Now that gpiolib can track the validity of GPIO pins, there is no need
to check whether the line is valid in request().
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201204164739.781812-5-maz@kernel.orgReviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
[johan: amend commit message]
Signed-off-by: NJohan Hovold <johan@kernel.org>

Since it is pretty common for only some of the CBUS lines to be
valid as GPIO lines, let's report such validity to the rest of
the kernel.
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201204164739.781812-3-maz@kernel.orgReviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add an interface-number sanity check before testing the device flags to
avoid relying on undefined behaviour when left shifting in case a device
uses an interface number greater than or equal to BITS_PER_LONG (i.e. 64
or 32).

Reported-by: syzbot+8881b478dad0a7971f79@syzkaller.appspotmail.com
Fixes: c3a65808 ("USB: serial: option: reimplement interface masking")
Cc: stable@vger.kernel.org
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Clean up dtr_rts() by renaming the port parameter and adding missing
whitespace.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add a helper function to be used to configure flow control.

The flow-control code was the last caller that relied on the
memset-on-failure behaviour of cp210x_read_reg_block(), which we can now
drop in favour of bailing out on errors when retrieving the flow-control
settings.

This should also simplify adding support for software flow control.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Drop some unnecessary flow-control debugging.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Unlike other drivers cp210x have been retrieving the current terminal
settings from the device on open and reflecting those in termios.

Due to how set_termios() used to be implemented, this saved a few
control requests on open but has instead caused problems like broken
flow control and has required adding workarounds for swapped
line-control in cp2108 and line-speed initialisation on cp2104.

This unusual implementation also complicates adding new features for no
good reason.

Rip out the corresponding code and the above mentioned workarounds and
instead initialise the terminal settings unconditionally on open.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Update the line-control settings in one request unconditionally instead
of setting the word-length, parity and stop-bit settings separately.

This avoids multiple requests when several settings are changed even if
this scheme could potentially also be used to detect unsupported device
settings. Since all device types but CP2101 appears to support all
settings, let's handle that one specifically and also report back the
unsupported settings properly through termios by clearing the
corresponding bits.

Also drop the related unnecessary debug printks.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Return early from set_termios() in case no relevant terminal settings
have changed.

This avoids testing each parameter in turn and specifically allows the
line-control handling to be cleaned up further.
Signed-off-by: NJohan Hovold <johan@kernel.org>

The parallel port restore operation currently defers writes
to a tasklet, if it sees a locked disconnect mutex. The
driver goes to a lot of trouble to ensure writes happen
in a non-blocking context, but things can be greatly
simplified if it's done in regular process context and
this is not a system performance critical path. As such,
instead of doing the state restore writes in softirq context,
use a workqueue and just do regular synchronous writes.

In addition to the cleanup, this also imposes less on the
overall system as tasklets have been deprecated because
of it's softirq implications, potentially blocking a higher
priority task from running.
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20201120045300.28804-1-dave@stgolabs.net
[johan: amend commit message ("softirq context")]
Signed-off-by: NJohan Hovold <johan@kernel.org>

The parallel-port restore operations is called when a driver claims the
port and is supposed to restore the provided state (e.g. saved when
releasing the port).

Fixes: b69578df ("USB: usbserial: mos7720: add support for parallel port on moschip 7715")
Cc: stable <stable@vger.kernel.org>     # 2.6.35
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The digi_acceleport driver is the only driver still using the port
write wake queue so move it to that driver's port data.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The driver must not call tty_wakeup() while holding its private lock as
line disciplines are allowed to call back into write() from
write_wakeup(), leading to a deadlock.

Also remove the unneeded work struct that was used to defer wakeup in
order to work around a possible race in ancient times (see comment about
n_tty write_chan() in commit 14b54e39 ("USB: serial: remove
changelogs and old todo entries")).

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Drop the redundant struct usb_serial pointer from the driver port data.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Use the BIT() macro instead of open coding.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Clean up comment style, remove some stale or redundant comments and drop
superfluous white space.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Drop the separate Kconfig symbol for Xircom / Entrega and always include
support in the keyspan_pda driver.

Note that all configs that enabled CONFIG_USB_SERIAL_XIRCOM also enable
CONFIG_USB_SERIAL_KEYSPAN_PDA.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Use the port write fifo and generic chars_and_buffer and write_room
implementations when writing. This not only allows for more efficient
transfers, but more importantly fixes the remaining issues related to
the conservative write_room() implementation which could prevent the
line discipline from making forward progress (e.g. waiting for n > 1
bytes of space to become available).

Note that this also allows using the driver for the system console
without dropping data when the write URB is busy (including when adding
carriage return on line feed).
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Increase the transmitter threshold so that writing isn't resumed until
128 bytes are available in the device buffer thereby allowing for larger
and more efficient transfers.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix stalled writes by checking the available buffer space after
requesting an unthrottle notification in case the device buffer is
already empty so that no notification is ever sent (e.g. when doing
single character writes).

This also means we can drop the room query from write() which was
conditioned on in_interrupt() and prevented writing using this driver
from atomic contexts (e.g. PPP).
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add helper to retrieve the available device transfer-buffer space.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The driver did not update its view of the available device buffer space
until write() was called in task context. This meant that write_room()
would return 0 even after the device had sent a write-unthrottle
notification, something which could lead to blocked writers not being
woken up (e.g. when using OPOST).

