talos-obmc-linux/drivers/tty/serial, branch dev-4.13

serial: 8250: Add Nuvoton NPCM UART

2018-04-11T03:42:46+00:00

The Nuvoton UART is almost compatible with the 8250 driver when probed via the 8250_of driver, however it requires some extra configuration at startup. Reviewed-by: Rob Herring Signed-off-by: Joel Stanley Cc: stable Signed-off-by: Greg Kroah-Hartman (cherry picked from commit f597fbce38d230af95384f4a04e0a13a1d0ad45d) Signed-off-by: Joel Stanley

serial/aspeed-vuart: Implement quick throttle mechanism

2018-04-05T13:19:09+00:00

Although we populate the ->throttle and ->unthrottle UART operations, these may not be called until the ldisc has had a chance to schedule and check buffer space. This means that we may overflow the flip buffers without ever hitting the ldisc's throttle threshold. This change implements an interrupt-based throttle, where we check for space in the flip buffers before reading characters from the UART's FIFO. If there's no space available, we disable the RX interrupt and schedule a timer to check for space later. This prevents a case where we drop characters under heavy RX load. OpenBMC-Staging-Count: 1 Signed-off-by: Jeremy Kerr Tested-by: Eddie James Signed-off-by: Andrew Jeffery

serial/aspeed-vuart: Implement rx throttling

2018-04-05T13:19:01+00:00

The aspeed VUART runs at LPC bus frequency, rather than being restricted to a typical UART baud rate. This means that the VUART can receive a lot of data, which can overrun tty flip buffers, and/or cause a large amount of interrupt traffic. This change implements the uart_port->throttle & unthrottle callbacks, implemented by disabling the receiver line status & received data available IRQs. OpenBMC-Staging-Count: 1 Signed-off-by: Jeremy Kerr Tested-by: Eddie James Signed-off-by: Andrew Jeffery

serial/8250: export serial8250_read_char

2018-04-05T13:18:55+00:00

Currently, we export serial8250_rx_chars, which does a whole bunch of reads from the 8250 data register, without any form of flow control between reads. An upcoming change to the aspeed vuart driver implements more fine-grained flow control in the interrupt handler, requiring character-at-a-time control over the rx path. This change exports serial8250_read_char to allow this. OpenBMC-Staging-Count: 1 Signed-off-by: Jeremy Kerr Tested-by: Eddie James Signed-off-by: Andrew Jeffery

serial: Introduce UPSTAT_SYNC_FIFO for synchronised FIFOs

2018-04-05T13:18:49+00:00

This change adds a flag to indicate that a UART is has an external means of synchronising its FIFO, without needing CTSRTS or XON/XOFF. This allows us to use the throttle/unthrottle callbacks, without having to claim other methods of flow control. OpenBMC-Staging-Count: 1 Signed-off-by: Jeremy Kerr Tested-by: Eddie James Signed-off-by: Andrew Jeffery

serial: expose buf_overrun count through proc interface

2018-04-05T13:15:48+00:00

The buf_overrun count is only every written, and not exposed to userspace anywhere. This means that dropped characters due to flip buffer overruns are never visible to userspace. The /proc/tty/driver/serial file exports a bunch of metrics (including hardware overruns) already, so add the buf_overrun (as "bo:") to this file. Signed-off-by: Jeremy Kerr Tested-by: Eddie James (cherry picked from commit 4f794097797f551917b68797e39f25fcb17d5b3a) Signed-off-by: Andrew Jeffery

Merge tag 'v4.13.16' into dev-4.13

2017-11-28T07:41:55+00:00

This is the 4.13.16 stable release

serial: 8250_fintek: Fix finding base_port with activated SuperIO

2017-11-24T07:35:58+00:00

commit fd97e66c5529046e989a0879c3bb58fddb592c71 upstream. The SuperIO will be configured at boot time by BIOS, but some BIOS will not deactivate the SuperIO when the end of configuration. It'll lead to mismatch for pdata->base_port in probe_setup_port(). So we'll deactivate all SuperIO before activate special base_port in fintek_8250_enter_key(). Tested on iBASE MI802. Tested-by: Ji-Ze Hong (Peter Hong) Signed-off-by: Ji-Ze Hong (Peter Hong) Reviewd-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

serial: omap: Fix EFR write on RTS deassertion

2017-11-24T07:35:58+00:00

commit 2a71de2f7366fb1aec632116d0549ec56d6a3940 upstream. Commit 348f9bb31c56 ("serial: omap: Fix RTS handling") sought to enable auto RTS upon manual RTS assertion and disable it on deassertion. However it seems the latter was done incorrectly, it clears all bits in the Extended Features Register *except* auto RTS. Fixes: 348f9bb31c56 ("serial: omap: Fix RTS handling") Cc: Peter Hurley Signed-off-by: Lukas Wunner Signed-off-by: Greg Kroah-Hartman

drivers/serial: Do not leave sysfs group in case of error in aspeed_vuart_probe()

2017-10-09T07:00:39+00:00

There are several error handling paths in aspeed_vuart_probe(), where sysfs group is left unremoved. The patch fixes them. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov Signed-off-by: Greg Kroah-Hartman (cherry picked from commit cbafe9d5c346735d6ac5d5c905fd9c215fbbb941) Signed-off-by: Joel Stanley