linux-toradex.git/drivers/tty, branch v3.2.56

TTY: pmac_zilog, check existence of ports in pmz_console_init()

2014-04-01T23:59:00+00:00

commit dc1dc2f8a5dd863bf2e79f338fc3ae29e99c683a upstream.

When booting a multi-platform m68k kernel on a non-Mac with "console=ttyS0"
on the kernel command line, it crashes with:

Unable to handle kernel NULL pointer dereference at virtual address   (null)
Oops: 00000000
PC: [<0013ad28>] __pmz_startup+0x32/0x2a0
...
Call Trace: [<002c5d3e>] pmz_console_setup+0x64/0xe4

The normal tty driver doesn't crash, because init_pmz() checks
pmz_ports_count again after calling pmz_probe().

In the serial console initialization path, pmz_console_init() doesn't do
this, causing the driver to crash later.

Add a check for pmz_ports_count to fix this.

Signed-off-by: Geert Uytterhoeven 
Cc: Finn Thain 
Cc: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

tty: n_gsm: Fix for modems with brk in modem status control

2014-04-01T23:58:49+00:00

commit 3ac06b905655b3ef2fd2196bab36e4587e1e4e4f upstream.

3GPP TS 07.10 states in section 5.4.6.3.7:
"The length byte contains the value 2 or 3 ... depending on the break
signal." The break byte is optional and if it is sent, the length is
3. In fact the driver was not able to work with modems that send this
break byte in their modem status control message. If the modem just
sends the break byte if it is really set, then weird things might
happen.
The code for deconding the modem status to the internal linux
presentation in gsm_process_modem has already a big comment about
this 2 or 3 byte length thing and it is already able to decode the
brk, but the code calling the gsm_process_modem function in
gsm_control_modem does not encode it and hand it over the right way.
This patch fixes this.
Without this fix if the modem sends the brk byte in it's modem status
control message the driver will hang when opening a muxed channel.

Signed-off-by: Lars Poeschel 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

serial: 8250: enable UART_BUG_NOMSR for Tegra

2014-04-01T23:58:41+00:00

commit 3685f19e07802ec4207b52465c408f185b66490e upstream.

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  # autotester
Signed-off-by: Stephen Warren 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2:
 - Adjust filename
 - s/port->/up->port./]
Signed-off-by: Ben Hutchings

serial: add support for 200 v3 series Titan card

2014-04-01T23:58:40+00:00

commit 48c0247d7b7bf58abb85a39021099529df365c4d upstream.

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

serial: add support for 400 and 800 v3 series Titan cards

2014-04-01T23:58:39+00:00

commit 1e9deb118ed76b9df89d189f27a06522a03cf743 upstream.

add support for 400Hv3, 410Hv3 and 800Hv3

Signed-off-by: Yegor Yefremov 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

serial: pch_uart: fix tty-kref leak in dma-rx path

2013-10-26T20:06:05+00:00

commit 19b85cfb190eb9980eaf416bff96aef4159a430e upstream.

Fix tty_kref leak when tty_buffer_request room fails in dma-rx path.

Note that the tty ref isn't really needed anymore, but as the leak has
always been there, fixing it before removing should makes it easier to
backport the fix.

Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

serial: pch_uart: fix tty-kref leak in rx-error path

2013-10-26T20:06:05+00:00

commit fc0919c68cb2f75bb1af759315f9d7e2a9443c28 upstream.

Fix tty-kref leak introduced by commit 384e301e ("pch_uart: fix a
deadlock when pch_uart as console") which never put its tty reference.

Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

powerpc/hvsi: Increase handshake timeout from 200ms to 400ms.

2013-09-10T00:57:34+00:00

commit d220980b701d838560a70de691b53be007e99e78 upstream.

This solves a problem observed in kexec'ed kernel where 200ms timeout is
too short and bootconsole fails to initialize. Console did eventually
become workable but much later into the boot process.

Observed timeout was around 260ms, but I decided to make it a little bigger
for more reliability.

This has been tested on Power7 machine with Petitboot as a primary
bootloader and PowerNV firmware.

Signed-off-by: Eugene Surovegin 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Ben Hutchings

serial/mxs-auart: increase time to wait for transmitter to become idle

2013-09-10T00:57:15+00:00

commit 079a036f4283e2b0e5c26080b8c5112bc0cc1831 upstream.

Without this patch the driver waits ~1 ms for the UART to become idle. At
115200n8 this time is (theoretically) enough to transfer 11.5 characters
(= 115200 bits/s / (10 Bits/char) * 1ms). As the mxs-auart has a fifo size
of 16 characters the clock is gated too early. The problem is worse for
lower baud rates.

This only happens to really shut down the transmitter in the middle of a
transfer if /dev/ttyAPPx isn't opened in userspace (e.g. by a getty) but
was at least once (because the bootloader doesn't disable the transmitter).

So increase the timeout to 20 ms which should be enough for 9600n8, too.
Moreover skip gating the clock if the timeout is elapsed.

Signed-off-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings

serial/mxs-auart: fix race condition in interrupt handler

2013-09-10T00:57:15+00:00

commit d970d7fe65adff5efe75b4a73c4ffc9be57089f7 upstream.

The handler needs to ack the pending events before actually handling them.
Otherwise a new event might come in after it it considered non-pending or
handled and is acked then without being handled. So this event is only
noticed when the next interrupt happens.

Without this patch an i.MX28 based machine running an rt-patched kernel
regularly hangs during boot.

Signed-off-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Ben Hutchings