When DMA is enabled the receive handler runs in a threaded handler, but
the primary handler up until very recently neither disabled interrupts
in the device or used IRQF_ONESHOT. This would lead to a deadlock if an
interrupt comes in while the threaded receive handler is running under
the port lock.
Commit ad76768124 ("serial: stm32: fix a deadlock condition with
wakeup event") claimed to fix an unrelated deadlock, but unfortunately
also disabled interrupts in the threaded handler. While this prevents
the deadlock mentioned in the previous paragraph it also defeats the
purpose of using a threaded handler in the first place.
Fix this by making the interrupt one-shot and not disabling interrupts
in the threaded handler.
Note that (receive) DMA must not be used for a console port as the
threaded handler could be interrupted while holding the port lock,
something which could lead to a deadlock in case an interrupt handler
ends up calling printk.
Fixes: ad76768124 ("serial: stm32: fix a deadlock condition with wakeup event")
Fixes: 3489187204 ("serial: stm32: adding dma support")
Cc: stable@vger.kernel.org # 4.9
Cc: Alexandre TORGUE <alexandre.torgue@st.com>
Cc: Gerald Baeza <gerald.baeza@st.com>
Reviewed-by: Valentin Caron<valentin.caron@foss.st.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The uart_unlock_and_check_sysrq() helper can be used to defer processing
of sysrq until the interrupt handler has released the port lock and is
about to return.
Since commit 81e2073c17 ("genirq: Disable interrupts for force
threaded handlers") interrupt handlers that are not explicitly requested
as threaded are always called with interrupts disabled and there is no
need to save the interrupt state when taking the port lock.
Instead of adding another sysrq helper for when the interrupt state has
not needlessly been saved, drop the state parameter from
uart_unlock_and_check_sysrq() and update its callers to no longer
explicitly disable interrupts in their interrupt handlers.
Cc: Joel Stanley <joel@jms.id.au>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The variable count is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and can be removed.
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Addresses-Coverity: ("Unused value")
Link: https://lore.kernel.org/r/20210420105718.377086-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the transition to hrtimers there is no more need to set a minimum
RX timeout to work around latency issues.
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu>
Link: https://lore.kernel.org/r/20210415093547.21639-1-uli+renesas@fpond.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are a lot of tty-core-only functions that are listed in
include/linux/tty.h. Move them to drivers/tty/tty.h so that no one else
can accidentally call them or think that they are public functions.
Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-14-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The flow change and restricted_tty_write() logic is internal to the tty
core only, so move it out of the include/linux/tty.h file.
Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-12-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The functions tty_audit_add_data() and tty_audit_tiocsti() are local to
the tty core code, and do not need to be in a "kernel-wide" header file
so move them to drivers/tty/tty.h
Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-9-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No one is calling this macro, and no one should, so remove it from the
.h file.
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-3-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are a number of functions and #defines in include/linux/tty.h that
do not belong there as they are private to the tty core code.
Create an initial drivers/tty/tty.h file and copy the odd "tty logging"
macros into it to seed the file with some initial things that we know
nothing outside of the tty core should be calling.
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These correspond to the existing lpc_address, sirq, and sirq_polarity
sysfs attributes; the second element of aspeed,lpc-interrupts provides
a replacement for the deprecated aspeed,sirq-polarity-sense property.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210412034712.16778-5-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These allow describing all the Aspeed VUART attributes currently
available via sysfs. aspeed,lpc-interrupts provides a replacement for
the deprecated aspeed,sirq-polarity-sense property.
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210412034712.16778-4-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This splits dedicated aspeed_vuart_set_{sirq,lpc_address}() functions
out of the sysfs store functions in preparation for adding DT
properties that will be poking the same registers. While we're at it,
these functions now provide some basic bounds-checking on their
arguments.
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210412034712.16778-3-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This property ties SIRQ polarity to SCU register bits that don't
necessarily have any direct relationship to it; the only use of it was
removed in commit c82bf6e133 ("ARM: aspeed: g5: Do not set sirq
polarity").
Reviewed-by: Joel Stanley <joel@jms.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210412034712.16778-2-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sparse tool complains as follows:
drivers/tty/hvc/hvc_udbg.c:20:19: warning:
symbol 'hvc_udbg_dev' was not declared. Should it be static?
This symbol is not used outside of hvc_udbg.c, so this
commit marks it static.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20210407125826.4139130-1-yukuai3@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 30004ac9c0 ("tty: add tty_struct->dev pointer to corresponding
device instance") added a struct device pointer field to struct
tty_struct which was populated with the corresponding tty class device
during initialisation.
Unfortunately, not all ttys have a class device (e.g. pseudoterminals
and serdev) in which case the device pointer will be set to NULL,
something which have bit driver authors over the years.
In retrospect perhaps this field should never have been added, but let's
at least document the current behaviour.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210409073512.6876-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Link: https://lore.kernel.org/r/20210410035048.11466-1-cuibixuan@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Include the generic serial.yaml dtschema so the child node like
"bluetooth" will be properly matched:
arch/arm/boot/dts/exynos4210-universal_c210.dt.yaml:
serial@13800000: 'bluetooth' does not match any of the regexes: 'pinctrl-[0-9]+'
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20210409172027.11296-1-krzysztof.kozlowski@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers can return -ENOIOCTLCMD when an ioctl is not recognised to tell
the upper layers to continue looking for a handler.
