linux/drivers/tty/serial
Siftar, Gabe 57c3686842 tty/serial: atmel_serial: fix RS485 half-duplex problem
On our custom board, we are using RS485 in half-duplex mode on an AT91SAM9G45.
SER_RS485_RX_DURING_TX is not set as we do not want to receive the data we
transmit (our transceiver will receive transmitted data).
Although the current driver attempts to disable and enable the receiver at the
appropriate points, incoming data is still loaded into the receive register
causing our code to receive the very last byte that was sent once the receiver
is enabled.

I ran this by Atmel support and they wrote: "The issue comes from the fact
that you disable the PDC/DMA Reception and not the USART Reception channel. In
your case, the[n] you will still receive data into the USART_RHR register, and
maybe you [h]ave the overrun flag set. So please disable the USART reception
channel."

The following patch should force the driver to enable/disable the receiver via
RXEN/RXDIS fields of the USART control register. It fixed the issue I was
having.

Signed-off-by: Gabe Siftar <gabe.siftar@getingeusa.com>
[nicolas.ferre@atmel.com: slightly modify commit message]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-09 10:30:39 -07:00
..
8250 Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
cpm_uart
jsm
21285.c Disintegrate asm/system.h for ARM 2012-03-28 18:30:01 +01:00
68328serial.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
68328serial.h
altera_jtaguart.c
altera_uart.c tty: serial: altera_uart: Check for NULL platform_data in probe. 2012-04-09 10:30:39 -07:00
amba-pl010.c
amba-pl011.c serial: PL011: move interrupt clearing 2012-04-06 14:04:33 -07:00
apbuart.c
apbuart.h
ar933x_uart.c
atmel_serial.c tty/serial: atmel_serial: fix RS485 half-duplex problem 2012-04-09 10:30:39 -07:00
bcm63xx_uart.c
bfin_sport_uart.c
bfin_sport_uart.h
bfin_uart.c serial: bfin-uart: Don't access tty circular buffer in TX DMA interrupt after it is reset. 2012-03-13 14:33:39 -07:00
clps711x.c
crisv10.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
crisv10.h
dz.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
dz.h
efm32-uart.c
icom.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
icom.h
ifx6x60.c TTY: remove re-assignments to tty_driver members 2012-03-08 11:37:58 -08:00
ifx6x60.h
imx.c serial: imx: add clk_prepare/clk_unprepare 2012-02-01 14:29:31 +01:00
ioc3_serial.c
ioc4_serial.c TTY: remove serialP.h inclusion from some files 2012-03-08 11:47:02 -08:00
ip22zilog.c
ip22zilog.h
Kconfig Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2012-03-21 18:55:10 -07:00
kgdboc.c
lantiq.c
m32r_sio_reg.h m32r: relocate drivers back out of 8250 dir 2012-02-08 15:04:32 -08:00
m32r_sio.c TTY: remove serialP.h inclusion from some files 2012-03-08 11:47:02 -08:00
m32r_sio.h TTY: serial, include pci.h in m32r_sio 2012-03-08 11:47:02 -08:00
Makefile Merge tag 'tty-3.3-rc3' tty-next 2012-02-10 10:25:27 -08:00
max3100.c
max3107.c
max3107.h
mcf.c
mfd.c
mpc52xx_uart.c mpc5200b/uart: select more tolerant uart prescaler on low baudrates 2012-03-08 13:15:50 -08:00
mpsc.c
mrst_max3110.c
mrst_max3110.h
msm_serial_hs.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
msm_serial.c
msm_serial.h
msm_smd_tty.c TTY: remove re-assignments to tty_driver members 2012-03-08 11:37:58 -08:00
mux.c tty/serial/mux.c: linux/tty.h included twice 2012-02-24 13:50:45 -08:00
mxs-auart.c
netx-serial.c
nwpserial.c
of_serial.c
omap-serial.c omap-serial: Fix the error handling in the omap_serial probe 2012-04-09 10:30:38 -07:00
pch_uart.c Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma 2012-03-29 15:34:57 -07:00
pmac_zilog.c serial: Kill off NO_IRQ 2012-01-26 17:14:50 -08:00
pmac_zilog.h
pnx8xxx_uart.c
pxa.c ARM: device tree work 2012-03-27 16:47:35 -07:00
sa1100.c ARM: 7342/2: sa1100: prepare for sparse irq conversion 2012-03-25 23:57:20 +01:00
samsung.c serial: samsung: fix s3c2442 platform data 2012-02-24 13:50:46 -08:00
samsung.h
sb1250-duart.c
sc26xx.c
serial_core.c TTY: remove re-assignments to tty_driver members 2012-03-08 11:37:58 -08:00
serial_ks8695.c
serial_txx9.c
sh-sci.c SuperH updates for 3.4 merge window 2012-03-30 00:09:17 -07:00
sh-sci.h
sirfsoc_uart.c pinctrl: API changes to support multiple states per device 2012-03-05 11:22:59 +01:00
sirfsoc_uart.h serial/sirf: fixup for changes to pin control 2012-02-22 17:59:12 +01:00
sn_console.c Miscellaneous Itanium patches 2012-03-23 17:19:37 -07:00
suncore.c tty: sparc: rename drivers/tty/serial/suncore.h -> include/linux/sunserialcore.h 2012-02-10 10:44:35 -08:00
sunhv.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
sunsab.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
sunsab.h
sunsu.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
sunzilog.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
sunzilog.h
timbuart.c
timbuart.h
uartlite.c
ucc_uart.c serial: Kill off NO_IRQ 2012-01-26 17:14:50 -08:00
vr41xx_siu.c serial: Kill off NO_IRQ 2012-01-26 17:14:50 -08:00
vt8500_serial.c tty: serial: vt8500: fix annotations for probe/remove 2012-03-12 10:21:55 -07:00
xilinx_uartps.c
zs.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
zs.h