Since forever, gpm was this code's only user, and it overrides the table on
start so the default was never seen -- until Bill Allombert's "consolation"
came in.  The in-kernel set is "A-Za-z0-9_" which fails to catch typical
file names, etc.  Let's change this to gpm's conservative default, ie
"-A-Za-z0-9_./"; most terminals include more, for example xfce4-terminal has
"-A-Za-z0-9,./?%&#:_=+@~".

There's some discussion at https://bugs.debian.org/846587Signed-off-by: NAdam Borowski <kilobyte@angband.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Reduce RX DMA start latency for the first reception when port is opened
for reading. Instead of waiting for an interrupt signaling data on RX
FIFO or data too old on RX FIFO, start RX DMA immediately when the
serial port is opened for reading.

Before this patch, the average RX DMA latency for the first reception
was 42489 microseconds with a standard deviation of 25721 microseconds
in 36 samples.

After the patch the average RX DMA latency for the first reception, when
the serial port is opened for reading, is 653 microseconds with a
standard deviation of 294 microseconds in 36 samples.
Signed-off-by: NPeter Senna Tschudin <peter.senna@collabora.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make sure to actually suspend the device before returning after a failed
(or deferred) probe.

Note that autosuspend must be disabled before runtime pm is disabled in
order to balance the usage count due to a negative autosuspend delay as
well as to make the final put suspend the device synchronously.

Fixes: 388bc262 ("omap-serial: Fix the error handling in the omap_serial probe")
Cc: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Acked-by: NTony Lindgren <tony@atomide.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

An unbalanced and misplaced synchronous put was used to suspend the
device on driver unbind, something which with a likewise misplaced
pm_runtime_disable leads to external aborts when an open port is being
removed.

Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa024010
...
[<c046e760>] (serial_omap_set_mctrl) from [<c046a064>] (uart_update_mctrl+0x50/0x60)
[<c046a064>] (uart_update_mctrl) from [<c046a400>] (uart_shutdown+0xbc/0x138)
[<c046a400>] (uart_shutdown) from [<c046bd2c>] (uart_hangup+0x94/0x190)
[<c046bd2c>] (uart_hangup) from [<c045b760>] (__tty_hangup+0x404/0x41c)
[<c045b760>] (__tty_hangup) from [<c045b794>] (tty_vhangup+0x1c/0x20)
[<c045b794>] (tty_vhangup) from [<c046ccc8>] (uart_remove_one_port+0xec/0x260)
[<c046ccc8>] (uart_remove_one_port) from [<c046ef4c>] (serial_omap_remove+0x40/0x60)
[<c046ef4c>] (serial_omap_remove) from [<c04845e8>] (platform_drv_remove+0x34/0x4c)

Fix this up by resuming the device before deregistering the port and by
suspending and disabling runtime pm only after the port has been
removed.

Also make sure to disable autosuspend before disabling runtime pm so
that the usage count is balanced and device actually suspended before
returning.

Note that due to a negative autosuspend delay being set in probe, the
unbalanced put would actually suspend the device on first driver unbind,
while rebinding and again unbinding would result in a negative
power.usage_count.

Fixes: 7e9c8e7d ("serial: omap: make sure to suspend device before remove")
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Acked-by: NTony Lindgren <tony@atomide.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The UPF_BOOT_AUTOCONF flag is needed for proper
flow control support.
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NSebastian Reichel <sre@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Spinlock taken only for dma_map_single() for TX buffer is completely
useless and doesn't protect anything, so remove it to simplify the code.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds missing checks for dma_map_single() failure and proper error
reporting. Although this issue was harmless on ARM architecture, it is always
good to use the DMA mapping API in a proper way. This patch fixes the following
DMA API debug warning:

WARNING: CPU: 1 PID: 3785 at lib/dma-debug.c:1171 check_unmap+0x8a0/0xf28
dma-pl330 121a0000.pdma: DMA-API: device driver failed to check map error[device address=0x000000006e0f9000] [size=4096 bytes] [mapped as single]
Modules linked in:
CPU: 1 PID: 3785 Comm: (agetty) Tainted: G        W       4.11.0-rc1-00137-g07ca963-dirty #59
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24)
[<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0)
[<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180)
[<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50)
[<c01395a4>] (warn_slowpath_fmt) from [<c072a114>] (check_unmap+0x8a0/0xf28)
[<c072a114>] (check_unmap) from [<c072a834>] (debug_dma_unmap_page+0x98/0xc8)
[<c072a834>] (debug_dma_unmap_page) from [<c0803874>] (s3c24xx_serial_shutdown+0x314/0x52c)
[<c0803874>] (s3c24xx_serial_shutdown) from [<c07f5124>] (uart_port_shutdown+0x54/0x88)
[<c07f5124>] (uart_port_shutdown) from [<c07f522c>] (uart_shutdown+0xd4/0x110)
[<c07f522c>] (uart_shutdown) from [<c07f6a8c>] (uart_hangup+0x9c/0x208)
[<c07f6a8c>] (uart_hangup) from [<c07c426c>] (__tty_hangup+0x49c/0x634)
[<c07c426c>] (__tty_hangup) from [<c07c78ac>] (tty_ioctl+0xc88/0x16e4)
[<c07c78ac>] (tty_ioctl) from [<c03b5f2c>] (do_vfs_ioctl+0xc4/0xd10)
[<c03b5f2c>] (do_vfs_ioctl) from [<c03b6bf4>] (SyS_ioctl+0x7c/0x8c)
[<c03b6bf4>] (SyS_ioctl) from [<c010b4a0>] (ret_fast_syscall+0x0/0x3c)
Reported-by: NSeung-Woo Kim <sw0312.kim@samsung.com>
Fixes: 62c37eed ("serial: samsung: add dma reqest/release functions")
CC: stable@vger.kernel.org # v4.10+
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: NShuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Driver should provide its own struct device for all DMA-mapping calls instead
of extracting device pointer from DMA engine channel. Although this is harmless
from the driver operation perspective on ARM architecture, it is always good
to use the DMA mapping API in a proper way. This patch fixes following DMA API
debug warning:

WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1241 check_sync+0x520/0x9f4
samsung-uart 12c20000.serial: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x000000006df0f580] [size=64 bytes]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1-00137-g07ca963 #51
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24)
[<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0)
[<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180)
[<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50)
[<c01395a4>] (warn_slowpath_fmt) from [<c0729058>] (check_sync+0x520/0x9f4)
[<c0729058>] (check_sync) from [<c072967c>] (debug_dma_sync_single_for_device+0x88/0xc8)
[<c072967c>] (debug_dma_sync_single_for_device) from [<c0803c10>] (s3c24xx_serial_start_tx_dma+0x100/0x2f8)
[<c0803c10>] (s3c24xx_serial_start_tx_dma) from [<c0804338>] (s3c24xx_serial_tx_chars+0x198/0x33c)
Reported-by: NSeung-Woo Kim <sw0312.kim@samsung.com>
Fixes: 62c37eed ("serial: samsung: add dma reqest/release functions")
CC: stable@vger.kernel.org # v4.0+
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: NKrzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: NShuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the UART is operated in DTE mode and UCR3_DCD or UCR3_RI are 1 (which
is the reset default) and the opposite side pulls the respective line to
its active level the irq triggers after it is requested in .probe.

These irqs were already disabled in .startup but this might be too late.

Also setup of the UFCR_DCEDTE bit (currently done in .set_termios) is
done very late which is critical as it also controls direction of some
pins.

So setup UFCR_DCEDTE earlier (in .probe) and also disable the broken
irqs in DTE mode there before requesting irqs.
Acked-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@cascardo.eti.br>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On SMP systems, we see a lot of spurious TX interrupts when a
program generates a steady stream of output to the pl011 UART.

The problem can be easily seen when one CPU generates the output
while another CPU handles the pl011 interrupts, and the rate of
output is low enough not to fill the TX FIFO. The problem seems
to be:

    -- CPU a --                        -- CPU b --
   (take port lock)
   pl011_start_tx
      pl011_start_tx_pio
         enable TXIM in REG_IMSC   ->  causes uart tx intr (pl011_int)
         pl011_tx_chars                pl011_int
            ...tx chars, all done...       (wait for port lock)
            pl011_stop_tx                   .
               disable TXIM                 .
    (release port lock)            ->      (take port lock)
                                           check for TXIM, not enabled
                                           (release port lock)
                                           return IRQ_NONE

Enabling the TXIM in pl011_start_tx_pio() causes the interrupt
to be generated and delivered to CPU b, even though pl011_tx_chars()
is able to complete the TX and then disable the tx interrupt.

Fix this by enabling TXIM only after pl011_tx_chars, if it is needed.
pl011_tx_chars will return a boolean indicating whether the TX
interrupts have to be enabled.
Debugged-by: NVijaya Kumar <Vijaya.Kumar@cavium.com>
Signed-off-by: NJayachandran C <jnair@caviumnetworks.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When Power management is disabled then the clocks are not getting
enabled. This patch enables it for the !PM case also.
While at it also pm_runtime_set_active is called before
calling pm_runtime_enable.
Reported-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NShubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since we have port name stored in struct uart_port, we better to use
that one instead of open coding.

This will make it one place source for easier maintenance or
modifications.

While here, replace printk(KERN_INFO ) by pr_info(). It seems last printk()
call in serial_core.c.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add serdev_device_write() a blocking call allowing to transfer
arbitraty amount of data (potentially exceeding amount that
serdev_device_write_buf can process in a single call)

To support that, also add serdev_device_write_wakeup().

Drivers wanting to use full extent of serdev_device_write
functionality are expected to provide serdev_device_write_wakeup() as
a sole handler of .write_wakeup event or call it as a part of driver's
custom .write_wakeup code.

Because serdev_device_write() subroutine is a superset of
serdev_device_write_buf() the patch re-impelements latter is terms of
the former. For drivers wanting to just use serdev_device_write_buf()
.write_wakeup handler is optional.

Cc: cphealy@gmail.com
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: NRob Herring <robh@kernel.org>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

SPRD_TIMEOUT was 256, which is too small to wait until the status
switched to workable in a while loop, so that the earlycon could
not work correctly.
Signed-off-by: NWei Qiao <wei.qiao@spreadtrum.com>
Signed-off-by: NChunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The work-around for the Qualcomm Datacenter Technologies QDF2400
erratum 44 sets the "qdf2400_e44_present" global variable if the
work-around is needed.  However, this check does not happen until after
earlycon is initialized, which means the work-around is not
used, and the console hangs as soon as it displays one character.

Fixes: d8a4995b ("tty: pl011: Work around QDF2400 E44 stuck BUSY bit")
Signed-off-by: NTimur Tabi <timur@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

kbuild test robot reported a non-static variable name collision between
a staging driver and a RapidIO driver, with a generic variable name of
'dbg_level'.

Both drivers should be changed so that they don't use this generic
public variable name.  This patch fixes the RapidIO driver but does not
change the user interface (name) for the module parameter.

  drivers/staging/built-in.o:(.bss+0x109d0): multiple definition of `dbg_level'
  drivers/rapidio/built-in.o:(.bss+0x16c): first defined here

Link: http://lkml.kernel.org/r/ab527fc5-aa3c-4b07-5d48-eef5de703192@infradead.orgSigned-off-by: NRandy Dunlap <rdunlap@infradead.org>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In commit d0aeaa83 ("serial: exar:
split out the exar code from 8250_pci") the exar driver got its own
Kconfig.  However the text for the new option was never changed from
the original 8250_PCI text, and hence it appears confusing when you
get asked the same question twice:

  8250/16550 PCI device support (SERIAL_8250_PCI) [Y/n/m/?] (NEW)
    8250/16550 PCI device support (SERIAL_8250_EXAR) [Y/n/m] (NEW)

Adding to the confusion, is that there is no help text for this new
option to indicate it is specific to a certain family of cards.

Fix both issues at the same time, as well as the space vs. tab issues
introduced in the same commit.

Fixes: d0aeaa83 ("serial: exar: split out the exar code from 8250_pci")
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: NSudip Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A side effect of 89d82324 ("tty/serial: atmel_serial: BUG: stop DMA
from transmitting in stop_tx") is that the console can be called with
TX path disabled. Then the system would hang trying to push charecters
out in atmel_console_putchar().
Signed-off-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Fixes: 89d82324 ("tty/serial: atmel_serial: BUG: stop DMA from transmitting
in stop_tx")
Cc: stable <stable@vger.kernel.org>	#4.4+
Acked-by: NRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If uart_flush_buffer() is called between atmel_tx_dma() and
atmel_complete_tx_dma(), the circular buffer has been cleared, but not
atmel_port->tx_len.
That leads to a circular buffer overflow (dumping (UART_XMIT_SIZE -
atmel_port->tx_len) bytes).
Tested-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: NRichard Genoud <richard.genoud@gmail.com>
Cc: stable <stable@vger.kernel.org> # 3.12+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The reference manual for the i.MX28 recommends to calculate the divisor
as

	divisor = (UARTCLK * 32) / baud rate, rounded to the nearest integer

, so let's do this. For a typical setup of UARTCLK = 24 MHz and baud
rate = 115200 this changes the divisor from 6666 to 6667 and so the
actual baud rate improves from 115211.521 Bd (error ≅ 0.01 %) to
115194.240 Bd (error ≅ 0.005 %).
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The console write code is not entirely race free (e.g. the operations
to disabling the UART interrupts are not atomic) hence locking is
required. This has been become apparent with the PREEMPT RT patchset
applied: With the fully preemptible kernel configuration the system
often ended up in a freeze already at startup.

Disable interrupts and lock using read_lock_irqsave. Try to lock in
the sysrq/oops case, but don't bother if locking fails.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NGreg 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_uart.

Add earlycon support to altera_uart so that other archs may use it.
Also, this (together with the corresponding patch for altera_jtaguart)
will allow the early printk implementation in arch/nios2 to be removed
in a future patch.

Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

BugLink: http://bugs.launchpad.net/bugs/869017

Console blanking is not enabling DPMS power saving (thereby negating any
power-saving benefit), and is simply turning the screen content blank. This
means that any crash output is invisible which is unhelpful on a server
(virtual or otherwise).

Furthermore, CRT burn in concerns should no longer govern the default case.
Affected users could always set consoleblank on the kernel command line.
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Adam Borowski <kilobyte@angband.pl>
Cc: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Using dev_name() as IRQ name during request_irq() might be misleading in
case of serial over PCI. Therefore identify serial port IRQ using
uart_port's name field. This will help mapping IRQs to appropriate
ttySN(where N is the serial port index) instances.
Signed-off-by: NVignesh R <vigneshr@ti.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Introduce a field to store name of uart_port that can be used to easily
identify UART port instances on a system that has more than one UART
instance. The name is of the form ttyXN(eg. ttyS0, ttyAMA0,..) where N
is number that particular UART instance.
This field will be useful when printing debug info for a particular port
or in register IRQs with unique IRQ name. Port name is populated during
uart_add_one_port().
Signed-off-by: NVignesh R <vigneshr@ti.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 4cfffcfa ("irqchip/mips-gic: Fix local interrupts") added
mapping of several local interrupts during initialisation of the gic
driver. This associates virq numbers with these interrupts.
Unfortunately, as not all of the interrupts are mapped in hardware
order, when drivers subsequently request these interrupts they conflict
with the mappings that have already been set up. For example, this
manifests itself in the gic clocksource driver, which fails to probe
with the message:

clocksource: GIC: mask: 0xffffffffffffffff max_cycles: 0x7350c9738,
max_idle_ns: 440795203769 ns
GIC timer IRQ 25 setup failed: -22

This is because virq 25 (the correct IRQ number specified via device
tree) was allocated to the PERFCTR interrupt (and 24 to the timer, 26 to
the FDC). To fix this, map all of these local interrupts in the hardware
order so as to associate their virq numbers with the correct hw
interrupts.

Fixes: 4cfffcfa ("irqchip/mips-gic: Fix local interrupts")
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NMatt Redfearn <matt.redfearn@imgtec.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

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: 3f3a4695 ("serial: 8250_lpss: set PCI master only for private DMA")
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NGreg 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: d2b9775d ("serial: sh-sci: Correct pin initialization on (H)SCIF")
Fixes: e9d7a45a ("serial: sh-sci: Add pin initialization for SCIFA/SCIFB")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg 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: NBaumann, Christoph (C.) <cbaumann@visteon.com>
Fixes: 33f50ffc ("serial: sh-sci: Fix support for hardware-assisted RTS/CTS")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg 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: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

9600 is old school.

Most applications use 115200 as the default baud these days.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Acked-by: NPatrice Chotard <patrice.chotard@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The lock is a sleeping lock and local_irq_save() is not the
standard implementation now. Working for both -RT and non
RT.
Signed-off-by: NLionel Debieve <lionel.debieve@st.com>
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: NPatrice Chotard <patrice.chotard@st.com>
Signed-off-by: NGreg 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: NDenis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: NGreg 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: NJan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Drop comments about tty-driver termios_locked structures, which have
been outdated since commit fe6e29fd ("tty: simplify ktermios
allocation").
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NGreg 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: NJohan Hovold <johan@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The controller has different timings for MMC_TIMING_UHS_DDR50 and
MMC_TIMING_MMC_DDR52. Configuring the controller with SDHCI_CTRL_UHS_DDR50,
when MMC_TIMING_MMC_DDR52 timings are requested, is not correct and can
lead to unexpected behavior.
Signed-off-by: NLudovic Desroches <ludovic.desroches@microchip.com>
Fixes: bb5f8ea4 ("mmc: sdhci-of-at91: introduce driver for the Atmel SDMMC")
Cc: <stable@vger.kernel.org> # 4.4+
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

SDIO cards may need clock to send the card interrupt to the host.

On a cherrytrail tablet with a RTL8723BS wifi chip, without this patch
pinging the tablet results in:

PING 192.168.1.14 (192.168.1.14) 56(84) bytes of data.
64 bytes from 192.168.1.14: icmp_seq=1 ttl=64 time=78.6 ms
64 bytes from 192.168.1.14: icmp_seq=2 ttl=64 time=1760 ms
64 bytes from 192.168.1.14: icmp_seq=3 ttl=64 time=753 ms
64 bytes from 192.168.1.14: icmp_seq=4 ttl=64 time=3.88 ms
64 bytes from 192.168.1.14: icmp_seq=5 ttl=64 time=795 ms
64 bytes from 192.168.1.14: icmp_seq=6 ttl=64 time=1841 ms
64 bytes from 192.168.1.14: icmp_seq=7 ttl=64 time=810 ms
64 bytes from 192.168.1.14: icmp_seq=8 ttl=64 time=1860 ms
64 bytes from 192.168.1.14: icmp_seq=9 ttl=64 time=812 ms
64 bytes from 192.168.1.14: icmp_seq=10 ttl=64 time=48.6 ms

Where as with this patch I get:

PING 192.168.1.14 (192.168.1.14) 56(84) bytes of data.
64 bytes from 192.168.1.14: icmp_seq=1 ttl=64 time=3.96 ms
64 bytes from 192.168.1.14: icmp_seq=2 ttl=64 time=1.97 ms
64 bytes from 192.168.1.14: icmp_seq=3 ttl=64 time=17.2 ms
64 bytes from 192.168.1.14: icmp_seq=4 ttl=64 time=2.46 ms
64 bytes from 192.168.1.14: icmp_seq=5 ttl=64 time=2.83 ms
64 bytes from 192.168.1.14: icmp_seq=6 ttl=64 time=1.40 ms
64 bytes from 192.168.1.14: icmp_seq=7 ttl=64 time=2.10 ms
64 bytes from 192.168.1.14: icmp_seq=8 ttl=64 time=1.40 ms
64 bytes from 192.168.1.14: icmp_seq=9 ttl=64 time=2.04 ms
64 bytes from 192.168.1.14: icmp_seq=10 ttl=64 time=1.40 ms

Cc: Dong Aisheng <b29396@freescale.com>
Cc: Ian W MORRISON <ianwmorrison@gmail.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NDong Aisheng <aisheng.dong@nxp.com>
Cc: stable@vger.kernel.org
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

Without this, the first modeset would dereference past the allocation
when trying to free the mm node.
Signed-off-by: NEric Anholt <eric@anholt.net>
Tested-by: NStefan Wahren <stefan.wahren@i2se.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170328201343.4884-1-eric@anholt.net
Fixes: d8dbf44f ("drm/vc4: Make the CRTCs cooperate on allocating display lists.")
Cc: <stable@vger.kernel.org> # v4.6+
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>