Note that we must also request an unthrottle notification is case a
write() request fills the device buffer exactly.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The driver's transmit-unthrottle work was never flushed on disconnect,
something which could lead to the driver port data being freed while the
unthrottle work is still scheduled.

Fix this by cancelling the unthrottle work when shutting down the port.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The driver's deferred write wakeup was never flushed on disconnect,
something which could lead to the driver port data being freed while the
wakeup work is still scheduled.

Fix this by using the usb-serial write wakeup which gets cancelled
properly on disconnect.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Make sure to clear the write-busy flag also in case no new data was
submitted due to lack of device buffer space so that writing is
resumed once space again becomes available.

Fixes: 507ca9bc ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.")
Cc: stable <stable@vger.kernel.org>     # 2.6.13
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The write() callback can be called in interrupt context (e.g. when used
as a console) so interrupts must be disabled while holding the port lock
to prevent a possible deadlock.

Fixes: e81ee637 ("usb-serial: possible irq lock inversion (PPP vs. usb/serial)")
Fixes: 507ca9bc ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.")
Cc: stable <stable@vger.kernel.org>     # 2.6.19
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Commit c528fcb1 ("USB: serial: keyspan_pda: fix receive sanity
checks") broke write-unthrottle handling by dropping well-formed
unthrottle-interrupt packets which are precisely two bytes long. This
could lead to blocked writers not being woken up when buffer space again
becomes available.

Instead, stop unconditionally printing the third byte which is
(presumably) only valid on modem-line changes.

Fixes: c528fcb1 ("USB: serial: keyspan_pda: fix receive sanity checks")
Cc: stable <stable@vger.kernel.org>     # 4.11
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

A break is not needed if it is preceded by a return.
Signed-off-by: NTom Rix <trix@redhat.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated or the context be conveyed in an argument passed by the
caller, which usually knows the context.

The debug printk() in digi_write() prints in_interrupt() as context
information. This information is imprecise as it does not distinguish
between hard-IRQ or disabled bottom half and it does not consider
disabled interrupts or preemption. It is not really helpful.

Remove the in_interrupt() printout.
Signed-off-by: NAhmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20201026140313.dpg3hkhkje2os4hw@linutronix.de
[ johan: amend commit message ]
Signed-off-by: NJohan Hovold <johan@kernel.org>

Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.

Remove the quote operator # from compiler_attributes.h __section macro.

Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.

Conversion done using the script at:

    https://lore.kernel.org/lkml/75393e5ddc272dc7403de74d645e6c6e0f4e70eb.camel@perches.com/2-convert_section.plSigned-off-by: NJoe Perches <joe@perches.com>
Reviewed-by: NNick Desaulniers <ndesaulniers@gooogle.com>
Reviewed-by: NMiguel Ojeda <ojeda@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

tid_addr is not a "pointer to (pointer to int in userspace)"; it is in
fact a "pointer to (pointer to int in userspace) in userspace".  So
sparse rightfully complains about passing a kernel pointer to
put_user().
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 453431a5 ("mm, treewide: rename kzfree() to
kfree_sensitive()") renamed kzfree() to kfree_sensitive(),
but it left a compatibility definition of kzfree() to avoid
being too disruptive.

Since then a few more instances of kzfree() have slipped in.

Just get rid of them and remove the compatibility definition
once and for all.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If set, use the environment variable GIT_DIR to change the default .git
location of the kernel git tree.

If GIT_DIR is unset, keep using the current ".git" default.

Link: https://lkml.kernel.org/r/c5e23b45562373d632fccb8bc04e563abba4dd1d.camel@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Tested-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull timer fixes from Thomas Gleixner:
 "A time namespace fix and a matching selftest. The futex absolute
  timeouts which are based on CLOCK_MONOTONIC require time namespace
  corrected. This was missed in the original time namesapce support"

* tag 'timers-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftests/timens: Add a test for futex()
  futex: Adjust absolute futex timeouts with per time namespace offset

Pull scheduler fixes from Thomas Gleixner:
 "Two scheduler fixes:

   - A trivial build fix for sched_feat() to compile correctly with
     CONFIG_JUMP_LABEL=n

   - Replace a zero lenght array with a flexible array"

* tag 'sched-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/features: Fix !CONFIG_JUMP_LABEL case
  sched: Replace zero-length array with flexible-array

Pull perf fix from Thomas Gleixner:
 "A single fix to compute the field offset of the SNOOPX bit in the data
  source bitmask of perf events correctly"

* tag 'perf-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: correct SNOOPX field offset

Pull locking fix from Thomas Gleixner:
 "Just a trivial fix for kernel-doc warnings"

* tag 'locking-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/seqlocks: Fix kernel-doc warnings

Pull NTB fixes from Jon Mason.

* tag 'ntb-5.10' of git://github.com/jonmason/ntb:
  NTB: Use struct_size() helper in devm_kzalloc()
  ntb: intel: Fix memleak in intel_ntb_pci_probe
  NTB: hw: amd: fix an issue about leak system resources

Pull i2c fix from Wolfram Sang:
 "Regression fix for rc1 and stable kernels as well"

* 'i2c/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: core: Restore acpi_walk_dep_device_list() getting called after registering the ACPI i2c devs