Message-ID: <20170511104625.GF22134@linaro.org>
Date:   Thu, 11 May 2017 19:46:27 +0900
From:   AKASHI Takahiro <takahiro.akashi@...aro.org>
To:     "Luis R. Rodriguez" <mcgrof@...nel.org>
Cc:     gregkh@...uxfoundation.org, wagi@...om.org, dwmw2@...radead.org,
        rafal@...ecki.pl, arend.vanspriel@...adcom.com, rjw@...ysocki.net,
        yi1.li@...ux.intel.com, atull@...nsource.altera.com,
        moritz.fischer@...us.com, pmladek@...e.com,
        johannes.berg@...el.com, emmanuel.grumbach@...el.com,
        luciano.coelho@...el.com, kvalo@...eaurora.org, luto@...nel.org,
        dhowells@...hat.com, pjones@...hat.com,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v6 3/5] test: add new driver_data load tester

Luis,

On Fri, Apr 28, 2017 at 03:45:35AM +0200, Luis R. Rodriguez wrote:
> > > +To test an async call one could do::
> > > +
> > > +        echo anything > /lib/firmware/test-driver_data.bin
> > 
> > Your current shell script doesn't search for the firmware in
> > /lib/firmware unless you explicitly specify $FWPATH.
> 
> This is true but that is the *test* shell script, and it purposely avoids the
> existing firmware path to avoid overriding dummy test files on the production
> path. So the above still stands as it is not using the test shell script
> driver_data.sh.
> 
> I'll add a note:
> 
> """
> Note that driver_data.sh uses its own temporary custom path for creating and    
> looking for driver data files, it does this to not overwrite any production     
> files you might have which may share the same names used by the test shell      
> script driver_data.sh. If you are not using the driver_data.sh script your      
> default path will be used. 
> """

That looks fine, but I think we'd better change the line:

> > > +        echo anything > /lib/firmware/test-driver_data.bin

since it is just incorrect as far as driver_data.sh goes.

> > > diff --git a/lib/test_driver_data.c b/lib/test_driver_data.c
> > > new file mode 100644
> > > index 000000000000..11175a3b9f0a
> > > --- /dev/null
> > > +++ b/lib/test_driver_data.c
> > > @@ -0,0 +1,1272 @@
> > > +/*
> > > + * Driver data test interface
> > > + *
> > > + * Copyright (C) 2017 Luis R. Rodriguez <mcgrof@...nel.org>
> > > + *
> > > + * This program is free software; you can redistribute it and/or modify it
> > > + * under the terms of copyleft-next (version 0.3.1 or later) as published
> > > + * at http://copyleft-next.org/.
> > 
> > Is this compatible with GPLv2 for kernel modules?
> 
> Yes, I went through all possible channels to vet for this, for details refer
> to the thread which explains this [0] where the first attempt was to actually add
> the license to the list of compatible licenses. So Linus' preference is to use
> MODULE_LICENSE("GPL") rather.
> 
> [0] https://lkml.kernel.org/r/CA+55aFyhxcvD+q7tp+-yrSFDKfR0mOHgyEAe=f_94aKLsOu0Og@mail.gmail.com

Thank you for this heads-up.
According to Linus' comment, he seems to expect an explicit GPL license
term to be in the beginning of the file, and then if you want, an additional
license to be added, quote "if you want to dual-license it, just put something
like "or, at your option, copyleft-next" in the comment at the top."


> > > diff --git a/tools/testing/selftests/firmware/driver_data.sh b/tools/testing/selftests/firmware/driver_data.sh
> 
> ...
> 
> > > +TEST_NAME="driver_data"
> > > +TEST_DRIVER="test_${TEST_NAME}"
> > > +TEST_DIR=$(dirname $0)
> > > +
> > > +# This represents
> > > +#
> > > +# TEST_ID:TEST_COUNT:ENABLED
> > > +#
> > > +# TEST_ID: is the test id number
> > > +# TEST_COUNT: number of times we should run the test
> > > +# ENABLED: 1 if enabled, 0 otherwise
> > > +#
> > > +# Once these are enabled please leave them as-is. Write your own test,
> > > +# we have tons of space.
> > > +ALL_TESTS="0001:3:1"
> > > +ALL_TESTS="$ALL_TESTS 0002:3:1"
> > > +ALL_TESTS="$ALL_TESTS 0003:3:1"
> > > +ALL_TESTS="$ALL_TESTS 0004:10:1"
> > > +ALL_TESTS="$ALL_TESTS 0005:10:1"
> > > +ALL_TESTS="$ALL_TESTS 0006:10:1"
> > > +ALL_TESTS="$ALL_TESTS 0007:10:1"
> > > +ALL_TESTS="$ALL_TESTS 0008:10:1"
> > > +ALL_TESTS="$ALL_TESTS 0009:10:1"
> > > +ALL_TESTS="$ALL_TESTS 0010:10:1"
> > > +ALL_TESTS="$ALL_TESTS 0011:10:1"
> > > +ALL_TESTS="$ALL_TESTS 0012:1:1"
> > > +ALL_TESTS="$ALL_TESTS 0013:1:1"
> > 
> > Do you have good reasons for "the number of times" here?
> 
> Just that 1 was not enough and more than 10 seemed too much. As is the tests

In my opinion, "1," or "2" given the nature of firmware caching, is good
enough, but it's up to you.