This is not the case for the RS485 and ISO7816 ioctls whose handlers
should return -ENOTTY directly in case a serial driver does not
implement the corresponding methods.
Fixes: a5f276f10f ("serial_core: Handle TIOC[GS]RS485 ioctls.")
Fixes: ad8c0eaa0a ("tty/serial_core: add ISO7816 infrastructure")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-9-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 5099d234a5 ("serial_core: switch to ->[sg]et_serial()")
the serial structure passed to uart_get_info() has already have been
cleared by the tty layer so drop the redundant memset.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-8-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Callout devices are long-gone, but the ASYNC_SPLIT_TERMIOS flag was
never added to the deprecation mask.
Add it so that a warning is printed if it is ever used.
Fixes: 8a8ae62f82 ("tty: warn on deprecated serial flags")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-7-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Factor out the deprecated serial flags handling and tty-operation check
shared with the compat TIOCSSERIAL handler.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-6-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use pr_warn_ratelimited() when warning about deprecated serial flags
instead of open coding.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers should return -ENOTTY ("Inappropriate I/O control operation")
when an ioctl isn't supported, while -EINVAL is used for invalid
arguments.
Support for termiox was added by commit 1d65b4a088 ("tty: Add
termiox") in 2008 but no driver support ever followed and it was
recently ripped out by commit e0efb3168d ("tty: Remove dead termiox
code").
Fix the return value for the unsupported termiox ioctls, which have
always returned -EINVAL, by explicitly returning -ENOTTY rather than
removing them completely and falling back to the default unrecognised-
ioctl handling.
Fixes: 1d65b4a088 ("tty: Add termiox")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drivers should return -ENOTTY ("Inappropriate I/O control operation")
when an ioctl isn't supported, while -EINVAL is used for invalid
arguments.
Fix up the TIOCMGET, TIOCMSET and TIOCGICOUNT helpers which returned
-EINVAL when a tty driver did not implement the corresponding
operations.
Note that the TIOCMGET and TIOCMSET helpers predate git and do not get a
corresponding Fixes tag below.
Fixes: d281da7ff6 ("tty: Make tiocgicount a handler")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some kernel-internal ASYNC flags have been superseded by tty-port flags
and should no longer be used by kernel drivers.
Fix the misspelled "__KERNEL__" compile guards which failed their sole
purpose to break out-of-tree drivers that have not yet been updated.
Fixes: 5c0517fefc ("tty: core: Undefine ASYNC_* flags superceded by TTY_PORT* flags")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix coding style issues of block comments, reported by checkpatch.pl.
Besides, do some expression optimization for the sentenses.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1617779210-51576-5-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port close_delay and closing_wait parameters have already been by
tty_port_init() so drop the redundant driver initialisation to the
default values.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-17-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port close_delay and closing_wait parameters have already been by
tty_port_init() so drop the redundant driver initialisation to the
default values.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-16-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Changing the port type and closing_wait parameter are privileged
operations so make sure to return -EPERM if a regular user tries to
change them.
Note that the closing_wait parameter would not actually have been
changed but the return value did not indicate that.
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-15-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port close_delay and closing wait parameters set by TIOCSSERIAL are
specified in jiffies, while the values returned by TIOCGSERIAL are
specified in centiseconds.
Add the missing conversions so that TIOCSSERIAL works as expected also
when HZ is not 100.
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-14-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
TIOCSSERIAL is a horrid, underspecified, legacy interface which for most
serial devices is only useful for setting the close_delay and
closing_wait parameters.
A non-privileged user has only ever been able to set the since long
deprecated ASYNC_SPD flags and trying to change any other *supported*
feature should result in -EPERM being returned. Setting the current
values for any supported features should return success.
Fix the moxa implementation which was returning -EPERM also for a
privileged user when trying to change certain unsupported parameters and
instead return success consistently.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-13-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The port close_delay parameter set by TIOCSSERIAL is specified in
jiffies, while the value returned by TIOCGSERIAL is specified in
centiseconds.
Add the missing conversions so that TIOCGSERIAL works as expected also
when HZ is not 100.
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-11-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tty-port close_delay and closing_wait parameters set by TIOCSSERIAL
are specified in jiffies, while the values returned by TIOCGSERIAL are
specified in centiseconds.
Add the missing conversions so that TIOCSSERIAL works as expected also
if this code is ever reused on a system where HZ is not 100.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-10-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Changing the port closing_wait parameter is a privileged operation.
Add the missing check to TIOCSSERIAL so that -EPERM is returned in case
an unprivileged user tries to change the closing-wait setting.
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-9-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
TIOCSSERIAL is a horrid, underspecified, legacy interface which for most
serial devices is only useful for setting the close_delay and
closing_wait parameters.
The xmit_fifo_size parameter could be used to set the hardware transmit
fifo size of a legacy UART when it could not be detected, but the
interface is limited to eight bits and should be left unset when not
used.
Similarly, baud_base could be used to set the UART base clock when it
could not be detected but might as well be left unset when it is not
known.
The type parameter could be used to set the UART type, but is
better left unspecified (type unknown) when it isn't used.
Note that some applications have historically expected TIOCGSERIAL to be
implemented, but judging from the Debian sources, the port type not
being PORT_UNKNOWN is only used to check for the existence of legacy
serial ports (ttySn). Notably USB serial drivers like ftdi_sio have been
using PORT_UNKNOWN for twenty years without any problems.
Drop the bogus values provided by the greybus implementation.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407102334.32361-8-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Johan Hovold