The device has a highspeed register which influences the calcualtion
of the divisor. The chip lacks support for some baudrates. When requested,
we set the divisor to the next smaller baudrate and adjust the c_cflag
accordingly.
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit: e676253b [3/21] serial/8250: Add
support for RS485 IOCTLs, adds a building error on arch m32r.

All error/warnings:

   drivers/tty/serial/8250/8250_core.c: In function 'serial8250_ioctl':
>> drivers/tty/serial/8250/8250_core.c:2859:3: error: implicit declaration of function 'copy_from_user' [-Werror=implicit-function-declaration]
      if (copy_from_user(&rs485_config, (void __user *)arg,
      ^
>> drivers/tty/serial/8250/8250_core.c:2871:3: error: implicit declaration of function 'copy_to_user' [-Werror=implicit-function-declaration]
      if (copy_to_user((void __user *)arg, &up->rs485,
      ^
   cc1: some warnings being treated as errors
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The OMAP version of the 8250 can actually use 1:1 serial8250_startup().
However it needs to be extended by a wake up irq which should to be
requested & enabled at ->startup() time and disabled at ->shutdown() time.

v2…v3: properly copy callbacks
v1…v2: add shutdown callback
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no way to access a struct uart_8250_port for a specific
line. This is only required outside of the 8250/uart callbacks like for
devices' suspend & remove callbacks. For those the 8250-core provides a
wrapper like serial8250_unregister_port() which passes the struct
to the proper function based on the line argument.

For run time suspend I need access to this struct not only to make
serial_out() work but also to properly restore up->ier and up->mcr.
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Existing callers of serial8250_modem_status() [1] hold the uart port
lock; document.

[1] In-tree callers of serial8250_modem_status()

drivers/tty/serial/8250/8250_fsl.c
  fsl8250_handle_irq()

drivers/tty/serial/8250/8250_core.c
  serial8250_handle_irq()
  serial8250_console_write()
  serial8250_get_mctrl() *

* Call graphs for callers of serial8250_get_mctrl() from the function
  which acquires the uart port lock

drivers/tty/serial/serial_core.c
  uart_port_startup()
  uart_tiocmget()
  uart_set_termios()
  uart_carrier_raised()
    ops->get_mctrl() ---> serial8250_get_mctrl()
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 06aa82e4.
This commit purports to enable auto CTS flow control for the 8250
UART driver. However, the 8250 UART driver already supports auto
CTS flow control via UART_CAP_AFE and UART_CAP_EFR. Indeed, this
patch introduces another DT attribute for which an existing firmware
flag already exists ("auto-flow-control"). Furthermore, the use of
UPF_HARD_FLOW requires the UART driver to define .throttle and
.unthrottle methods, neither of which are defined for the 8250 UART
driver (which will result in a NULL ptr dereference). Finally, this patch
supposes to fix existing bugs in the serial core for auto CTS-enabled
hardware, but does not include the class of hardware for which these
bugs exist.

CC: Murali Karicheri <m-karicheri2@ti.com>
CC: Rob Herring <robh+dt@kernel.org>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The symbol is defined in drivers/tty/serial/8250/Kconfig as
"SERIAL_8250", not just "8250".
Signed-off-by: NDaniele Forsi <dforsi@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch lets you set the RS485 cappabilites of the device through
TIOCSRS485 and TIOCGRS485 as defined on Documentation/serial/serial-rs485.txt

In order to probe the device, the PNP id and the device id is used.
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch allow the users of the 8250 infrastructure to define a
handler for RS485 configration.

If no handler is defined the 8250 driver will work as usual.
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: NAlan Cox <alan@linux.intel.com>
--
v2:Change suggested by Alan "One Thousand Gnomes":
- Move rs485 structure further down on the uart_8250_port structure

 drivers/tty/serial/8250/8250_core.c | 39 +++++++++++++++++++++++++++++++++++++
 include/linux/serial_8250.h         |  3 +++
 2 files changed, 42 insertions(+)
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The 8250_dw driver fails to probe if the specified clock isn't
registered at probe time. Even if a clock frequency is given,
the required clock might be gated because it wasn't properly
enabled.

