linux-stable.git/drivers/tty/serial, branch v3.18.22

tty/serial: at91: RS485 mode: 0 is valid for delay_rts_after_send

2015-07-12T14:54:24+00:00

[ Upstream commit 8687634b7908c42eb700e0469e110e02833611d1 ]

In RS485 mode, we may want to set the delay_rts_after_send value to 0.
In the datasheet, the 0 value is said to "disable" the Transmitter Timeguard but
this is exactly the expected behavior if we want no delay...

Moreover, if the value was set to non-zero value by device-tree or earlier
ioctl command, it was impossible to change it back to zero.

Reported-by: Sami Pietikäinen 
Signed-off-by: Nicolas Ferre 
Cc: stable@vger.kernel.org  # 3.2+
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: imx: Fix DMA handling for IDLE condition aborts

2015-07-03T16:34:44+00:00

[ Upstream commit 392bceedb107a3dc1d4287e63d7670d08f702feb ]

The driver configures the IDLE condition to interrupt the SDMA engine.
Since the SDMA UART ROM script doesn't clear the IDLE bit itself, this
caused repeated 1-byte DMA transfers, regardless of available data in the
RX FIFO. Also, when returning due to the IDLE condition, the UART ROM
script already increased its counter, causing residue to be off by one.

This patch clears the IDLE condition to avoid repeated 1-byte DMA transfers
and decreases count by when the DMA transfer was aborted due to the IDLE
condition, fixing serial transfers using DMA on i.MX6Q.

Reported-by: Peter Seiderer 
Signed-off-by: Philipp Zabel 
Tested-by: Fabio Estevam 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250_dw: add support for AMD SOC Carrizo

2015-06-28T17:39:20+00:00

[ Upstream commit 5ef86b74209db33c133b5f18738dd8f3189b63a1 ]

Add ACPI identifier for UART on AMD SOC Carrizo.

Signed-off-by: Ken Xue 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: 8250: add support for ACPI-probed serial port for X-Gene platform

2015-06-28T17:39:20+00:00

[ Upstream commit 5e1aeea52f6a0763e79473b1767401fda88eb7e1 ]

Enable APM X-Gene SoC serial port functionality when using ACPI table to
initialize serial port.

Signed-off-by: Feng Kan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: imx: Fix clearing of receiver overrun flag

2015-06-28T17:39:15+00:00

[ Upstream commit 91555ce9012557b2d621d7b0b6ec694218a2a9bc ]

The writeable bits in the USR2 register are all "write 1 to
clear" so only write the bits that actually should be cleared.

Fixes: f1f836e4209e ("serial: imx: Add Rx Fifo overrun error message")
Signed-off-by: Uwe Kleine-König 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: imx: Enable UCR4_OREN in startup interface

2015-06-28T17:39:15+00:00

[ Upstream commit 6f026d6b7cb6e019b6352ed7fb71497c787fd6d7 ]

Other than enable Receiver Overrun Interrupt Enable (UCR4_OREN)
in start_tx interface, UCR4_OREN should be enabled before enable
of Receiver.

Signed-off-by: Jiada Wang 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

tty/serial: at91: maxburst was missing for dma transfers

2015-05-17T23:12:40+00:00

[ Upstream commit a8d4e01637902311c5643b69a5c80e2805f04054 ]

Maxburst was not set when doing the dma slave configuration. This value
is checked by the recently introduced xdmac. It causes an error when
doing the slave configuration and so prevents from using dma.

Signed-off-by: Ludovic Desroches 
Cc:  # 3.12 and later
Acked-by: Nicolas Ferre 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: xilinx: Use platform_get_irq to get irq description structure

2015-05-17T23:12:38+00:00

[ Upstream commit 5c90c07b98c02198d9777a7c4f3047b0a94bf7ed ]

For systems with CONFIG_SERIAL_OF_PLATFORM=y and device_type =
"serial"; property in DT of_serial.c driver maps and unmaps IRQ (because
driver probe fails). Then a driver is called but irq mapping is not
created that's why driver is failing again in again on request_irq().
Based on this use platform_get_irq() instead of platform_get_resource()
which is doing irq_desc allocation and driver itself can request IRQ.

Fix both xilinx serial drivers in the tree.

Signed-off-by: Michal Simek 
CC: 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

serial: of-serial: Remove device_type = "serial" registration

2015-05-17T23:12:37+00:00

[ Upstream commit 6befa9d883385c580369a2cc9e53fbf329771f6d ]

Do not probe all serial drivers by of_serial.c which are using
device_type = "serial"; property. Only drivers which have valid
compatible strings listed in the driver should be probed.

When PORT_UNKNOWN is setup probe will fail anyway.

Arnd quotation about driver historical background:
"when I wrote that driver initially, the idea was that it would
get used as a stub to hook up all other serial drivers but after
that, the common code learned to create platform devices from DT"

This patch fix the problem with on the system with xilinx_uartps and
16550a where of_serial failed to register for xilinx_uartps and because
of irq_dispose_mapping() removed irq_desc. Then when xilinx_uartps was asking
for irq with request_irq() EINVAL is returned.

Signed-off-by: Michal Simek 
CC: 
Acked-by: Arnd Bergmann 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

tty: serial: fsl_lpuart: clear receive flag on FIFO flush

2015-04-24T21:14:00+00:00

[ Upstream commit 8e4934c6d6c659e22b1b746af4196683e77ce6ca ]

When the receiver was enabled during startup, a character could
have been in the FIFO when the UART get initially used. The
driver configures the (receive) watermark level, and flushes the
FIFO. However, the receive flag (RDRF) could still be set at that
stage (as mentioned in the register description of UARTx_RWFIFO).
This leads to an interrupt which won't be handled properly in
interrupt mode: The receive interrupt function lpuart_rxint checks
the FIFO count, which is 0 at that point (due to the flush
during initialization). The problem does not manifest when using
DMA to receive characters.

Fix this situation by explicitly read the status register, which
leads to clearing of the RDRF flag. Due to the flush just after
the status flag read, a explicit data read is not to required.

Signed-off-by: Stefan Agner 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin