linux-stable.git/drivers/tty/serial, branch v3.2.38

8250/16?50: Add support for Broadcom TruManage redirected serial port

2013-02-06T04:33:36+00:00

commit ebebd49a8eab5e9aa1b1f8f1614ccc3c2120f886 upstream.

Add support for the UART device present in Broadcom TruManage capable
NetXtreme chips (ie: 5761m 5762, and 5725).

This implementation has a hidden transmit FIFO, so running in single-byte
interrupt mode results in too many interrupts.  The UART_CAP_HFIFO
capability was added to track this.  It continues to reload the THR as long
as the THRE and TSRE bits are set in the LSR up to a specified limit (1024
is used here).

Signed-off-by: Stephen Hurd 
Signed-off-by: Michael Chan 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2:
 - Adjust filenames
 - Adjust context
 - First available port type number is 22 not 24
 - s/uart_8250_port/uart_port/
 - Use serial_in() not serial_port_in()]
Signed-off-by: Ben Hutchings

tty: 8250_dw: Fix inverted arguments to serial_out in IRQ handler

2013-02-06T04:33:34+00:00

commit 68e56cb3a068f9c30971c6117fbbd1e32918e49e upstream.

Signed-off-by: Maxime Ripard 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings

serial:ifx6x60:Delete SPI timer when shut down port

2013-02-06T04:33:34+00:00

commit 014b9b4ce84281ccb3d723c792bed19815f3571a upstream.

When shut down SPI port, it's possible that MRDY has been asserted and a SPI
timer was activated waiting for SRDY assert, in the case, it needs to delete
this timer.

Signed-off-by: Chen Jun 
Signed-off-by: channing 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

serial: pl011: handle corruption at high clock speeds

2012-10-17T02:49:02+00:00

commit c5dd553b9fd069892c9e2de734f4f604e280fa7a upstream.

This works around a few glitches in the ST version of the PL011
serial driver when using very high baud rates, as we do in the
Ux500: 3, 3.25, 4 and 4.05 Mbps.

Problem Observed/rootcause:

When using high baud-rates, and the baudrate*8 is getting close to
the provided clock frequency (so a division factor close to 1), when
using bursts of characters (so they are abutted), then it seems as if
there is not enough time to detect the beginning of the start-bit which
is a timing reference for the entire character, and thus the sampling
moment of character bits is moving towards the end of each bit, instead
of the middle.

Fix:
Increase slightly the RX baud rate of the UART above the theoretical
baudrate by 5%. This will definitely give more margin time to the
UART_RX to correctly sample the data at the middle of the bit period.

Also fix the ages old copy-paste error in the very stressed comment,
it's referencing the registers used in the PL010 driver rather than
the PL011 ones.

Signed-off-by: Guillaume Jaunet 
Signed-off-by: Christophe Arnal 
Signed-off-by: Matthias Locher 
Signed-off-by: Rajanikanth HV 
Cc: Bibek Basu 
Cc: Par-Gunnar Hjalmdahl 
Signed-off-by: Linus Walleij 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

serial: set correct baud_base for EXSYS EX-41092 Dual 16950

2012-10-17T02:49:01+00:00

commit 26e8220adb0aec43b7acafa0f1431760eee28522 upstream.

Apparently the same card model has two IDs, so this patch
complements the commit 39aced68d664291db3324d0fcf0985ab5626aac2
adding the missing one.

Signed-off-by: Flavio Leitner 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings

pch_uart: Add eg20t_port lock field, avoid recursive spinlocks

2012-10-10T02:31:12+00:00

commit 2588aba002d14e938c2f56d299ecf3e7ce1302a5 upstream.