BTW, firmware caching is a bit annoying in my signature tests
because caching will bypass the verification checks when we iterates
tests with different conditions.

> are rather simple compared to what we can do given the flexibility in how we
> can perform tests due to the test driver structure, in the future this will
> become more important. But best to just get in the basics before we hammer and
> expand on this a lot. There is also the question of sharing this sort of logic
> with the upper testing layers so that they deal with this and not us
> (tools/testing/selftests/), in that sense all this is just sufficient for us to do
> our own testing for now, but we may and should consider how to get the upper
> layers to deal this for us. But we can address this later.
> 
> > > +# Not yet sure how to automate suspend test well yet.  For now we expect a
> > > +# manual run. If using qemu you can resume a guest using something like the
> > > +# following on the monitor pts.
> > > +# system_wakeupakeup | socat - /dev/pts/7,raw,echo=0,crnl
> > > +#ALL_TESTS="$ALL_TESTS 0014:0:1"
> > > +
> > > +test_modprobe()
> > > +{
> > > +       if [ ! -d $DIR ]; then
> > > +               echo "$0: $DIR not present" >&2
> > > +               echo "You must have the following enabled in your kernel:" >&2
> > > +               cat $TEST_DIR/config >&2
> > > +               exit 1
> > > +       fi
> > > +}
> > > +
> > > +function allow_user_defaults()
> > > +{
> > > +	if [ -z $DEFAULT_NUM_TESTS ]; then
> > > +		DEFAULT_NUM_TESTS=50
> > > +	fi
> > > +
> > > +	if [ -z $FW_SYSFSPATH ]; then
> > > +		FW_SYSFSPATH="/sys/module/firmware_class/parameters/path"
> > > +	fi
> > > +
> > > +	if [ -z $OLD_FWPATH ]; then
> > > +		OLD_FWPATH=$(cat $FW_SYSFSPATH)
> > > +	fi
> > > +
> > > +	if [ -z $FWPATH]; then
> > > +		FWPATH=$(mktemp -d)
> > > +	fi
> > > +
> > > +	if [ -z $DEFAULT_DRIVER_DATA ]; then
> > > +		config_reset
> > > +		DEFAULT_DRIVER_DATA=$(config_get_name)
> > > +	fi
> > > +
> > > +	if [ -z $FW ]; then
> > > +		FW="$FWPATH/$DEFAULT_DRIVER_DATA"
> > > +	fi
> > > +
> > > +	if [ -z $SYS_STATE_PATH ]; then
> > > +		SYS_STATE_PATH="/sys/power/state"
> > > +	fi
> > > +
> > > +	# Set the kernel search path.
> > > +	echo -n "$FWPATH" > $FW_SYSFSPATH
> > > +
> > > +	# This is an unlikely real-world firmware content. :)
> > > +	echo "ABCD0123" >"$FW"
> > 
> > Do you always want to overwrite the firmware even if user explicitly
> > provides it?
> 
> This is a test script so it constructs its own temporary path so it can
> have the confidence to overwrite anything it pleases. So in this case yes.
> Its just as the old firmware test script.

Right, but looking into the script, even if an user supplies a firmware
blob, the script overwrites it unnecessarily.
This may also be inconvenient if I add signature verification tests.
(Not sure though.)

> > > +usage()
> > > +{
> > > +	NUM_TESTS=$(grep -o ' ' <<<"$ALL_TESTS" | grep -c .)
> > > +	let NUM_TESTS=$NUM_TESTS+1
> > > +	MAX_TEST=$(printf "%04d\n" $NUM_TESTS)
> > > +	echo "Usage: $0 [ -t <4-number-digit> ] | [ -w <4-number-digit> ] |"
> > > +	echo "		 [ -s <4-number-digit> ] | [ -c <4-number-digit> <test- count>"
> > > +	echo "           [ all ] [ -h | --help ] [ -l ]"
> > > +	echo ""
> > > +	echo "Valid tests: 0001-$MAX_TEST"
> > > +	echo ""
> > > +	echo "    all     Runs all tests (default)"
> > > +	echo "    -t      Run test ID the number amount of times is recommended"
> > > +	echo "    -w      Watch test ID run until it runs into an error"
> > > +	echo "    -c      Run test ID once"
> > 
> >                -> -s
> > 
> > > +	echo "    -s      Run test ID x test-count number of times"
> > 
> >                -> -c
> 
> Good thing you highlighted these, I had them flipped, -s was for single run
> and -c was for test-count number of times.
>
> > If you make the second parameter optional, you don't need
> > -t nor -s:
> >         driver_data.sh -c 0004     ; recommended times
> >         driver_data.sh -c 0004 1   ; only once
> >         driver_data.sh -c 0004 100 ; as many times as you want
> 
> True but I prefer having short-hand notations as well.

Okay, up to you.

> PS. In the future I'd highly appreciate if you can trim your responses
> so you leave only in context enough information to just review the
> criteria you are commenting on, rather than keeping every single line.

Got it.

Thanks,
-Takahiro AKASHI

>   Luis

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