This happened to me when the device is registered through DT,
and the clock was part of an MFD, the PRCM found on A31 and A23
SoCs. Unlike core clocks that are registered with OF_CLK_DECLARE,
which happen almost immediately after the kernel starts, the
clocks are registered as sub-devices of the PRCM MFD platform
device. Even though devices are registered in the order they are
found in the DT, the drivers are registered in a different,
arbitrary order. It is possible that the 8250_dw driver is
registered, and thus associated with the device and probed, before
the clock driver is registered and probed.

8250_dw then reports unable to get the clock, and fails. Without
a working console, the kernel panics.

This patch adds support for deferred probe handling for the clock
and reset controller. It also fixes the cleanup path if
serial8250_register_8250_port fails.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Allwinner A31 and A23 SoCs have a reset controller
maintaining the UART in reset by default.

This patch adds optional reset support to the driver.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Acked-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add tunable RX interrupt trigger I/F of FIFO buffers.

Serial devices are used as not only message communication devices but control
or sending communication devices. For the latter uses, normally small data
will be exchanged, so user applications want to receive data unit as soon as
possible for real-time tendency. If we have a sensor which sends a 1 byte data
each time and must control a device based on the sensor feedback, the RX
interrupt should be triggered for each data.

According to HW specification of serial UART devices, RX interrupt trigger
can be changed, but the trigger is hard-coded. For example, RX interrupt trigger
in 16550A can be set to 1, 4, 8, or 14 bytes for HW, but current driver sets
the trigger to only 8bytes.

This patch makes some devices change RX interrupt trigger from userland.

<How to use>
- Read current setting
 # cat /sys/class/tty/ttyS0/rx_trig_bytes
 8

- Write user setting
 # echo 1 > /sys/class/tty/ttyS0/rx_trig_bytes
 # cat /sys/class/tty/ttyS0/rx_trig_bytes
 1

<Support uart devices>
- 16550A and Tegra (1, 4, 8, or 14 bytes)
- 16650V2 (8, 16, 24, or 28 bytes)
- 16654 (8, 16, 56, or 60 bytes)
- 16750 (1, 16, 32, or 56 bytes)

<Change log>
Changes in V9:
 - Use attr_group instead of dev_spec_attr_group of uart_port structure

Changes in V8:
 - Divide this patch from V7's patch based on Greg's comment

Changes in V7:
 - Add Documentation
 - Change I/F name from rx_int_trig to rx_trig_bytes because the name
   rx_int_trig is hard to understand how users specify the value

Changes in V6:
 - Move FCR_RX_TRIG_* definition in 8250.h to include/uapi/linux/serial_reg.h,
   rename those to UART_FCR_R_TRIG_*, and use UART_FCR_TRIGGER_MASK to
   UART_FCR_R_TRIG_BITS()
 - Change following function names:
    convert_fcr2val() => fcr_get_rxtrig_bytes()
    convert_val2rxtrig() => bytes_to_fcr_rxtrig()
 - Fix typo in serial8250_do_set_termios()
 - Delete the verbose error message pr_info() in bytes_to_fcr_rxtrig()
 - Rename *rx_int_trig/rx_trig* to *rxtrig* for several functions or variables
   (but UI remains rx_int_trig)
 - Change the meaningless variable name 'val' to 'bytes' following functions:
    fcr_get_rxtrig_bytes(), bytes_to_fcr_rxtrig(), do_set_rxtrig(),
    do_serial8250_set_rxtrig(), and serial8250_set_attr_rxtrig()
 - Use up->fcr in order to get rxtrig_bytes instead of rx_trig_raw in
   fcr_get_rxtrig_bytes()
 - Use conf_type->rxtrig_bytes[0] instead of switch statement for support check
   in register_dev_spec_attr_grp()
 - Delete the checking whether a user changed FCR or not when minimum buffer
   is needed in serial8250_do_set_termios()

Changes in V5.1:
 - Fix FCR_RX_TRIG_MAX_STATE definition

Changes in V5:
 - Support Tegra, 16650V2, 16654, and 16750
 - Store default FCR value to up->fcr when the port is first created
 - Add rx_trig_byte[] in uart_config[] for each device and use rx_trig_byte[]
   in convert_fcr2val() and convert_val2rxtrig()

