linux-stable.git/drivers/tty/serial, branch v3.14.39

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

2015-04-19T08:11:08+00:00

commit 8e4934c6d6c659e22b1b746af4196683e77ce6ca upstream.

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 
Signed-off-by: Greg Kroah-Hartman

Change email address for 8250_pci

2015-03-26T14:06:53+00:00

commit f2e0ea861117bda073d1d7ffbd3120c07c0d5d34 upstream.

I'm still receiving reports to my email address, so let's point this
at the linux-serial mailing list instead.

Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

tty/serial: at91: fix error handling in atmel_serial_probe()

2015-03-06T22:43:30+00:00

commit 6fbb9bdf0f3fbe23aeff806489791aa876adaffb upstream.

-EDEFER error wasn't handle properly by atmel_serial_probe().
As an example, when atmel_serial_probe() is called for the first time, we pass
the test_and_set_bit() test to check whether the port has already been
initalized. Then we call atmel_init_port(), which may return -EDEFER, possibly
returned before by clk_get(). Consequently atmel_serial_probe() used to return
this error code WITHOUT clearing the port bit in the "atmel_ports_in_use" mask.
When atmel_serial_probe() was called for the second time, it used to fail on
the test_and_set_bit() function then returning -EBUSY.

When atmel_serial_probe() fails, this patch make it clear the port bit in the
"atmel_ports_in_use" mask, if needed, before returning the error code.

Signed-off-by: Cyrille Pitchen 
Acked-by: Nicolas Ferre 
Signed-off-by: Greg Kroah-Hartman

serial: samsung: wait for transfer completion before clock disable

2015-01-16T14:59:32+00:00

commit 1ff383a4c3eda8893ec61b02831826e1b1f46b41 upstream.

This patch adds waiting until transmit buffer and shifter will be empty
before clock disabling.

Without this fix it's possible to have clock disabled while data was
not transmited yet, which causes unproper state of TX line and problems
in following data transfers.

Signed-off-by: Robert Baldyga 
Signed-off-by: Greg Kroah-Hartman

serial: Fix divide-by-zero fault in uart_get_divisor()

2014-11-14T17:00:02+00:00

commit 547039ec502076e60034eeb79611df3433a99b7d upstream.

uart_get_baud_rate() will return baud == 0 if the max rate is set
to the "magic" 38400 rate and the SPD_* flags are also specified.
On the first iteration, if the current baud rate is higher than the
max, the baud rate is clamped at the max (which in the degenerate
case is 38400). On the second iteration, the now-"magic" 38400 baud
rate selects the possibly higher alternate baud rate indicated by
the SPD_* flag. Since only two loop iterations are performed, the
loop is exited, a kernel WARNING is generated and a baud rate of
0 is returned.

Reproducible with:
 setserial /dev/ttyS0 spd_hi base_baud 38400

Only perform the "magic" 38400 -> SPD_* baud transform on the first
loop iteration, which prevents the degenerate case from recognizing
the clamped baud rate as the "magic" 38400 value.

Reported-by: Robert Święcki 
Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

tty: omap-serial: fix division by zero

2014-10-30T16:38:22+00:00

commit dc3187564e61260f49eceb21a4e7eb5e4428e90a upstream.

If the chosen baud rate is large enough (e.g. 3.5 megabaud), the
calculated n values in serial_omap_is_baud_mode16() may become 0. This
causes a division by zero when calculating the difference between
calculated and desired baud rates. To prevent this, cap the n13 and n16
values on 1.

Division by zero in kernel.
[] (unwind_backtrace) from [] (show_stack+0x10/0x14)
[] (show_stack) from [] (Ldiv0+0x8/0x10)
[] (Ldiv0) from [] (serial_omap_baud_is_mode16+0x4c/0x68)
[] (serial_omap_baud_is_mode16) from [] (serial_omap_set_termios+0x90/0x8d8)
[] (serial_omap_set_termios) from [] (uart_change_speed+0xa4/0xa8)
[] (uart_change_speed) from [] (uart_set_termios+0xa0/0x1fc)
[] (uart_set_termios) from [] (tty_set_termios+0x248/0x2c0)
[] (tty_set_termios) from [] (set_termios+0x248/0x29c)
[] (set_termios) from [] (tty_mode_ioctl+0x1c8/0x4e8)
[] (tty_mode_ioctl) from [] (tty_ioctl+0xa94/0xb18)
[] (tty_ioctl) from [] (do_vfs_ioctl+0x4a0/0x560)
[] (do_vfs_ioctl) from [] (SyS_ioctl+0x4c/0x74)
[] (SyS_ioctl) from [] (ret_fast_syscall+0x0/0x30)

Signed-off-by: Frans Klaver 
Signed-off-by: Greg Kroah-Hartman

serial: 8250: Add Quark X1000 to 8250_pci.c

2014-10-15T06:36:43+00:00

commit 1ede7dcca3c4fa15a518ab0473126f9c3e621e4c upstream.

Quark X1000 contains two designware derived 8250 serial ports.
Each port has a unique PCI configuration space consisting of
BAR0:UART BAR1:DMA respectively.

Unlike the standard 8250 the register width is 32 bits for RHR,IER etc
The Quark UART has a fundamental clock @ 44.2368 MHz allowing for a
bitrate of up to about 2.76 megabits per second.

This patch enables standard 8250 mode

Signed-off-by: Bryan O'Donoghue 
Reviewed-by: Heikki Krogerus 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_dma: check the result of TX buffer mapping

2014-10-05T21:52:24+00:00

commit d4089a332883ad969700aac5dd4dd5f1c4fee825 upstream.

Using dma_mapping_error() to make sure the mapping did not
fail.

Signed-off-by: Heikki Krogerus 
Cc: "Petallo, MauriceX R" 
Signed-off-by: Greg Kroah-Hartman

serial: core: Preserve termios c_cflag for console resume

2014-09-05T23:34:14+00:00

commit ae84db9661cafc63d179e1d985a2c5b841ff0ac4 upstream.

When a tty is opened for the serial console, the termios c_cflag
settings are inherited from the console line settings.
However, if the tty is subsequently closed, the termios settings
are lost. This results in a garbled console if the console is later
suspended and resumed.

Preserve the termios c_cflag for the serial console when the tty
is shutdown; this reflects the most recent line settings.

Fixes: Bugzilla #69751, 'serial console does not wake from S3'
Reported-by: Valerio Vanni 
Acked-by: Alan Cox 
Signed-off-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

sunsab: Fix detection of BREAK on sunsab serial console

2014-08-14T01:38:26+00:00

[ Upstream commit fe418231b195c205701c0cc550a03f6c9758fd9e ]

Fix detection of BREAK on sunsab serial console: BREAK detection was only
performed when there were also serial characters received simultaneously.
To handle all BREAKs correctly, the check for BREAK and the corresponding
call to uart_handle_break() must also be done if count == 0, therefore
duplicate this code fragment and pull it out of the loop over the received
characters.

Patch applies to 3.16-rc6.

Signed-off-by: Christopher Alexander Tobias Schulze 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman