linux-stable.git/drivers/tty/serial, branch v4.12.2

imx-serial: RX DMA startup latency

2017-07-15T11:09:04+00:00

commit 4dec2f119e86f9c91e60cdd8f0cc057452e331a9 upstream.

18a4208 introduced a change to reduce the RX DMA latency on the first reception
when the serial port was opened for reading. However it was claiming a hardirq
unsafe lock after a hardirq safe lock which is not allowed and causes lockdep
to complain verbosely.

This patch changes the code to always start RX DMA earlier, instead of
relying on the flags used to open the serial port removing the code that
was looking for the serial file flags.

Signed-off-by: Peter Senna Tschudin 
Tested-by: Sascha Hauer 
Signed-off-by: Fabio Estevam 
Signed-off-by: Greg Kroah-Hartman

serial: altera_uart: call iounmap() at driver remove

2017-05-25T12:36:37+00:00

The driver calls ioremap() in the probe function but doesn't call
iounmap() in the remove function correspondingly. Do so now.

Follow commit 5c9d6abed9e0 ("serial: altera_jtaguart: adding iounmap()")

Cc: Alexey Khoroshilov 
Signed-off-by: Tobias Klauser 
Signed-off-by: Greg Kroah-Hartman

serial: imx: ensure UCR3 and UFCR are setup correctly

2017-05-25T12:35:53+00:00

Commit e61c38d85b73 ("serial: imx: setup DCEDTE early and ensure DCD and
RI irqs to be off") has a flaw: While UCR3 and UFCR were modified using
read-modify-write before it switched to write register values
independent of the previous state. That's a good idea in principle (and
that's why I did it) but needs more care.

This patch reinstates read-modify-write for UFCR and for UCR3 ensures
that RXDMUXSEL and ADNIMP are set for post imx1.

Fixes: e61c38d85b73 ("serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off")
Signed-off-by: Uwe Kleine-König 
Acked-by: Mika Penttilä 
Tested-by: Mika Penttilä 
Acked-by: Steve Twiss 
Tested-by: Steve Twiss 
Signed-off-by: Greg Kroah-Hartman

serial: enable serdev support

2017-05-18T15:38:25+00:00

Enable serdev support by using the new device-registration helpers.

Reviewed-by: Rob Herring 
Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman

serial: core: fix crash in uart_suspend_port

2017-05-18T14:43:55+00:00

With serdev we might end up with serial ports that have no cdev exported
to userspace, as they are used as the bus interface to other devices. In
that case serial_match_port() won't be able to find a matching tty_dev.

Skip the irq wakeup enabling in that case, as serdev will make sure to
keep the port active, as long as there are devices depending on it.

Fixes: 8ee3fde04758 (tty_port: register tty ports with serdev bus)
Signed-off-by: Lucas Stach 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

serial: ifx6x60: fix use-after-free on module unload

2017-05-18T14:43:55+00:00

Make sure to deregister the SPI driver before releasing the tty driver
to avoid use-after-free in the SPI remove callback where the tty
devices are deregistered.

Fixes: 72d4724ea54c ("serial: ifx6x60: Add modem power off function in the platform reboot process")
Cc: stable      # 3.8
Cc: Jun Chen 
Signed-off-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman

serial: altera_jtaguart: adding iounmap()

2017-05-18T14:43:55+00:00

The driver does ioremap(port->mapbase, ALTERA_JTAGUART_SIZE),
but there is no any iounmap().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov 
Acked-by: Tobias Klauser 
Signed-off-by: Greg Kroah-Hartman

serial: exar: Fix stuck MSIs

2017-05-18T14:43:55+00:00

After migrating 8250_exar to MSI in 172c33cb61da, we can get stuck
without further interrupts because of the special wake-up event these
chips send. They are only cleared by reading INT0. As we fail to do so
during startup and shutdown, we can leave the interrupt line asserted,
which is fatal with edge-triggered MSIs.

Add the required reading of INT0 to startup and shutdown. Also account
for the fact that a pending wake-up interrupt means we have to return 1
from exar_handle_irq. Drop the unneeded reading of INT1..3 along with
this - those never reset anything.

An alternative approach would have been disabling the wake-up interrupt.
Unfortunately, this feature (REGB[17] = 1) is not available on the
XR17D15X.

Fixes: 172c33cb61da ("serial: exar: Enable MSI support")
Signed-off-by: Jan Kiszka 
Reviewed-by: Andy Shevchenko 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

serial: efm32: Fix parity management in 'efm32_uart_console_get_options()'

2017-05-18T14:43:55+00:00

UARTn_FRAME_PARITY_ODD is 0x0300
UARTn_FRAME_PARITY_EVEN is 0x0200
So if the UART is configured for EVEN parity, it would be reported as ODD.
Fix it by correctly testing if the 2 bits are set.

Fixes: 3afbd89c9639 ("serial/efm32: add new driver")
Signed-off-by: Christophe JAILLET 
Acked-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman

drivers/tty: 8250: only call fintek_8250_probe when doing port I/O

2017-05-18T14:39:10+00:00

Commit fa01e2ca9f53 ("serial: 8250: Integrate Fintek into 8250_base")
modified the probing logic for PNP0501 devices, to remove a collision
between the generic 16550A driver and the Fintek driver, which reused
the same ACPI _HID.

The Fintek device probe is now incorporated into the common 8250 probe
path, and gets called for all discovered 16550A compatible devices,
including ones that are MMIO mapped rather than IO mapped. However,
the Fintek driver assumes the port base is a I/O address, and proceeds
to probe some arbitrary offsets above it.

This is generally a wrong thing to do, but on ARM systems (having no
native port I/O), this may result in faulting accesses of completely
unrelated MMIO regions in the PCI I/O space. Given that this is at
serial probe time, this results in hard to diagnose crashes at boot.

So let's restrict the Fintek probe to devices that we know are using
port I/O in the first place.

Fixes: fa01e2ca9f53 ("serial: 8250: Integrate Fintek into 8250_base")
Suggested-by: Arnd Bergmann 
Reviewed-by: Ricardo Ribalda 
Signed-off-by: Ard Biesheuvel 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman