[LTP] [PATCH v2] uart: add uart testcase in kernel device-drivers

[Cyril Hrubis]

Hi!
>  runtest/kernel_misc                           |  6 ++
>  testcases/kernel/device-drivers/Makefile      |  1 +
>  testcases/kernel/device-drivers/uart/Makefile | 10 +++
>  .../kernel/device-drivers/uart/serialcheck.sh | 68 +++++++++++++++++++
>  4 files changed, 85 insertions(+)
>  create mode 100644 testcases/kernel/device-drivers/uart/Makefile
>  create mode 100755 testcases/kernel/device-drivers/uart/serialcheck.sh
> 
> diff --git a/runtest/kernel_misc b/runtest/kernel_misc
> index 7937c7bbf..7a077b23b 100644
> --- a/runtest/kernel_misc
> +++ b/runtest/kernel_misc
> @@ -13,3 +13,9 @@ zram01 zram01.sh
>  zram02 zram02.sh
>  zram03 zram03
>  umip_basic_test umip_basic_test
> +# uart test in loopback mode
> +uart_9600_k serialcheck.sh 9600 5 k
> +uart_19200_k serialcheck.sh 19200 5 k
> +uart_38400_k serialcheck.sh 38400 5 k
> +uart_57600_k  serialcheck.sh 57600 5 k
> +uart_115200_k serialcheck.sh 115200 5 k
> diff --git a/testcases/kernel/device-drivers/Makefile b/testcases/kernel/device-drivers/Makefile
> index 55e0d25a0..a214f211b 100644
> --- a/testcases/kernel/device-drivers/Makefile
> +++ b/testcases/kernel/device-drivers/Makefile
> @@ -27,6 +27,7 @@ SUBDIRS		:= acpi \
>  		   rtc \
>  		   tbio \
>  		   uaccess \
> +		   uart \
>  		   zram
>  
>  include $(top_srcdir)/include/mk/generic_trunk_target.mk
> diff --git a/testcases/kernel/device-drivers/uart/Makefile b/testcases/kernel/device-drivers/uart/Makefile
> new file mode 100644
> index 000000000..2e4781a6b
> --- /dev/null
> +++ b/testcases/kernel/device-drivers/uart/Makefile
> @@ -0,0 +1,10 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +# Copyright (c) 2014-2015 Oracle and/or its affiliates. All Rights Reserved.
> +
> +top_srcdir	?= ../../../..
> +include $(top_srcdir)/include/mk/testcases.mk
> +
> +INSTALL_TARGETS		:= *.sh
> +
> +include $(top_srcdir)/include/mk/generic_leaf_target.mk
> diff --git a/testcases/kernel/device-drivers/uart/serialcheck.sh b/testcases/kernel/device-drivers/uart/serialcheck.sh
> new file mode 100755
> index 000000000..afdc9212f
> --- /dev/null
> +++ b/testcases/kernel/device-drivers/uart/serialcheck.sh
> @@ -0,0 +1,68 @@
> +#!/bin/sh
> +###############################################################################
> +#
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +# Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
> +# Copyright (C) 2019, Unisoc Communications Inc.
> +#
> +# Test UART ports using git://git.breakpoint.cc/bigeasy/serialcheck.git
> +#
> +###############################################################################
> +
> +TST_TESTFUNC=do_test
> +TST_POS_ARGS=3
> +TST_USAGE=usage
> +TST_NEEDS_ROOT=1
> +TST_NEEDS_CMDS="serialcheck"
> +TST_NEEDS_CMDS="lsof"
> +TST_NEEDS_CMDS="dd"
> +TST_NEEDS_TMPDIR=1
> +
> +. tst_test.sh
> +
> +usage()
> +{
> +    echo "usage: ./${0} [-r UART_RATE] [-l LOOPS] [-h|k to enable HW flow control or loopback]"
> +    exit 1
> +}
> +
> +UART_RATE=$1
> +UART_LOOPS=$2
> +UART_HWFLOW=$3
> +
> +create_test_file()
> +{
> +    temp_test_file=`mktemp`
> +    dd if=/dev/urandom of=$temp_test_file count=1 bs=$((UART_RATE / 2))

Once the test creates temporary directory by TST_NEEDS_TMPDIR there is
no need for a mktemp anymore. The test runs with PWD pointing to a
unique temporary directory at that point.

> +}
> +
> +test_serial()
> +{
> +    create_test_file
> +    { sleep 1; serialcheck -b $UART_RATE -d $1 -f $temp_test_file -l $UART_LOOPS -m t -${UART_HWFLOW}; }&
> +    PID=$!
> +    serialcheck -b $UART_RATE -d $1 -f $temp_test_file -l $UART_LOOPS -m r -${UART_HWFLOW}

What do you need the sleep 1 for?

Tests should synchronize processes properly with locks instead of doing
random sleep and hoping for the best.

> +    if [ $? ];  then
> +        kill -- -$PID 2>/dev/null
> +        tst_res TFAIL "uart test failed"
> +    else
> +        tst_res TPASS "uart test passed"
> +    fi
> +    rm $temp_test_file
> +}
> +
> +do_test()
> +{
> +    for i in /sys/class/tty/*/uartclk ;do
> +        PORT=`echo $i |cut -d '/' -f 5`
> +        # Activate port in case it will be initialized only when startup
> +        echo "UART TESTING">${PORT} 2>/dev/null
> +        if [ `cat /sys/class/tty/${PORT}/uartclk` -ne 0 ]; then
> +            lsof | grep "/dev/${PORT}" &> /dev/null || PORT_TO_TEST="/dev/${PORT}"
> +            tst_res TINFO "start test on ${PORT_TO_TEST} ${UART_RATE}"
> +            test_serial ${PORT_TO_TEST}
> +        fi
> +    done

This is problematic as well, it expects that all ports that are not
in-use are loopback connected. This is not true in general case, which
means that we cannot add the test to the kernel_misc runtest file as it
is because it will fail on most of the systems out there.

We will have to figure out how to pass which ports are interconnected to
the test somehow, because that is something that only the user who set
up the machine knows.

-- 
Cyril Hrubis
chrubis@suse.cz