Changes in V4:
 - Introduce fifo_bug flag in uart_8250_port structure
   This is enabled only when parity is enabled and UART_BUG_PARITY is enabled
   for up->bugs. If this flag is enabled, user cannot set RX trigger.
 - Return -EOPNOTSUPP when it does not support device at convert_fcr2val() and
   at convert_val2rxtrig()
 - Set the nearest lower RX trigger when users input a meaningless value at
   convert_val2rxtrig()
 - Check whether p->fcr is existing at serial8250_clear_and_reinit_fifos()
 - Set fcr = up->fcr in the begging of serial8250_do_set_termios()

Changes in V3:
 - Change I/F from ioctl(2) to sysfs(rx_int_trig)

Changed in V2:
 - Use _IOW for TIOCSFIFORTRIG definition
 - Pass the interrupt trigger value itself
Signed-off-by: NYoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It helps to cast struct uart_port to struct uart_8250_port at runtime.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

First try to find the named clock variants then fall back to the already
existing handling of a nameless declared baudclk.

This also adds the missing documentation for this already existing variant.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The flags member has upf_t type and corresponding macros to define them. This
patch converts ASYNC_SKIP_TEST to UPF_SKIP_TEST in 8250_dw.c.

Otherwise we got a sparse warning:
drivers/tty/serial/8250/8250_dw.c:302:46: warning: restricted upf_t degrades to integer
drivers/tty/serial/8250/8250_dw.c:302:62: warning: restricted upf_t degrades to integer
drivers/tty/serial/8250/8250_dw.c:302:26: warning: incorrect type in assignment (different base types)
drivers/tty/serial/8250/8250_dw.c:302:26:    expected restricted upf_t [usertype] flags
drivers/tty/serial/8250/8250_dw.c:302:26:    got unsigned int
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This replaces the Baytrail specific custom set_termios hook
with a more generic one where the clock framework is used to
set the rate. The method also doesn't need to be limited to
just Baytrail, so it's used with all ACPI platforms.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In the conversion to generic early console, the passing of options from
the early 8250 console to the regular ttyS console was broken. This
resulted in the baud rate changing when switching consoles during boot.

This feature allows specifying a single console option on the kernel
command line rather than both an early console and regular serial tty
console. It would be nice to generalize this feature. However, it only
works if the correct baud rate can be probed early which is not the
case on many platforms which have non-standard UART clock rates. So for
now, this is left as an 8250 specific feature.
Reported-and-tested-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NRob Herring <robh@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If IGNBRK is set without either BRKINT or PARMRK set, some uart
drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the
line discipline, when it should send either nothing or the TTYBREAK flag
set. This happens because the read_status_mask masks out the BI
condition, which uart_insert_char() then interprets as a normal 0x00 byte.

SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General
Terminal Interface - Input Modes, states:
  "If IGNBRK is set, a break condition detected on input shall be ignored;
   that is, not put on the input queue and therefore not read by any
   process."

Fix read_status_mask to include the BI bit if IGNBRK is set; the
lsr status retains the BI bit if a BREAK is recv'd, which is
subsequently ignored in uart_insert_char() when masked with the
ignore_status_mask.

Affected drivers:
8250 - all
serial_txx9
mfd
amba-pl010
amba-pl011
atmel_serial
bfin_uart
dz
ip22zilog
max310x
mxs-auart
netx-serial
pnx8xxx_uart
pxa
sb1250-duart
sccnxp
serial_ks8695
sirfsoc_uart
st-asc
vr41xx_siu
zs
sunzilog
fsl_lpuart
sunsab
ucc_uart
bcm63xx_uart
sunsu
efm32-uart
pmac_zilog
mpsc
msm_serial
m32r_sio

Unaffected drivers:
omap-serial
rp2
sa1100
imx
icom

Annotated for fixes:
altera_uart
mcf

Drivers without break detection:
21285
xilinx-uartps
altera_jtaguart
apbuart
arc-uart
clps711x
max3100
uartlite
msm_serial_hs
nwpserial
lantiq
vt8500_serial

Unknown:
samsung
mpc52xx_uart
bfin_sport_uart
cpm_uart/core

Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag'
Reported-by: NIvan <athlon_@mail.ru>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Using dma_mapping_error() to make sure the mapping did not
fail.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

8250 uart driver currently supports only software assisted hw flow
control. The software assisted hw flow control maintains a hw_stopped
flag in the tty structure to stop and start transmission and use modem
status interrupt for the event to drive the handshake signals. This is
not needed if hw has flow control capabilities. This patch adds a
DT attribute for enabling hw flow control for a uart port. Also skip
stop and start if this flag is present in flag field of the port
structure.
Signed-off-by: NMurali Karicheri <m-karicheri2@ti.com>
CC: Rob Herring <robh+dt@kernel.org>
CC: Pawel Moll <pawel.moll@arm.com>
CC: Mark Rutland <mark.rutland@arm.com>
CC: Ian Campbell <ijc+devicetree@hellion.org.uk>
CC: Kumar Gala <galak@codeaurora.org>
CC: Randy Dunlap <rdunlap@infradead.org>
CC: Jiri Slaby <jslaby@suse.cz>
CC: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add support for Advantech PCM-3614I/PCM-3618I serial expansion cards

Advantech makes a variety of serial port expansion cards, including the
PCM-3614 and PCM-3618
(http://www.advantech.com/products/1-2JKLU5/PCM-3618/mod_5DF8DE5A-6B49-4429-BB2F-CB35FE1D168D.aspx).
They have a driver available which was forked from the kernel driver
ages ago and has not been maintained in quite some time, available at
http://support.advantech.com.tw/Support/DownloadSRDetail_New.aspx?SR_ID=1-1W8FZ5&Doc_Source=Download
Their driver added several features to aid in communications at higher
baud rates, but at normal serial port speeds, the standard 8250_pci
driver functions just fine. This patch adds the necessary PCI IDs to
recognize this card.

See bug 75681 (https://bugzilla.kernel.org/show_bug.cgi?id=75681)
Signed-off-by: NThomee Wright <TWright@TMCDesign.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This Multi-IO card has one serial 16550-like and one parallel port connector.
Here's the lspci output, after this commit is applied:

03:07.0 Serial controller: Device 4348:5053 (rev 10) (prog-if 02 [16550])
	Subsystem: Device 4348:5053
	Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
	Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Interrupt: pin A routed to IRQ 21
	Region 0: I/O ports at cf00 [size=8]
	Region 1: I/O ports at ce00 [size=8]
	Kernel driver in use: parport_serial
	Kernel modules: 8250_pci, parport_serial

This commit adds an entry with the device ID to the blacklist declared in
8250_pci to prevent the driver from taking ownership. Also, and as was done
for the 2S/1P variant, add a quirk to skip autodetection and set the correct
type to 16550A clone.

Proper entries are added to parport_serial, to support the device parallel
and serial ports.

Cc: Gianluca Anzolin <gianluca@sottospazio.it>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit d2fd6810 (tty/serial: convert 8250 to generic earlycon)
removed setup_early_serial8250_console, but there are still 2 callers
in:

arch/mips/mti-malta/malta-init.c
drivers/firmware/pcdp.c

Add back the function implemented as a wrapper to setup_earlycon.
Reported-by: NYinghai Lu <yinghai@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The sleep function was updated to put the serial port to sleep only when necessary.
This appears to resolve the errant behavior of the driver as described in
Kernel Bug 61961 – "My Exar Corp. XR17C/D152 Dual PCI UART modem does not
work with 3.8.0".
Signed-off-by: NMichael Welling <mwelling@ieee.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With the generic earlycon infrastructure in place, convert the 8250
early console to use it.
Signed-off-by: NRob Herring <robh@kernel.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In preparation to support FIX_EARLYCON_MEM on other arches, make the
option per arch.
Signed-off-by: NRob Herring <robh@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In (efe2f29e kgdboc,kdb: Allow kdb to work on a non open console port)
support was added to directly use the "write_char" functions when
doing kdb over a non-open console port.  This is great, but it ends up
bypassing the normal code in uart_console_write() that adds a carriage
return before any newlines.

