Commit Graph

7 Commits

Author SHA1 Message Date
Johannes Thumshirn
2b9a8508cb tty: serial: men_z135_uart.c: Don't initialize port->lock
port->lock get's initialized in uart_add_one_port(), no need to do it
in men_z135_probe().

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-14 17:14:13 -07:00
Johannes Thumshirn
8117e34740 tty: serial: men_z135_uart.c: Fix race between IRQ and set_termios()
Fix panic caused by a race between men_z135_intr() and men_z135_set_termios().

men_z135_intr() and men_z135_set_termios() both hold the struct uart_port::lock
spinlock, but men_z135_intr() does a spin_lock_irqsave() and
men_z135_set_termios() does a normal spin_lock(), which can lead to a deadlock
when an interrupt is called while the lock is being helt by
men_z135_set_termios().

This was discovered using a insmod, hardware looppback send/receive, rmmod
stress test.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Cc: Andreas Werner <andreas.werner@men.de>
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-14 17:14:13 -07:00
Johannes Thumshirn
01ba8d6af4 tty: serial: men_z135_uart: Fix driver for changes in hardware
16z135 IP Core has changed so the driver needs to be updated to respect
these changes. The following changes have been made:

* Don't invert the 16z135 modem status register when reading.
* Add module parameter to configure the (baud rate dependent) RX timeout.
  Character timeout in seconds = (timeout_reg * baud_reg * 4)/freq_reg.
* Enable the handling of UART core's automatic flow control feature.
  When AFE is active disable generation of modem status IRQs.
* Rework the handling of IRQs to be conform with newer FPGA versions and
  take precautions not to miss an interrupt because of the destructive read
  of the IIR register.
* Correct men_z135_handle_modem_status(), MSR is stat_reg[15:8] not
  stat_reg[7:0]
* Correct calling of uart_handle_{dcd,cts}_change()
* Reset CLOCAL when CRTSCTS is set

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@men.de>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:27 -08:00
Axel Lin
6b1f40cf48 tty: serial: men_z135_uart: Add terminating entry for men_z135_ids
The mcb_device_id table is supposed to be zero-terminated.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-25 17:06:38 -08:00
Johannes Thumshirn
a9977620a4 tty: serial: men_z135_uart: Wakeup UART after transmitting
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: Jun Shih <Jun.Shih@pason.com>
Tested-by: Jun Shih <Jun.Shih@pason.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@men.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09 17:35:42 -07:00
Johannes Thumshirn
10389e6623 tty: serial: men_z135_uart: Don't activate TX Space available IRQ on startup
Don't activate the TX Space available IRQ on startup, or a simple
$ cat /dev/ttyHSU0
will cause an endless amount of IRQs, as there is always space in
the TX FIFO available if no data is going to be sent.

Also correct comments for IRQ names (RX and TX swapped).

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@men.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-28 12:27:22 -07:00
Johannes Thumshirn
e264ebf4c8 tty: serial: Add driver for MEN's 16z135 High Speed UART.
Add driver for MEN's 16z135 High Speed UART.

The 16z135 is a memory mapped UART Core on an MCB FPGA and has 1024 byte
deep FIFO buffers for the RX and TX path. It also has configurable FIFO
fill level IRQs and data copied to and from the hardware has to be
acknowledged.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@men.de>
Reviewed-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-24 16:24:25 -07:00