more than one interrupt being available"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/affinity: Create affinity mask for single vector

Pull objtool warning fix from Thomas Gleixner:
 "The recent objtool fixes/enhancements unearthed a unbalanced CLAC in
  the i915 driver.

  Chris asked me to pick the fix up and route it through"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  drm/i915: Remove redundant user_access_end() from __copy_from_user() error path

Pull gfs2 fix from Andreas Gruenbacher:
 "Fix incorrect lseek / fiemap results"

* tag 'gfs2-v5.3-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: gfs2_walk_metadata fix

A compilation -Wimplicit-fallthrough warning was enabled by commit
a035d552 ("Makefile: Globally enable fall-through warning")

Even though clang 10.0.0 does not currently support this warning without
a patch, clang currently does not support a value for this option.

  Link: https://bugs.llvm.org/show_bug.cgi?id=39382

The gcc default for this warning is 3 so removing the =3 has no effect
for gcc and enables the warning for patched versions of clang.

Also remove the =3 from an existing use in a parisc Makefile:
arch/parisc/math-emu/Makefile
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-and-tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull char/misc driver fixes Greg KH:
 "Here are some small char/misc driver fixes for 5.3-rc4.

  Two of these are for the habanalabs driver for issues found when
  running on a big-endian system (are they still alive?) The others are
  tiny fixes reported by people, and a MAINTAINERS update about the
  location of the fpga development tree.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  coresight: Fix DEBUG_LOCKS_WARN_ON for uninitialized attribute
  MAINTAINERS: Move linux-fpga tree to new location
  nvmem: Use the same permissions for eeprom as for nvmem
  habanalabs: fix host memory polling in BE architecture
  habanalabs: fix F/W download in BE architecture

Pull driver core fixes from Greg KH:
 "Here are two small fixes for some driver core issues that have been
  reported. There is also a kernfs "fix" here, which was then reverted
  because it was found to cause problems in linux-next.

  The driver core fixes both resolve reported issues, one with gpioint
  stuff that showed up in 5.3-rc1, and the other finally (and hopefully)
  resolves a very long standing race when removing glue directories.
  It's nice to get that issue finally resolved and the developers
  involved should be applauded for the persistence it took to get this
  patch finally accepted.

  All of these have been in linux-next for a while with no reported
  issues. Well, the one reported issue, hence the revert :)"

* tag 'driver-core-5.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Revert "kernfs: fix memleak in kernel_ops_readdir()"
  kernfs: fix memleak in kernel_ops_readdir()
  driver core: Fix use-after-free and double free on glue directory
  driver core: platform: return -ENXIO for missing GpioInt