linux-stable.git/drivers/tty, branch v4.9.166

serial: sprd: clear timeout interrupt only rather than all interrupts

2019-03-27T05:13:04+00:00

commit 4350782570b919f254c1e083261a21c19fcaee90 upstream.

On Spreadtrum's serial device, nearly all of interrupts would be cleared
by hardware except timeout interrupt.  This patch removed the operation
of clearing all interrupt in irq handler, instead added an if statement
to check if the timeout interrupt is supposed to be cleared.

Wrongly clearing timeout interrupt would lead to uart data stay in rx
fifo, that means the driver cannot read them out anymore.

Signed-off-by: Lanqing Liu 
Signed-off-by: Chunyan Zhang 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

serial: sprd: adjust TIMEOUT to a big value

2019-03-27T05:13:04+00:00

commit e1dc9b08051a2c2e694edf48d1e704f07c7c143c upstream.

SPRD_TIMEOUT was 256, which is too small to wait until the status
switched to workable in a while loop, so that the earlycon could
not work correctly.

Signed-off-by: Wei Qiao 
Signed-off-by: Chunyan Zhang 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: Have ACCES cards that use the four port Pericom PI7C9X7954 chip use the pci_pericom_setup()

2019-03-23T12:19:51+00:00

commit 78d3820b9bd39028727c6aab7297b63c093db343 upstream.

The four port Pericom chips have the fourth port at the wrong address.
Make use of quirk to fix it.

Fixes: c8d192428f52 ("serial: 8250: added acces i/o products quad and octal serial cards")
Cc: stable 
Signed-off-by: Jay Dolan 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_pci: Fix number of ports for ACCES serial cards

2019-03-23T12:19:51+00:00

commit b896b03bc7fce43a07012cc6bf5e2ab2fddf3364 upstream.

Have the correct number of ports created for ACCES serial cards. Two port
cards show up as four ports, and four port cards show up as eight.

Fixes: c8d192428f52 ("serial: 8250: added acces i/o products quad and octal serial cards")
Signed-off-by: Jay Dolan 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

8250: FIX Fourth port offset of Pericom PI7C9X7954 boards

2019-03-23T12:19:50+00:00

commit 5c31ef91c06db7800ad573174bd92be4df34ecb2 upstream.

Hi,
below patch to fix Fourth port offset of Percom PI7C9X7954 boards.

I had a problem using Fourth port on a pci express serial board based on Pericom
PI7C9X7954. Reading datasheet I notice a "special" offset assign to this port
when used in I/O mode.

Offset 0x0 ->  UART 0
Offset 0x8 ->  UART 1
Offset 0x10 ->  UART 2
Offset 0x38 ->  UART 3  <<---- This don't follow a logical sequence

This patch add a different init to last port, to have right offset.

I check also Pericom 7952 and 7958 but that devices follow logical sequence,
so they are ok.

Regards,
Angelo

Signed-off-by: Angelo Butti 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_of: assume reg-shift of 2 for mrvl,mmp-uart

2019-03-23T12:19:50+00:00

commit f4817843e39ce78aace0195a57d4e8500a65a898 upstream.

There are two other drivers that bind to mrvl,mmp-uart and both of them
assume register shift of 2 bits. There are device trees that lack the
property and rely on that assumption.

If this driver wins the race to bind to those devices, it should behave
the same as the older deprecated driver.

Signed-off-by: Lubomir Rintel 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

serial: uartps: Fix stuck ISR if RX disabled with non-empty FIFO

2019-03-23T12:19:50+00:00

commit 7abab1605139bc41442864c18f9573440f7ca105 upstream.

If RX is disabled while there are still unprocessed bytes in RX FIFO,
cdns_uart_handle_rx() called from interrupt handler will get stuck in
the receive loop as read bytes will not get removed from the RX FIFO
and CDNS_UART_SR_RXEMPTY bit will never get set.

Avoid the stuck handler by checking first if RX is disabled. port->lock
protects against race with RX-disabling functions.

This HW behavior was mentioned by Nathan Rossi in 43e98facc4a3 ("tty:
xuartps: Fix RX hang, and TX corruption in termios call") which fixed a
similar issue in cdns_uart_set_termios().
The behavior can also be easily verified by e.g. setting
CDNS_UART_CR_RX_DIS at the beginning of cdns_uart_handle_rx() - the
following loop will then get stuck.

Resetting the FIFO using RXRST would not set RXEMPTY either so simply
issuing a reset after RX-disable would not work.

I observe this frequently on a ZynqMP board during heavy RX load at 1M
baudrate when the reader process exits and thus RX gets disabled.

Fixes: 61ec9016988f ("tty/serial: add support for Xilinx PS UART")
Signed-off-by: Anssi Hannula 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

serial: fsl_lpuart: fix maximum acceptable baud rate with over-sampling

2019-03-05T16:57:05+00:00

[ Upstream commit 815d835b7ba46685c316b000013367dacb2b461b ]

Using over-sampling ratio, lpuart can accept baud rate upto uartclk / 4.

Signed-off-by: Tomonori Sakita 
Signed-off-by: Atsushi Nemoto 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: fix race between flush_to_ldisc and tty_open

2019-02-12T18:45:02+00:00

commit fedb5760648a291e949f2380d383b5b2d2749b5e upstream.

There still is a race window after the commit b027e2298bd588
("tty: fix data race between tty_init_dev and flush of buf"),
and we encountered this crash issue if receive_buf call comes
before tty initialization completes in tty_open and
tty->driver_data may be NULL.

CPU0                                    CPU1
----                                    ----
                                  tty_open
                                   tty_init_dev
                                     tty_ldisc_unlock
                                       schedule
flush_to_ldisc
 receive_buf
  tty_port_default_receive_buf
   tty_ldisc_receive_buf
    n_tty_receive_buf_common
      __receive_buf
       uart_flush_chars
        uart_start
        /*tty->driver_data is NULL*/
                                   tty->ops->open
                                   /*init tty->driver_data*/

it can be fixed by extending ldisc semaphore lock in tty_init_dev
to driver_data initialized completely after tty->ops->open(), but
this will lead to get lock on one function and unlock in some other
function, and hard to maintain, so fix this race only by checking
tty->driver_data when receiving, and return if tty->driver_data
is NULL, and n_tty_receive_buf_common maybe calls uart_unthrottle,
so add the same check.

Because the tty layer knows nothing about the driver associated with the
device, the tty layer can not do anything here, it is up to the tty
driver itself to check for this type of race.  Fix up the serial driver
to correctly check to see if it is finished binding with the device when
being called, and if not, abort the tty calls.

[Description and problem report and testing from Li RongQing, I rewrote
the patch to be in the serial layer, not in the tty core - gregkh]

Reported-by: Li RongQing 
Tested-by: Li RongQing 
Signed-off-by: Wang Li 
Signed-off-by: Zhang Yu 
Signed-off-by: Li RongQing 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

tty: serial: samsung: Properly set flags in autoCTS mode

2019-02-12T18:44:55+00:00

[ Upstream commit 31e933645742ee6719d37573a27cce0761dcf92b ]

Commit 391f93f2ec9f ("serial: core: Rework hw-assited flow control support")
has changed the way the autoCTS mode is handled.

According to that change, serial drivers which enable H/W autoCTS mode must
set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling
TX. This patch adds proper handling of UPSTAT_AUTOCTS flag.

Signed-off-by: Beomho Seo 
[mszyprow: rephrased commit message]
Signed-off-by: Marek Szyprowski 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin