Tests:SCIF-FIFO

This document describes how to test FIFO behavior for the Renesas SCIF, SCIFA, SCIFB, and HSCIF serial ports.

Kernel Version and Configuration

 * arm32: shmobile_defconfig (you may want to enable CONFIG_CGROUPS)
 * arm64: defconfig

By default, serial port DMA is disabled. You can test either with DMA enabled: CONFIG_SERIAL_SH_SCI_DMA=y or disabled:
 * 1) CONFIG_SERIAL_SH_SCI_DMA is not set

Koelsch

 * For testing transfers between SCIF3 and SCIFA5:
 * Connect SCIF3 TXD (EXIO Connector C pin 38) to SCIFA5 RXD (EXIO Connector C pin 39)
 * Connect SCIF3 RXD (EXIO Connector C pin 40) to SCIFA5 TXD (EXIO Connector C pin 37)
 * For testing transfers between SCIFB0 and HSCIF1:
 * Connect SCIFB0 TXD (EXIO Connector A pin 60) to HSCIF1 RXD (EXIO Connector A pin 72)
 * Connect SCIFB0 RXD (EXIO Connector A pin 66) to HSCIF1 TXD (EXIO Connector A pin 53)

Salvator-X

 * For testing transfers between SCIF3 and HSCIF3:
 * Connect SCIF3 TXD (EXIO Connect D pin 21) to HSCIF3 RXD (EXIO Connect D pin 28)
 * Connect SCIF3 RXD (EXIO Connect D pin 27) to HSCIF3 TXD (EXIO Connect D pin 30)

Koelsch
Load all needed DT overlays: overlay add r8a7791-koelsch-exio-c-scif3.dtbo \ r8a7791-koelsch-exio-c-scifa5-c.dtbo \ r8a7791-koelsch-exio-a-scifb0.dtbo \ r8a7791-koelsch-exio-a-hscif1.dtbo

Set up a few convenience macros: scif3=/dev/ttySC3 scifa5=/dev/ttySC11 scifb0=/dev/ttySC12 hscif1=/dev/ttySC16

Test transfers from HSCIF1 to SCIFB0: fifotest $hscif1 $scifb0 -s 1000000 -n 100

Test transfers from SCIFB0 to HSCIF1: fifotest $scifb0 $hscif1 -s 1000000 -n 100

Test transfers from SCIF3 to SCIFA5: fifotest $scif3 $scifa5 -s 1000000 -n 100

Test transfers from SCIFA5 to SCIF3: fifotest $scifa5 $scif3 -s 1000000 -n 100

Expected output for all four tests above (after ca. 12 seconds): MSG: 100, TX: 55208 bytes, RX: 25932 bytes

Salvator-X
SCIF3 and HSCIF3 are already enabled by r8a7795-salvator-x.dts in renesas-drivers. If you use a different tree, you have to make sure the right overlays have been loaded: overlay add r8a7795-salvator-x-exio-d-scif3.dtbo \ r8a7795-salvator-x-exio-d-hscif3.dtbo

Set up a few convenience macros: scif3=/dev/ttySC2 hscif3=/dev/ttySC3

Test transfers from SCIF3 to HSCIF3: fifotest $scif3 $hscif3 -s 1000000 -n 100

Test transfers from HSCIF3 to SCIF3: fifotest $hscif3 $scif3 -s 1000000 -n 100

Expected output for all two tests above (after ca. 12 seconds): MSG: 100, TX: 55208 bytes, RX: 25932 bytes

Linux Kernel Source Tree

 * Git repository: git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git
 * Branches:
 * renesas-drivers-2016-05-17-v4.6 (shows failures)
 * topic/scif-fifo-v1 (fix for the above)
 * renesas-drivers-2016-05-31-v4.7-rc1 (shows success)

Note: The DT overlays are not included in above source trees, so you have to merge the 'renesas-overlays' branch yourself to test on Koelsch. Please see R-Car/DT-Overlays for more information about using DT overlays.

Hence for now I'm providing the following two branches, containing all prerequisites:
 * fifotest-fail (shows failures)
 * fifotest-ok (fixed)

Test Software

 * https://github.com/geertu/fifotest
 * https://github.com/geertu/sertest (for serial link integrity)

Samtec QTE Breakout Adapters

 * Samtec-Breakout-Adapters

Udev rules
If you want to refer to serial ports by their hardware name (e.g. "/dev/scifa5"), you can use the following udev rules:

ENV{DEVNAME}=="/dev/ttySC0", SYMLINK+="scif0" ENV{DEVNAME}=="/dev/ttySC1", SYMLINK+="scif1" ENV{DEVNAME}=="/dev/ttySC2", SYMLINK+="scif2" ENV{DEVNAME}=="/dev/ttySC3", SYMLINK+="scif3" ENV{DEVNAME}=="/dev/ttySC4", SYMLINK+="scif4" ENV{DEVNAME}=="/dev/ttySC5", SYMLINK+="scif5"
 * "/etc/udev/rules.d/99-scif.rules" on Koelsch:

ENV{DEVNAME}=="/dev/ttySC6", SYMLINK+="scifa0" ENV{DEVNAME}=="/dev/ttySC7", SYMLINK+="scifa1" ENV{DEVNAME}=="/dev/ttySC8", SYMLINK+="scifa2" ENV{DEVNAME}=="/dev/ttySC9", SYMLINK+="scifa3" ENV{DEVNAME}=="/dev/ttySC10", SYMLINK+="scifa4" ENV{DEVNAME}=="/dev/ttySC11", SYMLINK+="scifa5"

ENV{DEVNAME}=="/dev/ttySC12", SYMLINK+="scifb0" ENV{DEVNAME}=="/dev/ttySC13", SYMLINK+="scifb1" ENV{DEVNAME}=="/dev/ttySC14", SYMLINK+="scifb2"

ENV{DEVNAME}=="/dev/ttySC15", SYMLINK+="hscif0" ENV{DEVNAME}=="/dev/ttySC16", SYMLINK+="hscif1" ENV{DEVNAME}=="/dev/ttySC17", SYMLINK+="hscif2"

ENV{DEVNAME}=="/dev/ttySC0", SYMLINK+="scif2" ENV{DEVNAME}=="/dev/ttySC1", SYMLINK+="scif1" ENV{DEVNAME}=="/dev/ttySC2", SYMLINK+="scif3" ENV{DEVNAME}=="/dev/ttySC3", SYMLINK+="hscif3" ENV{DEVNAME}=="/dev/ttySC4", SYMLINK+="hscif4"
 * "/etc/udev/rules.d/99-scif.rules" on Salvator-X: