Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 27 Nov 2020 08:09:38 -0300
From:      "Dr. Rolf Jansen" <freebsd-rj@obsigna.com>
To:        Vladimir Goncharov <freebsd@viruzzz.org>
Cc:        freebsd-arm@freebsd.org
Subject:   Re: User Space GPIO Interrupt programming - GSoC-2018
Message-ID:  <8655AF30-273B-48E7-98CD-007AA1D265F5@obsigna.com>
In-Reply-To: <8d806302-479c-ca34-3fdb-96d27f40e212@viruzzz.org>
References:  <2B01780F-D367-48A3-A827-B479030A496D@obsigna.com> <c55d7f332631b69c3241a60538a6a7b5475d93b9.camel@freebsd.org> <FBEF19B1-0504-4CDF-976C-C50707E06584@obsigna.com> <8d806302-479c-ca34-3fdb-96d27f40e212@viruzzz.org>

next in thread | previous in thread | raw e-mail | index | archive | help
Hello Vladimir,

yes please, I am interested. Please can show us your version of the =
GSoC-2018 diff file?

Best regards

Rolf

> Am 27.11.2020 um 05:02 schrieb Vladimir Goncharov =
<freebsd@viruzzz.org>:
>=20
> Hello Rolf,
>=20
> I have implemented in kernel queue for generated GPIO interrupts with
> timestamps, so now it's possible to catch all events even on busy
> system. It's all for gpio_gsoc2018 code. In result I have no more
> warnings in dmesg. Unfortunately it requires allocating memory on each
> event to store pin number and timestamp. In case of unability =
allocating
> memory it falls back to gpio_gsoc2018 method.
> Does anybody interested in such patches?
>=20
>=20
> 2020-11-27 04:18, Dr. Rolf Jansen =D0=BF=D0=B8=D1=88=D0=B5=D1=82:
>>> Am 26.11.2020 um 16:56 schrieb Ian Lepore <ian@freebsd.org>:
>>>=20
>>> On Tue, 2020-11-24 at 17:14 -0300, Dr. Rolf Jansen wrote:
>>>> Hello
>>>>=20
>>>> Has anything of the GSoC-2018 efforts made it into the current code
>>>> base?
>>>>=20
>>>>=20
>>> =
https://wiki.freebsd.org/SummerOfCode2018Projects/UserSpaceGPIOinterrupts
>>>>=20
>>>> I installed the recent 13.0-CURRENT snapshot (2020-11-19) on a
>>>> BeagleBone Black which was one of the implementation targets of =
said
>>>> project, but when running the test tools, I either see cannot
>>>> read/kevent/poll/aio_read - Operation not supported by device or
>>>> Inappropriate ioctl for device.
>>>>=20
>>>> Perhaps I need to pull the project=C2=B4s changes into the kernel =
by
>>>> myself. However, before this I would like to ask whether it is =
worth
>>>> the effort.
>>>>=20
>>>> Please, can anyone shed some light on this.
>>>>=20
>>>> Best regards
>>>>=20
>>>> Rolf
>>>>=20
>>>=20
>>> I made some time this morning to review the gsoc2018 code.  It turns
>>> out this code is very high quality, nearly ready to commit as-is.  =
The
>>> main thing it needs is some style cleanup in its comment blocks, and
>>> documentation.  I'd be inclined to commit the code first and write =
the
>>> documentation over the next little while and commit it separately.
>>>=20
>>> If you'd like to give it a try, here's a diff that should apply and
>>> build cleanly on freebsd 12 or 13:
>>>=20
>>> https://people.freebsd.org/~ian/gpio_gsoc2018.diff
>>>=20
>>> While there isn't any documentation yet, there is a test program (I
>>> haven't run it yet) that demonstrates all the features:
>>>=20
>>> =
https://github.com/ckraemer/gsoc2018-utils/blob/master/src/gpioc_intr_test=
.c
>>>=20
>>> Right now the code will let you block waiting for a pin-change event
>>> using select(), poll() or kevents, or to be notified via SIGIO, but
>>> after being notified that something happened, you still have to call
>>> read() to see which pin changed.  I think if the pin changes state
>>> multiple times between calls to read(), you'll lose track of some
>>> changes (I'm not positive of that, I don't understand the kevent =
stuff
>>> well).
>>>=20
>>> I'd like to add some features so that you can configure it to track =
pin
>>> changes in counting-mode and timestamping-mode.  In counting mode, =
when
>>> you do a read() you would get back a pair of values, the pin number =
and
>>> how many times its interrupt fired since the last read.  In
>>> timestamping mode, every read would return a pin number and an
>>> associated timespec giving the exact time the interrupt happened =
(there
>>> would need to be a way to configure how many events it could buffer,
>>> but I think even allowing a thousand buffered events would only use =
a
>>> few kbytes of memory).
>>=20
>> I got it working as well, please see my other post from yesterday. I =
used gpioc_intr_test.c.
>>=20
>> I see hundreds of warning messages when I press the test button a few =
times. May these warnings be safely ignored. The kernel module of Oskar =
Holmund works quite nice as well (for what I need), and with that one, I =
don=E2=80=99t see warnings.
>>=20
>> The counting- and timestamping-mode for sure would be very useful. =
Perhaps by implementing this, there won=E2=80=99t be no unhandled =
interrupts anymore, and hence there won=E2=80=99t be any warnings =
either.
>>=20
>> Best regards
>>=20
>> Rolf
>>=20
>>=20
> _______________________________________________
> freebsd-arm@freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-arm
> To unsubscribe, send any mail to "freebsd-arm-unsubscribe@freebsd.org"



Dr. Rolf Jansen
- -
Rua Reginaldo de Lima, 98
Parque S=C3=A3o Diogo
09732-550, S=C3=A3o Bernardo do Campo
S=C3=A3o Paulo - Brazil

Phone:	0055-11/4317-0974
Mobile:	0055-11/9 8141-1465
E-Mail:	rj@obsigna.com <mailto:rj@obsigna.com>
BLog:	obsigna.com <http://obsigna.com/>;



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?8655AF30-273B-48E7-98CD-007AA1D265F5>