Date: Mon, 01 Jul 2019 16:16:33 +0000 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: Andriy Gapon <avg@FreeBSD.org> Cc: FreeBSD Current <freebsd-current@FreeBSD.org> Subject: Re: i2c bit banging timeout for SCL Message-ID: <92906.1561997793@critter.freebsd.dk> In-Reply-To: <a3538c10-2438-a287-77db-ad390078b274@FreeBSD.org> References: <a3538c10-2438-a287-77db-ad390078b274@FreeBSD.org>
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-------- In message <a3538c10-2438-a287-77db-ad390078b274@FreeBSD.org>, Andriy Gapon writes: >iicbb driver has a hardcoded timeout that defines how long the driver waits for > SCL line to go high after the driver releases it to float. Sometimes slaves >hold the line low until they are ready to continue with the communication. >As a side note, the timeout means that the driver just goes on as if the line >became high. Maybe it should produce an error instead. > >Anyway, I would like to increase the current timeout of 100 x 10us to 1000 x >10us. The rationale is that there are many slave devices, like sensors, that >take about 10 ms to return a result. So, I think that it makes sense to play >nice with such devices by default. > >Probably I'll add a sysctl for that parameter while I'll be there. sysctl or ioctl ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.
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