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>

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>

Commit 21653a41 ("i2c: core: Call i2c_acpi_install_space_handler()
before i2c_acpi_register_devices()")'s intention was to only move the
acpi_install_address_space_handler() call to the point before where
the ACPI declared i2c-children of the adapter where instantiated by
i2c_acpi_register_devices().

But i2c_acpi_install_space_handler() had a call to
acpi_walk_dep_device_list() hidden (that is I missed it) at the end
of it, so as an unwanted side-effect now acpi_walk_dep_device_list()
was also being called before i2c_acpi_register_devices().

Move the acpi_walk_dep_device_list() call to the end of
i2c_acpi_register_devices(), so that it is once again called *after*
the i2c_client-s hanging of the adapter have been created.

This fixes the Microsoft Surface Go 2 hanging at boot.

Fixes: 21653a41 ("i2c: core: Call i2c_acpi_install_space_handler() before i2c_acpi_register_devices()")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=209627Reported-by: NRainer Finke <rainer@finke.cc>
Reported-by: NKieran Bingham <kieran.bingham@ideasonboard.com>
Suggested-by: NMaximilian Luz <luzmaximilian@gmail.com>
Tested-by: NKieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NWolfram Sang <wsa@kernel.org>

Non-cryptographic PRNGs may have great statistical properties, but
are usually trivially predictable to someone who knows the algorithm,
given a small sample of their output.  An LFSR like prandom_u32() is
particularly simple, even if the sample is widely scattered bits.

It turns out the network stack uses prandom_u32() for some things like
random port numbers which it would prefer are *not* trivially predictable.
Predictability led to a practical DNS spoofing attack.  Oops.

This patch replaces the LFSR with a homebrew cryptographic PRNG based
on the SipHash round function, which is in turn seeded with 128 bits
of strong random key.  (The authors of SipHash have *not* been consulted
about this abuse of their algorithm.)  Speed is prioritized over security;
attacks are rare, while performance is always wanted.

Replacing all callers of prandom_u32() is the quick fix.
Whether to reinstate a weaker PRNG for uses which can tolerate it
is an open question.

Commit f227e3ec ("random32: update the net random state on interrupt
and activity") was an earlier attempt at a solution.  This patch replaces
it.
Reported-by: NAmit Klein <aksecurity@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: tytso@mit.edu
Cc: Florian Westphal <fw@strlen.de>
Cc: Marc Plumb <lkml.mplumb@gmail.com>
Fixes: f227e3ec ("random32: update the net random state on interrupt and activity")
Signed-off-by: NGeorge Spelvin <lkml@sdf.org>
Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
[ willy: partial reversal of f227e3ec; moved SIPROUND definitions
  to prandom.h for later use; merged George's prandom_seed() proposal;
  inlined siprand_u32(); replaced the net_rand_state[] array with 4
  members to fix a build issue; cosmetic cleanups to make checkpatch
  happy; fixed RANDOM32_SELFTEST build ]
Signed-off-by: NWilly Tarreau <w@1wt.eu>

I tested this driver on my HP PA-RISC C3000 workstation and it does
work with the built-in TEAC CD-532E-B CD-ROM drive.
So drop the TODO item and adjust the file header.
Signed-off-by: NHelge Deller <deller@gmx.de>

Some functions have different names between their prototypes
and the kernel-doc markup.
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We've had several complaints about a 10s reconnect delay (the default)
when there was an error while there is connectivity to a subsystem.
The max_reconnects and reconnect_delay are set in common code prior to
calling the transport to create the controller.

This change checks if the default reconnect delay is being used, and if
so, it adjusts it to a shorter period (2s) for the nvme-fc transport.
It does so by calculating the controller loss tmo window, changing the
value of the reconnect delay, and then recalculating the maximum number
of reconnect attempts allowed.
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

On reconnect, the code currently does not freeze the controller before
possibly updating the number hw queues for the controller.

Add the freeze before updating the number of hw queues.  Note: the queues
are already started and remain started through the reconnect.
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The loop that backs out of hw io queue creation continues through index
0, which corresponds to the admin queue as well.

Fix the loop so it only proceeds through indexes 1..n which correspond to
I/O queues.
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Currently, an I/O timeout unconditionally invokes
nvme_fc_error_recovery() which checks for LIVE or CONNECTING state.  If
live, the routine resets the controller which initiates a reconnect -
which is valid.  If CONNECTING, err_work is scheduled.  Err_work then
calls the terminate_io routine, which also checks for CONNECTING and
noops any further action on outstanding I/O.  The result is nothing
happened to the timed out io.  As such, if the command was dropped on
the wire, it will never timeout / complete, and the connect process
will hang.

Change the behavior of the io timeout routine to unconditionally abort
the I/O.  I/O completion handling will note that an io failed due to an
abort and will terminate the connection / association as needed.  If the
abort was unable to happen, continue with a call to
nvme_fc_error_recovery(). To ensure something different happens in
nvme_fc_error_recovery() rework it so at it will abort all I/Os on the
association to force a failure.

As I/O aborts now may occur outside of delete_association, counting for
completion must be wary and only count those aborted during
delete_association when TERMIO is set on the controller.
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Unmasking an event channel with fifo events channels being used can
require a hypercall to be made, so try to avoid that by checking
whether the event channel was really masked.
Suggested-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NJan Beulich <jbeulich@suse.com>
Link: https://lore.kernel.org/r/20201022094907.28560-5-jgross@suse.comSigned-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>

xen_debug_interrupt() is specific to 2-level event handling. So don't
register it with fifo event handling being active.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NJan Beulich <jbeulich@suse.com>
Link: https://lore.kernel.org/r/20201022094907.28560-4-jgross@suse.comSigned-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>

The struct irq_info of Xen's event handling is used only for two
evtchn_ops functions outside of events_base.c. Those two functions
can easily be switched to avoid that usage.

This allows to make struct irq_info and its related access functions
private to events_base.c.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NJan Beulich <jbeulich@suse.com>
Link: https://lore.kernel.org/r/20201022094907.28560-3-jgross@suse.comSigned-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>

With the switch to the lateeoi model for interdomain event channels
some functions are no longer in use. Remove them.
Suggested-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NJan Beulich <jbeulich@suse.com>
Link: https://lore.kernel.org/r/20201022094907.28560-2-jgross@suse.comSigned-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>

When starting a HP machine with HIL driver but without an HIL keyboard
or HIL mouse attached, it may happen that data written to the HIL loop
gets stuck (e.g. because the transaction queue is full).  Usually one
will then have to reboot the machine because all you see is and endless
output of:
 Transaction add failed: transaction already queued?

In the higher layers hp_sdc_enqueue_transaction() is called to queued up
a HIL packet. This function returns an error code, and this patch adds
the necessary checks for this return code and disables the HIL driver if
further packets can't be sent.

Tested on a HP 730 and a HP 715/64 machine.
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org>

A break following a return statement is pointless, so drop all of
the breaks following return statements from this file.
Signed-off-by: NTom Rix <trix@redhat.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

A break following a return statement is pointless, so drop it.
Signed-off-by: NTom Rix <trix@redhat.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

All avs drivers have now been moved to their corresponding soc specific
directories. Additionally, they don't depend on the POWER_AVS Kconfig
anymore. Therefore, let's simply drop the drivers/power/avs directory
altogether.

Cc: Nishanth Menon <nm@ti.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The block layer provides special status codes when requests go beyond
the zone resource limits. Use these codes instead of the generic IOERR
for requests that exceed the max active or open limits the null_blk
device was configured with so that applications know how these special
conditions should be handled.
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NNiklas Cassel <niklas.cassel@wdc.com>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>