There appears to have been a trend to add this support directly in
some console driver's poll_put_char() functions.  This had a few side
effects, including:
- In this case we were doing LFCR, not CRLF.  This was fixed in
  uart_console_write() back in (d358788f [SERIAL] kernel console should
  send CRLF not LFCR)
- Not all serial drivers had the LFCR code in their poll_put_char()
  functions.  In my case I was running serial/samsung.c which lacked
  it.

I've moved the handling to uart_poll_put_char() to fix the above
problems.  Now when I use kdb (and don't point console= to the same
UART) I no longer get:

[0]kdb>
       [0]kdb>
              [0]kdb>
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Reviewed-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In the same manner as 8250_pci, 8250_dw needs some
baytrail specific quirks to be used. The reference
clock needs to be adjusted before divided in order
to have the minimum error rate on the baudrate.

The specific byt set termios function is stored in
the driver_data field of the acpi device id via the
dw8250_acpi_desc structure.

Remove the uartclk field which is no longer delivered
as driver data.
Signed-off-by: NLoic Poulain <loic.poulain@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

__dma_tx_complete is not protected against concurrent
call of serial8250_tx_dma. it can lead to circular tail
index corruption or parallel call of serial_tx_dma on the
same data portion.

This patch fixes this issue by holding the port lock.
Signed-off-by: NLoic Poulain <loic.poulain@intel.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On transmit-hold-register empty, serial8250_tx_chars
should be called only if we don't use DMA.
DMA has its own tx cycle.
Signed-off-by: NLoic Poulain <loic.poulain@intel.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit f4f653e9.

Jiri writes:
	No, please drop this one. We need a better solution as it turned
	out that some boxes need 16k loops and it will increase with new
	processors :(.

Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Martin Pluskal <mpluskal@suse.com>
Cc: Takashi Iwai <tiwai@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The 8250 driver now reports many of these:
  serial8250: too much work for irq4
These messages turned out to be common these days with a use of
virtualization. I tried to increase the limit of processed characters
in commit e7328ae1 (serial: 8250,
increase PASS_LIMIT) in 2011. It was raised from 256 to 512, but it is
still not enough, apparently.

So disable the warning unless somebody turns on DEBUG (or
DYNAMIC_DEBUG _and_ the message).
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Reported-by: NMartin Pluskal <mpluskal@suse.com>
Reported-by: NTakashi Iwai <tiwai@suse.com>
Tested-by: NTakashi Iwai <tiwai@suse.de>
References: https://bugzilla.novell.com/show_bug.cgi?id=868394Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In -RT the spin_lock_irqsave() does not spin but sleep if the lock is
taken. Before that, local_irq_save() is invoked which disables
interrupts even on -RT. Therefore local_irq_save() + spin_lock() does not
work.
In the ->sysrq and oops_in_progress case it is save to trylock the lock
i.e. this is what we do now anyway except for ->sysrq where we assume
that the lock is already taken.

The spin_lock_irqsave() grabs the lock and disables the interrupts on
vanilla (the same behavior) and on -RT it won't disable interrupts.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
[bigeasy: add a patch description]
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Intel BayTrail HSUART power-on default reference clock is 44.2368 MHz,
but 73.728 MHz provides 0% error for additional "conventional" baud rates
above 460800 (e.g. 576000, 921600, and 1152000).
Signed-off-by: NAaron Sierra <asierra@xes-inc.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Support the following additional baud rates with 0% error:
	500000, 1500000, 2500000, 3500000
Signed-off-by: NAaron Sierra <asierra@xes-inc.com>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Every couple of months, someone sends a patch to fix:

drivers/tty/serial/8250/8250_core.c: In function 'serial_unlink_irq_chain':
drivers/tty/serial/8250/8250_core.c:1712:2: warning: 'i' may be used uninitialized in this function [-Wuninitialized]

and they in turn get a NACK for their efforts, and are told that
their compiler is broken.  This has been going on since at least
the year 2008:  https://lkml.org/lkml/2008/11/24/433

Lets add a comment, so that subsequent patches don't get as far as
the maintainers or the mailing lists.
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Exar XR17V35x family of UARTs have an additional fractional divisor
register (DLD) which was not being used. Calculate and set this
register for these devices to reduce their baud rate error.
Signed-off-by: NJoe Schultz <jschultz@xes-inc.com>
Signed-off-by: NAaron Sierra <asierra@xes-inc.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Aparently 9865 uses standard BAR encoding scheme (unlike 99xx cards).
Current pci_netmos_9900_setup() uses wrong BAR indices for the 9865 PCI
device, function 2. Using standard BAR indices makes all 6 ports work
for me. Thus disable the NetMos 9900 quirk for NetMos 9865 pci device.

For the reference, here is the relevant part of lspci for my device:

02:07.0 Serial controller: MosChip Semiconductor Technology Ltd. PCI
9865 Multi-I/O Controller (prog-if 02 [16550])
	Subsystem: Device a000:1000
	Flags: bus master, medium devsel, latency 32, IRQ 17
	I/O ports at ac00 [size=8]
	Memory at fcfff000 (32-bit, non-prefetchable) [size=4K]
	Memory at fcffe000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [48] Power Management version 2
	Kernel driver in use: serial

02:07.1 Serial controller: MosChip Semiconductor Technology Ltd. PCI
9865 Multi-I/O Controller (prog-if 02 [16550])
	Subsystem: Device a000:1000
	Flags: bus master, medium devsel, latency 32, IRQ 18
	I/O ports at a800 [size=8]
	Memory at fcffd000 (32-bit, non-prefetchable) [size=4K]
	Memory at fcffc000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [48] Power Management version 2
	Kernel driver in use: serial

02:07.2 Communication controller: MosChip Semiconductor Technology Ltd.
PCI 9865 Multi-I/O Controller
	Subsystem: Device a000:3004
	Flags: bus master, medium devsel, latency 32, IRQ 19
	I/O ports at a400 [size=8]
	I/O ports at a000 [size=8]
	I/O ports at 9c00 [size=8]
	I/O ports at 9800 [size=8]
	Memory at fcffb000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [48] Power Management version 2
	Kernel driver in use: serial
Signed-off-by: NDmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_PM will be set if either or both CONFIG_PM_SLEEP and
CONFIG_PM_RUNTIME is set. Compiling the driver with !CONFIG_PM_SLEEP causes
following compilation warnings:

drivers/tty/serial/8250/8250_dw.c:404:12: warning: ‘dw8250_suspend’ defined but not used [-Wunused-function]
drivers/tty/serial/8250/8250_dw.c:413:12: warning: ‘dw8250_resume’ defined but not used [-Wunused-function]

Fix this by using CONFIG_PM_SLEEP instead.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Tegra chips have 4 or 5 identical UART modules embedded. UARTs C..E have
their MODEM-control signals tied off to a static state. However UARTs A
and B can optionally route those signals to/from package pins, depending
on the exact pinmux configuration.

When these signals are not routed to package pins, false interrupts may
trigger either temporarily, or permanently, all while not showing up in
the IIR; it will read as NO_INT. This will eventually lead to the UART
IRQ being disabled due to unhandled interrupts. When this happens, the
kernel may print e.g.:

    irq 68: nobody cared (try booting with the "irqpoll" option)

In order to prevent this, enable UART_BUG_NOMSR. This prevents
UART_IER_MSI from being enabled, which prevents the false interrupts
from triggering.

In practice, this is not needed under any of the following conditions:

* On Tegra chips after Tegra30, since the HW bug has apparently been
  fixed.

* On UARTs C..E since their MODEM control signals are tied to the correct
  static state which doesn't trigger the issue.

* On UARTs A..B if the MODEM control signals are routed out to package
  pins, since they will then carry valid signals.

However, we ignore these exceptions for now, since they are only relevant
if a board actually hooks up more than a 4-wire UART, and no currently
supported board does this. If we ever support a board that does, we can
refine the algorithm that enables UART_BUG_NOMSR to take those exceptions
into account, and/or read a flag from DT/... that indicates that the
board has hooked up and pinmux'd more than a 4-wire UART.

Reported-by: Olof Johansson <olof@lixom.net> # autotester
Cc: <stable@vger.kernel.org>
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>