pch_uart_interrupt() takes priv->port.lock which leads to two recursive
spinlock calls if low_latency==1 or CONFIG_PREEMPT_RT_FULL=y (one
otherwise):

pch_uart_interrupt
  spin_lock_irqsave(priv->port.lock, flags)
  case PCH_UART_IID_RDR_TO (data ready)
  handle_rx_to
    push_rx
      tty_port_tty_get
        spin_lock_irqsave(&port->lock, flags) <--- already hold this lock
        ...
      tty_flip_buffer_push
        ...
        flush_to_ldisc
          spin_lock_irqsave(&tty->buf.lock)
            spin_lock_irqsave(&tty->buf.lock)
            disc->ops->receive_buf(tty, char_buf)
              n_tty_receive_buf
                tty->ops->flush_chars()
                uart_flush_chars
                  uart_start
                    spin_lock_irqsave(&port->lock) <--- already hold this lock

Avoid this by using a dedicated lock to protect the eg20t_port structure
and IO access to its membase. This is more consistent with the 8250
driver.  Ensure priv->lock is always take prior to priv->port.lock when
taken at the same time.

V2: Remove inadvertent whitespace change.
V3: Account for oops_in_progress for the private lock in
    pch_console_write().

Note: Like the 8250 driver, if a printk is introduced anywhere inside
      the pch_console_write() critical section, the kernel will hang
      on a recursive spinlock on the private lock. The oops case is
      handled by using a trylock in the oops_in_progress case.

Signed-off-by: Darren Hart 
CC: Tomoya MORINAGA 
CC: Feng Tang 
CC: Alexander Stein 
Acked-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2:
 - Adjust context
 - Drop changes to pch_console_write()]
Signed-off-by: Ben Hutchings

tty: serial: imx: don't reinit clock in imx_setup_ufcr()

2012-09-19T14:05:14+00:00

commit 7be0670f7b9198382938a03ff3db7f47ef6b4780 upstream.

Remove the clock configuration from imx_setup_ufcr(). This
isn't needed here and will cause garbage output if done.

To be be sure that we only touch the bits we want (TXTL and RXTL)
we have to mask out all other bits of the UFCR register. Add
one non-existing bit macro for this, too (bit 6, DCEDTE on i.MX6).

Signed-off-by: Dirk Behme 
CC: Shawn Guo 
CC: Sascha Hauer 
CC: Troy Kisky 
CC: Xinyu Chen 
Acked-by: Shawn Guo 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: deleted code in imx_setup_ufcr() refers to
 sport->clk not sport->clk_per]
Signed-off-by: Ben Hutchings

tty: serial: imx: console write routing is unsafe on SMP

2012-09-19T14:05:14+00:00

commit 9ec1882df244c4ee1baa692676fef5e8b0f5487d upstream.

The console feature's write routing is unsafe on SMP with
the startup/shutdown call.

There could be several consumers of the console
* the kernel printk
* the init process using /dev/kmsg to call printk to show log
* shell, which open /dev/console and write with sys_write()

The shell goes into the normal uart open/write routing,
but the other two go into the console operations.
The open routing calls imx serial startup, which will write USR1/2
register without any lock and critical with imx_console_write call.

Add a spin_lock for startup/shutdown/console_write routing.

This patch is a port from Freescale's Android kernel.

Signed-off-by: Xinyu Chen 
Tested-by: Dirk Behme 
CC: Sascha Hauer 
Acked-by: Shawn Guo 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

pmac_zilog,kdb: Fix console poll hook to return instead of loop

2012-09-12T02:37:34+00:00

commit 38f8eefccf3a23c4058a570fa2938a4f553cf8e0 upstream.

kdb <-> kgdb transitioning does not work properly with this UART
driver because the get character routine loops indefinitely as opposed
to returning NO_POLL_CHAR per the expectation of the KDB I/O driver
API.

The symptom is a kernel hang when trying to switch debug modes.

Cc: Alan Cox 
Signed-off-by: Jason Wessel 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

pch_uart: Fix parity setting issue

2012-08-09T23:25:19+00:00

commit 38bd2a1ac736901d1cf4971c78ef952ba92ef78b upstream.

Parity Setting value is reverse.
E.G. In case of setting ODD parity, EVEN value is set.
This patch inverts "if" condition.

Signed-off-by: Tomoya MORINAGA 
Acked-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings