This removes duplicated initialization of variables (after reordering
'c' initialization).

It will also allow for eliminating whole translation into a separate
function in the next patch.

Note that vc_state, vc_utf etc. are checked with every rescan now. But
they are immutable for non-control characters where rescan might be
only necessary.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-15-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We continue cleaning up do_con_write. This (hopefully) makes the
inversion code obvious.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-14-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The code was too overcomplicated. Extract vc_sanitize_unicode to a
separate function and flatten the code. I believe the code is
straightforward now.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-13-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

do_con_write is complicated enough. Extract unicode handling to a
separate function. For do_con_write, 249 LOCs lowered to 183 lines.

Use diff -w -b to see the difference is neligible -- mostly whitespace
and use of 'return's instead of 'continue's.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-12-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use bools for rescan and inverse. And true/false accordingly.

Use u8 for width instead of uint8_t.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-11-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

vc_translate is used only in vt.c, so move the definition from a header
there. Also, it used to be a macro, so be modern and make a static
inline from it. This makes the code actually readable.

And as a preparation for next patches, rename it to vc_translate_ascii.
vc_translate will be a wrapper for both unicode and this one.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-10-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

VT100ID is unused, but defined twice. Kill it.

VT102ID is used only in respond_ID. Define there a variable with proper
type and use that instead. Then drop both defines of VT102ID too.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-9-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Pass the length of a string to respond_string and use
tty_insert_flip_string instead of a loop with tty_insert_flip_char. This
simplifies the processing on the tty side.

The added strlens are optimized during constant folding and propagation
and the result are proper constants in assembly.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-8-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

vc_tab_stop is used as a bitmap, but defined as an unsigned int array.
Switch it to bitmap and convert all users to the bitmap interface.

Note the difference in behavior! We no longer mask the top 24 bits away
from x, hence we do not wrap tabs at 256th column. Instead, we silently
drop attempts to set a tab behind 256 columns. And we will also seek by
'\t' to the rightmost column, when behind that boundary. I do not think
the original behavior was desired and that someone relies on that. If
this turns out to be the case, we can change the added 'if's back to
masks here and there instead...

(Or we can increase the limit as fb consoles now have 240 chars here.
And they could have more with higher than my resolution, of course.)
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-6-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Declare Gx_charset[2] instead of G0_charset and G1_charset. It makes
the code simpler (without ternary operators).
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-5-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The code for setting G0 and G1 is duplicated -- for each of them. Move
the code to a separate function (vc_setGx) and distinguish the two cases
by a parameter.

Change if-else-if to switch which allows for slightly better
optimization (decision tree).
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-4-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The code currently uses bitfields to store true-false values. Switch all
of that to bools. Apart from the cleanup, it saves 20B of code as many
shifts, ANDs, and ORs became simple movzb's.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-3-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Introduce names (en enum) for 0, 1, and 2 constants. We now have
VCI_HALF_BRIGHT, VCI_NORMAL, and VCI_BOLD instead.

Apart from the cleanup,
1) the enum allows for better type checking, and
2) this saves some code. No more fiddling with bits is needed in
   assembly now. (OTOH, the structure is larger.)
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-2-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There are two copies of some members of struct vc_data. This is because
we need to save them and restore later. Move these memebers to a
separate structure called vc_state. So now instead of members like:
  vc_x, vc_y and vc_saved_x, vc_saved_y
we have
  state and saved_state (of type: struct vc_state)
containing
  state.x, state.y and saved_state.x, saved_state.y

This change:
* makes clear what is saved & restored
* eases save & restore by using memcpy (see save_cur and restore_cur)

Finally, we document the newly added struct vc_state using kernel-doc.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-1-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit 84af7a61 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Convert comments that reference mmap_sem to reference mmap_lock instead.

[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]
Signed-off-by: NMichel Lespinasse <walken@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NDaniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now the last users of show_stack() got converted to use an explicit log
level, show_stack_loglvl() can drop it's redundant suffix and become once
again well known show_stack().
Signed-off-by: NDmitry Safonov <dima@arista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Show the stack trace on a CPU with the same log level as "CPU%d" header.
Signed-off-by: NDmitry Safonov <dima@arista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Link: http://lkml.kernel.org/r/20200418201944.482088-45-dima@arista.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implement the read() function in the early console driver. With
recently added kgdboc_earlycon feature, this allows you to use kgdb
to debug fairly early into the system boot.

We only bother implementing this if polling is enabled since kgdb can't
be enabled without that.
Signed-off-by: NSumit Garg <sumit.garg@linaro.org>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200507130644.v4.12.I8ee0811f0e0816dd8bfe7f2f5540b3dba074fae8@changeidSigned-off-by: NDaniel Thompson <daniel.thompson@linaro.org>

Implement the read() function in the early console driver.  With
recent kgdb patches this allows you to use kgdb to debug fairly early
into the system boot.

We only bother implementing this if polling is enabled since kgdb
can't be enabled without that.
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NDaniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20200507130644.v4.11.I8f668556c244776523320a95b09373a86eda11b7@changeidSigned-off-by: NDaniel Thompson <daniel.thompson@linaro.org>

Implement the read() function in the early console driver.  With
recent kgdb patches this allows you to use kgdb to debug fairly early
into the system boot.

We only bother implementing this if polling is enabled since kgdb
can't be enabled without that.
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20200507130644.v4.10.If2deff9679a62c1ce1b8f2558a8635dc837adf8c@changeidSigned-off-by: NDaniel Thompson <daniel.thompson@linaro.org>

Currently there is no guarantee that an earlycon will be initialized
before kgdboc tries to adopt it. Almost the opposite: on systems
with ACPI then if earlycon has no arguments then it is guaranteed that
earlycon will not be initialized.

This patch mitigates the problem by giving kgdboc_earlycon a second
chance during console_init(). This isn't quite as good as stopping during
early parameter parsing but it is still early in the kernel boot.
Signed-off-by: NDaniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20200430161741.1832050-1-daniel.thompson@linaro.orgReviewed-by: NDouglas Anderson <dianders@chromium.org>

When kgdboc is compiled as a module all of the "ekgdboc" and
"kgdb_earlycon" code isn't useful and, in fact, breaks compilation.
This is because early_param() isn't defined for modules and that's how
this code gets configured.

It turns out that this was broken by commit eae3e19c ("kgdboc:
Remove useless #ifdef CONFIG_KGDB_SERIAL_CONSOLE in kgdboc") and then
made worse by commit 22099562 ("kgdboc: Add kgdboc_earlycon to
support early kgdb using boot consoles").  I guess the #ifdef wasn't
so useless, even if it wasn't obvious why it was useful.  When kgdboc
was compiled as a module only "CONFIG_KGDB_SERIAL_CONSOLE_MODULE" was
defined, not "CONFIG_KGDB_SERIAL_CONSOLE".  That meant that the old
module.

Let's basically do the same thing that the old code (pre-removal of
the #ifdef) did but use "IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE)" to
make it more obvious what the point of the check is.  We'll fix
kgdboc_earlycon in a similar way.

Fixes: 22099562 ("kgdboc: Add kgdboc_earlycon to support early kgdb using boot consoles")
Fixes: eae3e19c ("kgdboc: Remove useless #ifdef CONFIG_KGDB_SERIAL_CONSOLE in kgdboc")
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200519084345.1.I91670accc8a5ddabab227eb63bb4ad3e2e9d2b58@changeidSigned-off-by: NDaniel Thompson <daniel.thompson@linaro.org>

only copy_to_user() is done to the address in question
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

To support BT use case over UART at baud rate of 3.2 Mbps,
we need SE clocks to run at 51.2MHz frequency. Previously this
frequency was not available in clk src, so, we were requesting
for 102.4 MHz and dividing it internally by 2 to get 51.2MHz.

As now 51.2MHz frequency is made available in clk src,
adding this frequency to UART frequency table.

We will save significant amount of power, if 51.2 is used
because it belongs to LowSVS range whereas 102.4 fall into
Nominal category.
Signed-off-by: Nsatya priya <skakit@codeaurora.org>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/1590747282-5487-1-git-send-email-skakit@codeaurora.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The AGTIM flag must be cleared explicitly, otherwise the IRQ handler
will be called in an endless loop.

Fortunately, this issue currently doesn't affect mainline kernels in
practice, as the the RX FIFO trigger level is set to 1 in UFCR. When
setting the trigger level to a higher number, the issue is trivially
reproducible by any RX without DMA that doesn't fill the FIFO up to the
configured level.
Signed-off-by: NMatthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20200528154747.14201-1-matthias.schiffer@ew.tq-group.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fintek F81966 is a LPC/eSPI to 6 UARTs SuperIO. It has fully compatible
with F81866. It's also need check the IRQ mode with system assigned.

F81966 IRQ Mode setting:
        0xf0
                Bit1: IRQ_MODE0
                Bit0: Share mode (always on)
        0xf6
                Bit3: IRQ_MODE1

        Level/Low: IRQ_MODE0:0, IRQ_MODE1:0
        Edge/High: IRQ_MODE0:1, IRQ_MODE1:0
Signed-off-by: NJi-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Cc: Ji-Ze Hong (Peter Hong) <peter_hong@fintek.com.tw>
Link: https://lore.kernel.org/r/20200528022429.32078-1-hpeter+linux_kernel@gmail.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This series of uart controllers is able to work in IrDA mode.
Add per-port flag to the device-tree to enable that feature if needed.
Signed-off-by: NPascal Huerst <pascal.huerst@gmail.com>
Signed-off-by: NDaniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200529055058.1606910-3-daniel@zonque.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit e8759ad1 ("serial: uapi: Add support for bus termination")
introduced the ability to enable rs485 bus termination from user space.
So far the feature is only used by a single driver, 8250_exar.c, using a
hardcoded GPIO pin specific to Siemens IOT2040 products.

Provide for a more generic solution by allowing specification of an
rs485 bus termination GPIO pin in the device tree:  Amend the serial
core to retrieve the GPIO from the device tree (or ACPI table) and amend
the default ->rs485_config() callback for 8250 drivers to change the
GPIO on request from user space.

Perhaps 8250_exar.c can be converted to the generic approach in a
follow-up patch.
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Link: https://lore.kernel.org/r/94c6c800d1ca9fa04766dd1d43a8272c5ad4bedd.1589811297.git.lukas@wunner.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The parameter is named p while the documentation talks about up.
Fix the doc to be in line with the code.

Fixes: 058bc104 ("serial: 8250: Generalize rs485 software emulation")
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NHeiko Stuebner <heiko.stuebner@theobroma-systems.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200517215610.2131618-2-heiko@sntech.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When k_ascii is invoked several times in a row there is a potential for
signed integer overflow:

UBSAN: Undefined behaviour in drivers/tty/vt/keyboard.c:888:19 signed integer overflow:
10 * 1111111111 cannot be represented in type 'int'
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.11 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xce/0x128 lib/dump_stack.c:118
 ubsan_epilogue+0xe/0x30 lib/ubsan.c:154
 handle_overflow+0xdc/0xf0 lib/ubsan.c:184
 __ubsan_handle_mul_overflow+0x2a/0x40 lib/ubsan.c:205
 k_ascii+0xbf/0xd0 drivers/tty/vt/keyboard.c:888
 kbd_keycode drivers/tty/vt/keyboard.c:1477 [inline]
 kbd_event+0x888/0x3be0 drivers/tty/vt/keyboard.c:1495

