MSI needs it as well.
Should have no practical impact, though, as DMA is always available on
the Quark. But given the few users of pci_alloc_irq_vectors so far, this
incorrect pattern may spread otherwise.
Fixes: 3f3a46951e ("serial: 8250_lpss: set PCI master only for private DMA")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a UART has dedicated RTS/CTS pins, and hardware control flow is
disabled (or AUTORTS is not yet effective), changing any serial port
configuration deasserts RTS, as .set_termios() calls sci_init_pins().
To fix this, consider the current (AUTO)RTS state when (re)initializing
the pins. Note that for SCIFA/SCIFB, AUTORTS needs explicit
configuration of the RTS# pin function, while (H)SCIF handles this
automatically.
Fixes: d2b9775d79 ("serial: sh-sci: Correct pin initialization on (H)SCIF")
Fixes: e9d7a45a03 ("serial: sh-sci: Add pin initialization for SCIFA/SCIFB")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When changing hardware control flow for a UART with dedicated RTS/CTS
pins, the new AUTORTS state is not immediately reflected in the
hardware, but only when RTS is raised. However, the serial core does
not call .set_mctrl() after .set_termios(), hence AUTORTS may only
become effective when the port is closed, and reopened later.
Note that this problem does not happen when manually using stty to
change CRTSCTS, as AUTORTS will work fine on next open.
To fix this, call .set_mctrl() from .set_termios() when dedicated
RTS/CTS pins are present, to refresh the AUTORTS or RTS state.
This is similar to what other drivers supporting AUTORTS do (e.g.
omap-serial).
Reported-by: Baumann, Christoph (C.) <cbaumann@visteon.com>
Fixes: 33f50ffc25 ("serial: sh-sci: Fix support for hardware-assisted RTS/CTS")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the .set_termios() callback resets the UART, it first waits (busy
loops) until all characters in the transmit FIFO have been transmitted,
to prevent a port configuration change from impacting these characters.
However, if the UART has dedicated RTS/CTS hardware flow control
enabled, these characters may have been stuck in the FIFO due to CTS not
being asserted by the remote side.
- When a new user opens the port, .set_termios() is called while
transmission is still disabled, leading to an infinite loop:
NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s!
- When an active user changes port configuration without waiting for
the draining of the transmit FIFO, this may also block indefinitely,
until CTS is asserted by the remote side.
This has been observed with SCIFA (on r8a7740/armadillo), and SCIFB and
HSCIF (on r8a7791/koelsch).
To fix this, remove the code that waits for the draining of the transmit
FIFO.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hvc_remove() takes a spin lock first then acquires the console
semaphore. This situation can easily lead to a deadlock scenario
where we call scheduler with spin lock held.
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Free any saved termios data when registering a tty device so that the
termios state is reset when reusing a minor number.
This is useful for hot-pluggable buses such as USB where it does not
make much sense to reuse saved termios data from an unrelated device
when a new device is later plugged in.
This specifically avoids a situation where the new device does not have
the carrier-detect signal wired, but the saved termios state has CLOCAL
cleared, effectively preventing the port from being opened in blocking
mode as noted by Jan Kundrát <jan.kundrat@cesnet.cz>.
Note that clearing the saved data at deregistration would not work as
the device could still be open.
Also note that the termios data is not reset for drivers with
TTY_DRIVER_DYNAMIC_ALLOC set (e.g. legacy pty) as their character device
is registered at driver registration and could theoretically already
have been opened (and pty termios state is never saved anyway).
Reported-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drop comments about tty-driver termios_locked structures, which have
been outdated since commit fe6e29fdb1 ("tty: simplify ktermios
allocation").
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tty class device is currently not registered until after the
character device has been registered thereby leaving a small window
were a racing open could end up with a NULL tty->dev pointer due to the
class-device lookup failing in alloc_tty_struct.
Close this race by registering the class device before the character
device while making sure to defer the user-space uevent notification
until after the character device has been registered.
Note that some tty drivers expect a valid tty->dev and would misbehave
or crash otherwise. Some line disciplines also currently dereference the
class device unconditionally despite the fact that not every tty is
guaranteed to have one (Unix98 pty), but this is being fixed separately.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tty/serial driver fixes from Greg KH:
"Here are some tty and serial driver fixes for 4.11-rc4.
One of these fix a long-standing issue in the ldisc code that was
found by Dmitry Vyukov with his great fuzzing work. The other fixes
resolve other reported issues, and there is one revert of a patch in
4.11-rc1 that wasn't correct.
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-4.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
tty: fix data race in tty_ldisc_ref_wait()
tty: don't panic on OOM in tty_set_ldisc()
Revert "tty: serial: pl011: add ttyAMA for matching pl011 console"
tty: acpi/spcr: QDF2400 E44 checks for wrong OEM revision
serial: 8250_dw: Fix breakage when HAVE_CLK=n
serial: 8250_dw: Honor clk_round_rate errors in dw8250_set_termios
The modalias sysfs attr is lacking a newline for DT aliases on platform
devices. The macio and ibmebus correctly add the newline, but open code it.
Introduce a new function, of_device_modalias(), that fills the buffer with
the modalias including the newline and update users of the old
of_device_get_modalias function.
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull GPIO fixes from Linus Walleij:
"Here is the first set of GPIO fixes for 4.11. It was delayed a bit
beacuse I was chicken when linux-next was not rotating last week.
This hits the ST serial driver in drivers/tty/serial and that has an
ACK from Greg, he suggested to keep the old GPIO fwnode API around to
smoothen things in the merge Windod and those have now served their
purpose so we take them out and convert the last driver to the new
API.
Apart from that it's fixes as usual.
Summary:
- set the parent on the Altera A10SR driver, also fix high level
IRQs.
- fix error path on the mockup driver.
- compilation noise about unused functions fixed.
- fix missed interrupts on the MCP23S08 expander, this is also tagged
for stable.
- retire the interrim helpers devm_get_gpiod_from_child() used to
smoothen merging in the merge window"
* tag 'gpio-v4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
gpio:mcp23s08 Fixed missing interrupts
serial: st-asc: Use new GPIOD API to obtain RTS pin
gpio: altera: Use handle_level_irq when configured as a level_high
gpio: xgene: mark PM functions as __maybe_unused
gpio: mockup: return -EFAULT if copy_from_user() fails
gpio: altera-a10sr: Set gpio_chip parent property
As of commit bb475230b8 ("reset: make optional functions really
optional"), the reset framework API calls use NULL pointers to describe
optional, non-present reset controls.
This allows to return errors from devm_reset_control_get_optional and to
call reset_control_(de)assert unconditionally.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Coverity complains about uart_state checks in polling functions. And it
is indeed correct. We do something like this:
struct uart_state *state = drv->state + line;
if (!state)
return;
Adding 'line' to drv->state would move the potential NULL pointer to
something near NULL and the check is useless. Even if we checked pure
drv->state, nothing guarantees it is not freed and NULLed after the
check. So if the only user of this interface (kgdboc) needs to assure
something, this is neither the correct thing, nor place to do so.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fintek F81866 supports baud rates higher than 115200 but needs to raise
it's clock speed from 1.84 to 14.76 MHz.
This is eight times faster, so gives 921600 as resulting baud_base.
F81866 clock register 0xf2:
Bit 7-2 reserved
Bit 1-0 00: 1.8432MHz
01: 18.432MHz
10: 24MHz
11: 14.769MHz
Signed-off-by: Lukas Redlinger <rel+kernel@agilox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While using emacs, cat or others' commands in konsole with recent
kernels, I have met many times that CTRL-C freeze konsole. After
konsole freeze I can't type anything, then I have to open a new one,
it is very annoying.
See bug report:
https://bugs.kde.org/show_bug.cgi?id=175283
The platform in that bug report is Solaris, but now the pty in linux
has the same problem or the same behavior as Solaris :)
It has high possibility to trigger the problem follow steps below:
Note: In my test, BigFile is a text file whose size is bigger than 1G
1:open konsole
1:cat BigFile
2:CTRL-C
After some digging, I find out the reason is that commit 1d1d14da12
("pty: Fix buffer flush deadlock") changes the behavior of pty_flush_buffer.
Thread A Thread B
-------- --------
1:n_tty_poll return POLLIN
2:CTRL-C trigger pty_flush_buffer
tty_buffer_flush
n_tty_flush_buffer
3:attempt to check count of chars:
ioctl(fd, TIOCINQ, &available)
available is equal to 0
4:read(fd, buffer, avaiable)
return 0
5:konsole close fd
Yes, I know we could use the same patch included in the BUG report as
a workaround for linux platform too. But I think the data in ldisc is
belong to application of another side, we shouldn't clear it when we
want to flush write buffer of this side in pty_flush_buffer. So I think
it is better to disable ldisc flush in pty_flush_buffer, because its new
hehavior bring no benefit except that it mess up the behavior between
POLLIN, and TIOCINQ or FIONREAD.
Also I find no flush_buffer function in others' tty driver has the
same behavior as current pty_flush_buffer.
Fixes: 1d1d14da12 ("pty: Fix buffer flush deadlock")
CC: stable@vger.kernel.org # v4.0+
Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The number of uartlites should be set by a kernel parameter instead of
using a #define. This allows the user to set the number of uartlites
using only kconfig and not modifying kernel source.
The uartlite is used by FPGAs that support a basically unlimited number
of uarts so limiting it at 16 dosn't make sense as users might need more
than that.
Signed-off-by: Sam Povilus <kernel.development@povil.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The core handles the clocking now. Remove the clock disable in
suspend. In resume we enable the clocks and disable after register
write.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nios2 currently uses its own early printk implementation, rather than
using unified earlycon support to show boot messages on altera_jtaguart
(and altera_uart for that matter).
Add earlycon support to altera_jtaguart so that other archs may use it. Also,
this will allow the early printk implementation in arch/nios2 to eventually be
removed in a future patch.
Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of using a private copy of struct net_device_stats in struct
gsm_mux_net, use stats from struct net_device. Also remove
the now unnecessary .ndo_get_stats function.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jan Kiszka
Geert Uytterhoeven
Lee Jones
Lionel Debieve
Denis Kirjanov
Johan Hovold
Greg Kroah-Hartman
Ingo Molnar
Linus Torvalds
Rob Herring
Philipp Zabel
Jiri Slaby
Lukas Redlinger
Peter Hurley
Wang YanQing
Sam Povilus
Shubhrajyoti Datta
Tobias Klauser