The tty lock is held when the tty driver's hangup() method is called
(from the lone call-site, __tty_hangup()). The call-tree audit [1]
of tty_port_hangup() is a closed graph of the callers of
tty_port_hangup(); ie., all callers originate only from __tty_hangup().

Of these callers, none drop the tty lock prior to calling
tty_port_hangup().

[1]
Call-tree audit of tty_port_hangup()

__tty_hangup()
  tty->ops->hangup() --+
                       |
        rs_hangup():arch/ia64/hp/sim/simserial.c
        line_hangup():arch/um/drivers/line.c
        gdm_tty_hangup():drivers/staging/gdm724x/gdm_tty.c
        fwtty_hangup():drivers/staging/fwserial/fwserial.c
        acm_tty_hangup():drivers/usb/class/cdc-acm.c
        serial_hangup():drivers/usb/serial/usb-serial.c
        ipoctal_hangup():drivers/ipack/devices/ipoctal.c
        cy_hangup():drivers/tty/cyclades.c
        isicom_hangup():drivers/tty/isicom.c
        rp_hangup():drivers/tty/rocket.c
        dashtty_hangup():drivers/tty/metag_da.c
        moxa_hangup():drivers/tty/moxa.c
        gsmtty_hangup():drivers/tty/n_gsm.c
        goldfish_tty_hangup():drivers/tty/goldfish.c
        ehv_bc_tty_hangup():drivers/tty/ehv_bytechan.c
        mxser_hangup():drivers/tty/mxser.c
        kgdb_nmi_tty_hangup():drivers/tty/serial/kgdb_nmi.c
        ifx_spi_hangup():drivers/tty/serial/ifx6x60.c
        ntty_hangup():drivers/tty/nozomi.c
        capinc_tty_hangup():drivers/isdn/capi/capi.c
        mgslpc_hangup():drivers/char/pcmcia/synclink_cs.c
        sdio_uart_hangup():drivers/mmc/card/sdio_uart.c
        rfcomm_tty_hangup():net/bluetooth/rfcomm/tty.c
                       |
                       +- tty_port_hangup()
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The tty lock is held when the tty driver's open() method is called
(from tty_open()). The call-tree audit [1] of tty_port_block_til_ready()
is a closed graph of the callers of tty_port_block_til_ready();
ie., all callers originate only from tty_open().

Of these callers, none drop the tty lock.

Also, document tty_port_block_til_ready() may drop and reacquire
the tty lock when blocking, which means the tty or tty_port may have
changed state.

[1]
Call-tree audit of tty_port_block_til_ready()
* does not include call tree of tty_port_open() which is already
  documented in 'tty: Document locking from tty_port_open()'

tty_open()
  tty->ops->open() --+
                     |
        cy_open():drivers/tty/cyclades.c
        rp_open():drivers/tty/rocket.c
        rs_open():drivers/tty/amiserial.c
        moxa_open():drivers/tty/moxa.c
        gsmtty_open():drivers/tty/n_gsm.c
        rs_open():drivers/tty/serial/68328serial.c
        uart_open():drivers/tty/serial/serial_core.c
        isdn_tty_open():drivers/isdn/i4l/isdn_tty.c
        mgslpc_open():drivers/char/pcmcia/synclink_cs.c
                     |
                     +- tty_port_block_til_ready()
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The tty lock is held when the tty driver's open method is called
(from the lone call-site, tty_open()). The call-tree audit [1] of
tty_port_open() is a closed graph of the callers of tty_port_open();
ie., all callers originate from only tty_open().

Of these callers, none drop the tty lock.

Also, document that tty_port_block_til_ready() may drop and reacquire
the tty lock when blocking, which means the tty or tty_port may have
changed state.

[1]
Call-tree audit of tty_port_open()

tty_open()
  tty->ops->open() --+
                     |
        rs_open():arch/ia64/hp/sim/simserial.c
       *line_open():arch/um/drivers/line.c
        gdm_tty_open():drivers/staging/gdm724x/gdm_tty.c
        fwtty_open():drivers/staging/fwserial/fwserial.c
        acm_tty_open():drivers/usb/class/cdc-acm.c
        serial_open():drivers/usb/serial/usb-serial.c
        pti_tty_driver_open():drivers/misc/pti.c
        ipoctal_open():drivers/ipack/devices/ipoctal.c
        isicom_open():drivers/tty/isicom.c
        dashtty_open():drivers/tty/metag_da.c
        goldfish_tty_open():drivers/tty/goldfish.c
        ehv_bc_tty_open():drivers/tty/ehv_bytechan.c
        mxser_open():drivers/tty/mxser.c
        kgdb_nmi_tty_open():drivers/tty/serial/kgdb_nmi.c
        ifx_spi_open():drivers/tty/serial/ifx6x60.c
        smd_tty_open():drivers/tty/serial/msm_smd_tty.c
        ntty_open():drivers/tty/nozomi.c
        capinc_tty_open():drivers/isdn/capi/capi.c
        tpk_open():drivers/char/ttyprintk.c
        sdio_uart_open():drivers/mmc/card/sdio_uart.c
        rfcomm_tty_open():net/bluetooth/rfcomm/tty.c
                     |
                     +- tty_port_open()

* line_open() is the .open method for 2 um drivers
  declared in ./arch/um/drivers/stdio_console.c and
  in ./arch/um/drivers/ssl.c, and not called directly
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The tty lock is held when the tty driver's .close method is called
(from the two lone call-sites of tty_release() and __tty_hangup()).
The call-tree audit[1] of tty_port_close(), tty_port_close_start,
and tty_port_close_end() is a closed graph of the callers of these
3 functions; ie., all callers originate from only tty_release()
or __tty_hangup().

Of these callers, none drop the tty lock.

Also, document tty_port_close_start() may drop and reacquire the
tty lock in tty_wait_until_sent_from_close(), which means the tty
or tty_port may have changed state (but not reopened or hung up).

[1]
Call-tree audit of tty_port_close, tty_port_close_start, and tty_port_close_end()

tty_release()
  tty->ops->close() --+
                      |
__tty_hangup()        |
  tty->ops->close() --+
                      |
                      +- rp_close():drivers/tty/rocket.c -------------------+
                      +- uart_close():drivers/tty/serial/serial_core.c -----+
                      |                                                     +- tty_port_close_start()
                      |
                      |
                      +- close():drivers/tty/synclinkmp.c ------------------+
                      +- rs_close():drivers/tty/amiserial.c ----------------+
                      +- gsmtty_close():drivers/tty/n_gsm.c ----------------+
                      +- mxser_close():drivers/tty/mxser.c -----------------+
                      +- close():drivers/tty/synclink_gt.c -----------------+
                      +- mgsl_close():drivers/tty/synclink.c ---------------+
                      +- isdn_tty_close():drivers/isdn/i4l/isdn_tty.c ------+
                      +- mgslpc_close():drivers/char/pcmcia/synclink_cs.c --+
                      +- ircomm_tty_close():net/irda/ircomm/ircomm_tty.c ---+
                      |                                                     |
        rs_close():arch/ia64/hp/sim/simserial.c                             |
       *line_close():arch/um/drivers/line.c                                 |
        gdm_tty_close():drivers/staging/gdm724x/gdm_tty.c
        fwtty_close():drivers/staging/fwserial/fwserial.c
        acm_tty_close():drivers/usb/class/cdc-acm.c
        serial_close():drivers/usb/serial/usb-serial.c
        pti_tty_driver_close():drivers/misc/pti.c
        ipoctal_close():drivers/ipack/devices/ipoctal.c
        cy_close():drivers/tty/cyclades.c
        isicom_close():drivers/tty/isicom.c
        dashtty_close():drivers/tty/metag_da.c
        moxa_close():drivers/tty/moxa.c
        goldfish_tty_close():drivers/tty/goldfish.c
        ehv_bc_tty_close():drivers/tty/ehv_bytechan.c
        kgdb_nmi_tty_close():drivers/tty/serial/kgdb_nmi.c
        ifx_spi_close():drivers/tty/serial/ifx6x60.c
        smd_tty_close():drivers/tty/serial/msm_smd_tty.c
        ntty_close():drivers/tty/nozomi.c
        capinc_tty_close():drivers/isdn/capi/capi.c
        tpk_close():drivers/char/ttyprintk.c
        sdio_uart_close():drivers/mmc/card/sdio_uart.c                      |
        rfcomm_tty_close():net/bluetooth/rfcomm/tty.c                       |
                      |                                                     |
                      +- tty_port_close():drivers/tty/tty_port.c -----------+
                                                                            |
                                                                            +- tty_port_close_start()
                                                                            +- tty_port_close_end()

* line_close() is the .close method for 2 um drivers,
  declared in ./arch/um/drivers/stdio_console.c and
  in ./arch/um/drivers/ssl.c, and not called directly
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The tty core calls the tty driver's open, close and hangup
methods holding the tty lock.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The DMA burst size must match the transmit FIFO depth in order
to make sure all character are transmitted. This patch calculates
DMA burst size by using FIFO depth rather than use the hardcoded
16 bytes. This is required since some UARTs (e.g. UART2 on Vybrid)
have a FIFO depth of 8 bytes.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The DMA RX timeout calculation is done based on FIFO buffer size and
port timeout when setting up DMA. However, both variables are not
necessarily initialized at DMA initialization time, which can lead
to a division by zero.

Move the timeout calculation to set_termios where both variables
are initialized.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When a tty is opened for the serial console, the termios c_cflag
settings are inherited from the console line settings.
However, if the tty is subsequently closed, the termios settings
are lost. This results in a garbled console if the console is later
suspended and resumed.

Preserve the termios c_cflag for the serial console when the tty
is shutdown; this reflects the most recent line settings.

Fixes: Bugzilla #69751, 'serial console does not wake from S3'
Reported-by: NValerio Vanni <valerio.vanni@inwind.it>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Rx dma descriptor allocated without the DMA_ACK flags so that
once after tarnsfer done or terminated, client can ack the descriptor
to free it for later use.

If the Rx DMA is terminated for some reason then rx-dma descriptor
is not getting acked which causes the memory leak and list of usage
desc to grow continuously.

Hence, acknowledge the rx-dma descriptor once transfer is terminated
to avoid memory leak and desc list to grow.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When channel is require to stop transmit then update the Tx circular
buffer only when DMA based transfer is in progress. If there is no
DMA based transfer then no need to update the Tx buffer.
Signed-off-by: NPradeep Goudagunta <pgoudagunta@nvidia.com>
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Every uart driver that provides a console driver needs to
be built-in for the console code to work, we get a build
error for modular console drivers.

This changes the SERIAL_HS_LPC32XX_CONSOLE symbol to depend
on the SERIAL_HS_LPC32XX driver being built-in, just like
we do for all the other uart drivers.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When CONFIG_SERIAL_PXA_CONSOLE is disabled, the serial_pxa_get_poll_char
and serial_pxa_put_poll_char functions are not defined, and we can't
reference them.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With recent improvements to serial/of core from Grant and Rob,
stdout-path alone suffices for setting up earlycon/console.

arc_uart driver is already equipped to handle that, switch the DT now.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This allows a param less earlycon to pick up the earlyconsole from
chosen/stdout-path
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With ARC uart driver switching to generic earlycon, we no longer need
this ugliness. You won't be missed.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With this change both earlyprintk and earlycon coexist
We switch over to latter in next patch
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The ARC UART MMIO helpers would take arc_uart_port and then reference
generic uart_port->membase member. So change them to difrectly refer to
uart_port and fix call sites accordingly.

This removes the need for to_arc_port() converion almost eveeywhere and
makes code a bit easier to read.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Reviewed-by: NRob Herring <robh@kernel.org>
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>

When building multi_v7_defconfig with CONFIG_ARM_LPAE=y the following warning
is seen:

drivers/tty/serial/samsung.c: In function 's3c24xx_serial_init_port':
drivers/tty/serial/samsung.c:1229:2: warning: format '%x' expects argument of type 'unsigned int', but argument 2 has type 'resource_size_t' [-Wformat]

Use %pa to print 'resource_size_t' type to fix the warning.
Reported-by: NOlof's autobuilder <build@lixom.net>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Reviewed-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is a risk that the variable will be used without being initialized.

This was largely found by using a static code analysis program called cppcheck.
Signed-off-by: NRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

the current codes send 1 bytes, then after getting TX done interrupt,
send subsequent bytes. it causes redundant interrupts.
for example, if we have 3 bytes in TX buffer, the TX flow is:
1. send 1 byte
2. get TX down interrupt
3. send the left 2 bytes
4. get TX down interrupt

this patch moves to send more bytes and decrease interrupts, the new
flow is:
1. send 3 bytes
2. get TX down interrupt
Signed-off-by: NQipan Li <Qipan.Li@csr.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Call uart_write_wakeup() after writing the hardware FIFO and updateing the FIFO
pointers.

This fixes high latency and jitter on PPP over Serial links.
Reported-by: NJun Shih <Jun.Shih@pason.com>
Tested-by: NJun Shih <Jun.Shih@pason.com>
Signed-off-by: NJohannes Thumshirn <johannes.thumshirn@men.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch makes enable_ms() optional, so we can eliminate a lot of
empty enable_ms() implementations from driver code.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch removes s5pc100 related serial.
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch removes s5p64x0 related serial because of removing
support for s5p64x0 SoCs.
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds alias entries for UART nodes of all SoCs using
samsung-uart compatible UART controllers, so that the dependency on
probe order is removed and deterministic device naming is assured.
Signed-off-by: NTomasz Figa <t.figa@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Current driver code relies on probe order of particular samsung-uart
instances, which makes it impossible to get proper initialization of
ports when not all ports are available on board, not even saying of
deterministic device naming.

This patch fixes this on DT-enabled systems by using DT aliases for
ports as instance ID, if specified, or falling back to legacy method
otherwise to provide backwards compatibility.
Signed-off-by: NTomasz Figa <t.figa@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The primary purpose of this patch is to add information about (now
required) aliases of UART ports. However the documentation currently is
heavily outdated and so this patch also takes care of this.
Signed-off-by: NTomasz Figa <t.figa@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Migrating to use devres managed APIs devm_kzalloc, devm_ioremap and
devm_clk_get.
Signed-off-by: NTushar Behera <tushar.b@samsung.com>
Reviewed-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The label 'out' is only used to return the error code. We can return the
error code directly and remove 'out' label.
Signed-off-by: NTushar Behera <tushar.b@samsung.com>
Reviewed-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

probe_err label only returns the error code. This label can be removed
and the error code can be returned directly.
Signed-off-by: NTushar Behera <tushar.b@samsung.com>
Reviewed-by: NSachin Kamat <sachin.kamat@samsung.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>