While it can be worked around by using check_mul_overflow()/
check_add_overflow(), it is better to introduce a separate flag to
signal that number pad is being used to compose a symbol, and
change type of the accumulator from signed to unsigned, thus
avoiding undefined behavior when it overflows.
Reported-by: NKyungtae Kim <kt0755@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200525232740.GA262061@dtor-wsSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some embedded devices still use these serial ports; make sure they're
still enabled by default on architectures more likely to have them, to
avoid rendering someone's console unavailable.
Reported-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reported-by: NMaxim Kochetkov <fido_max@inbox.ru>
Fixes: dc56ecb8 ("serial: 8250: Support disabling mdelay-filled probes of 16550A variants")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Link: https://lore.kernel.org/r/a20b5fb7dd295cfb48160eecf4bdebd76332d67d.1590509426.git.josh@joshtriplett.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

hvc_open sets tty->driver_data to NULL when open fails at some point.
Typically, the failure happens in hp->ops->notifier_add(). If there is
a racing process which tries to open such mangled tty, which was not
closed yet, the process will crash in hvc_open as tty->driver_data is
NULL.

All this happens because close wants to know whether open failed or not.
But ->open should not NULL this and other tty fields for ->close to be
happy. ->open should call tty_port_set_initialized(true) and close
should check by tty_port_initialized() instead. So do this properly in
this driver.

So this patch removes these from ->open:
* tty_port_tty_set(&hp->port, NULL). This happens on last close.
* tty->driver_data = NULL. Dtto.
* tty_port_put(&hp->port). This happens in shutdown and until now, this
  must have been causing a reference underflow, if I am not missing
  something.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: stable <stable@vger.kernel.org>
Reported-and-tested-by: NRaghavendra <rananta@codeaurora.org>
Link: https://lore.kernel.org/r/20200526145632.13879-1-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The commit a3cb39d2
("serial: core: Allow detach and attach serial device for console")
changed a bit logic behind lock initialization since for most of the console
driver it's supposed to have lock already initialized even if console is not
enabled. However, it's not the case for Freescale IMX console.

Initialize lock explicitly in the ->probe().

Note, there is still an open question should or shouldn't not this driver
register console properly.

Fixes: a3cb39d2 ("serial: core: Allow detach and attach serial device for console")
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200525105952.13744-1-andriy.shevchenko@linux.intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently, the driver probes just fine and binds all its resources even
if the physical device is not present.

As the device lacks an identification register, let's at least read the
LSR register to check whether a device at the configured address responds
to the request at all.
Signed-off-by: NDaniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200521091152.404404-7-daniel@zonque.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When the interrupt line is shared with other devices, the IRQ must be
level-triggered, as only one device can trigger a falling edge. To support
this, try to acquire the IRQ with IRQF_TRIGGER_LOW|IRQF_SHARED first.

Interrupt controllers that lack support for level-triggers will return an
error, in which case the driver will now retry the acqusition with
IRQF_TRIGGER_FALLING, which was also the default before.
Signed-off-by: NDaniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200521091152.404404-6-daniel@zonque.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use a threaded IRQ handler to get rid of the irq_work kthread.
This also allows for the driver to use interrupts generated by
a threaded controller.
Signed-off-by: NDaniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200521091152.404404-5-daniel@zonque.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver currently only uses IRQF_TRIGGER_FALLING if the probing
happened without a device-tree setup. The device however will always
generate falling edges on its IRQ line, so let's use that flag in
all cases.
Signed-off-by: NDaniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20200521091152.404404-4-daniel@zonque.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When submitting the previous fix "tty: n_gsm: Fix waking up upper tty
layer when room available". It was suggested to switch from a while to
a for loop, but when doing it, there was a remaining bogus i++.

This patch removes this i++ and also reorganizes the code making it more
compact.

Fixes: e1eaea46 ("tty: n_gsm line discipline")
Signed-off-by: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20200518084517.2173242-3-gregory.clement@bootlin.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the length is zero then the print_hex_dump_bytes won't output
anything, so testing the length before the call is unnecessary.
Signed-off-by: NGregory CLEMENT <gregory.clement@bootlin.com>
Link: https://lore.kernel.org/r/20200518084517.2173242-2-gregory.clement@bootlin.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>