linux-toradex.git/drivers/tty/serial, branch v4.9.89

serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off

2018-03-22T08:17:49+00:00

[ Upstream commit e61c38d85b7392e033ee03bca46f1d6006156175 ]

If the UART is operated in DTE mode and UCR3_DCD or UCR3_RI are 1 (which
is the reset default) and the opposite side pulls the respective line to
its active level the irq triggers after it is requested in .probe.

These irqs were already disabled in .startup but this might be too late.

Also setup of the UFCR_DCEDTE bit (currently done in .set_termios) is
done very late which is critical as it also controls direction of some
pins.

So setup UFCR_DCEDTE earlier (in .probe) and also disable the broken
irqs in DTE mode there before requesting irqs.

Acked-by: Lucas Stach 
Signed-off-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

tty: amba-pl011: Fix spurious TX interrupts

2018-03-22T08:17:49+00:00

[ Upstream commit 7d05587c9e0e4611650bb403812e2d492c178a9f ]

On SMP systems, we see a lot of spurious TX interrupts when a
program generates a steady stream of output to the pl011 UART.

The problem can be easily seen when one CPU generates the output
while another CPU handles the pl011 interrupts, and the rate of
output is low enough not to fill the TX FIFO. The problem seems
to be:

    -- CPU a --                        -- CPU b --
   (take port lock)
   pl011_start_tx
      pl011_start_tx_pio
         enable TXIM in REG_IMSC   ->  causes uart tx intr (pl011_int)
         pl011_tx_chars                pl011_int
            ...tx chars, all done...       (wait for port lock)
            pl011_stop_tx                   .
               disable TXIM                 .
    (release port lock)            ->      (take port lock)
                                           check for TXIM, not enabled
                                           (release port lock)
                                           return IRQ_NONE

Enabling the TXIM in pl011_start_tx_pio() causes the interrupt
to be generated and delivered to CPU b, even though pl011_tx_chars()
is able to complete the TX and then disable the tx interrupt.

Fix this by enabling TXIM only after pl011_tx_chars, if it is needed.
pl011_tx_chars will return a boolean indicating whether the TX
interrupts have to be enabled.

Debugged-by: Vijaya Kumar 
Signed-off-by: Jayachandran C 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

earlycon: add reg-offset to physical address before mapping

2018-03-18T10:18:56+00:00

commit 1f66dd36bb18437397ea0d7882c52f7e3c476e15 upstream.

It will get the wrong virtual address because port->mapbase is not added
the correct reg-offset yet. We have to update it before earlycon_map()
is called

Signed-off-by: Greentime Hu 
Acked-by: Arnd Bergmann 
Cc: Peter Hurley 
Cc: stable@vger.kernel.org
Fixes: 088da2a17619 ("of: earlycon: Initialize port fields from DT properties")
Acked-by: Rob Herring 
Signed-off-by: Greg Kroah-Hartman

serial: core: mark port as initialized in autoconfig

2018-03-18T10:18:56+00:00

commit 714569064adee3c114a2a6490735b94abe269068 upstream.

This is a followup on 44117a1d1732 ("serial: core: mark port as
initialized after successful IRQ change").
Nikola has been using autoconfig via setserial and reported a crash
similar to what I fixed in the earlier mentioned commit. Here I do the
same fixup for the autoconfig. I wasn't sure that this is the right
approach. Nikola confirmed that it fixes his crash.

Fixes: b3b576461864 ("tty: serial_core: convert uart_open to use tty_port_open")
Link: http://lkml.kernel.org/r/20180131072000.GD1853@localhost.localdomain
Reported-by: Nikola Ciprich 
Tested-by: Nikola Ciprich 
Cc: 
Signed-off-by: Sebastian Andrzej Siewior 
Tested-by: Nikola Ciprich 
Acked-by: Johan Hovold 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: Add Brainboxes UC-260 4 port serial device

2018-03-18T10:18:56+00:00

commit 9f2068f35729948bde84d87a40d135015911345d upstream.

Add PCI ids for two variants of Brainboxes UC-260 quad port
PCI serial cards.

Suggested-by: Andy Shevchenko 
Signed-off-by: Nikola Ciprich 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

tty/serial: atmel: add new version check for usart

2018-03-18T10:18:55+00:00

commit fd63a8903a2c40425a9811c3371dd4d0f42c0ad3 upstream.

On our at91sam9260 based board the usart0 and usart1 ports report
their versions (ATMEL_US_VERSION) as 0x10302. This version is not
included in the current checks in the driver.

Signed-off-by: Jonas Danielsson 
Acked-by: Richard Genoud 
Acked-by: Nicolas Ferre 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: prevent lockup on full TTY buffers

2018-03-18T10:18:55+00:00

commit 7842055bfce4bf0170d0f61df8b2add8399697be upstream.

When the TTY buffers fill up to the configured maximum, a system lockup
occurs:

[  598.820128] INFO: rcu_preempt detected stalls on CPUs/tasks:
[  598.825796]  0-...!: (1 GPs behind) idle=5a6/2/0 softirq=1974/1974 fqs=1
[  598.832577]  (detected by 3, t=62517 jiffies, g=296, c=295, q=126)
[  598.838755] Task dump for CPU 0:
[  598.841977] swapper/0       R  running task        0     0      0 0x00000022
[  598.849023] Call trace:
[  598.851476]  __switch_to+0x98/0xb0
[  598.854870]            (null)

This can be prevented by doing a dummy read of the RX data register.

This issue affects both HSCIF and SCIF ports. Reported for R-Car H3 ES2.0;
reproduced and fixed on H3 ES1.1. Probably affects other R-Car platforms
as well.

Reported-by: Yoshihiro Shimoda 
Signed-off-by: Ulrich Hecht 
Reviewed-by: Geert Uytterhoeven 
Cc: stable 
Tested-by: Nguyen Viet Dung 
Signed-off-by: Greg Kroah-Hartman

serial: core: mark port as initialized after successful IRQ change

2018-02-13T11:35:56+00:00

commit 44117a1d1732c513875d5a163f10d9adbe866c08 upstream.

setserial changes the IRQ via uart_set_info(). It invokes
uart_shutdown() which free the current used IRQ and clear
TTY_PORT_INITIALIZED. It will then update the IRQ number and invoke
uart_startup() before returning to the caller leaving
TTY_PORT_INITIALIZED cleared.

The next open will crash with
|  list_add double add: new=ffffffff839fcc98, prev=ffffffff839fcc98, next=ffffffff839fcc98.
since the close from the IOCTL won't free the IRQ (and clean the list)
due to the TTY_PORT_INITIALIZED check in uart_shutdown().

There is same pattern in uart_do_autoconfig() and I *think* it also
needs to set TTY_PORT_INITIALIZED there.
Is there a reason why uart_startup() does not set the flag by itself
after the IRQ has been acquired (since it is cleared in uart_shutdown)?

Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Greg Kroah-Hartman

serial: imx: Only wakeup via RTSDEN bit if the system has RTS/CTS

2018-02-03T16:05:43+00:00

commit 38b1f0fb42f772b8c9aac53593883a18ff5eb9d7 upstream.

The wakeup mechanism via RTSDEN bit relies on the system using the RTS/CTS
lines, so only allow such wakeup method when the system actually has
RTS/CTS support.

Fixes: bc85734b126f ("serial: imx: allow waking up on RTSD")
Signed-off-by: Fabio Estevam 
Reviewed-by: Martin Kaiser 
Acked-by: Fugang Duan 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Preserve DLD[7:4] for PORT_XR17V35X

2017-12-09T21:01:48+00:00

[ Upstream commit 0ab84da2e076948c49d36197ee7d254125c53eab ]

The upper four bits of the XR17V35x fractional divisor register (DLD)
control general chip function (RS-485 direction pin polarity, multidrop
mode, XON/XOFF parity check, and fast IR mode). Don't allow these bits
to be clobbered when setting the baudrate.

Signed-off-by: Aaron Sierra 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman