Re: [PATCH V8 1/2] i2c/adapter: Add bus recovery infrastructure

[Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>]

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> > Timeout value. I consider I2C a static bus with no hotplugging. So,
> > either we have seen a START bit and know we are inside a transaction or
> > SDA is low because a slave is in an unknown state.
> This is probably true in at least 9 out of 10 cases today. I wonder if
> that will stay as is. Up to you to ignore it. (I promise not to be
> offended.)

If that will be the case somewhen, bus recovery might be a bad idea in
general. Then again, such a setup is the one needing it most, probably
;) But hotplugging I2C is desperatly asking for problems.

> > > > This scl check should not depend on skip_sda_polling, or?
> > > Well right. But note this might also just be a slave doing clock
> > > streching.
> > 
> > Which is a good reason to exit recovery.
> Not necessarily. If a slave hangs and would need say 5 additional clocks
> it still can stretch the 2nd clock cycle.

While unlikely on the bit-level, still true. Need to think about it.

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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