linux-kernel - Re: regcache_sync() errors for read-only registers cache

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Date:	Tue, 3 Mar 2015 09:09:29 +0000
From:	Mark Brown <broonie@...nel.org>
To:	Takashi Iwai <tiwai@...e.de>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: regcache_sync() errors for read-only registers cache

On Mon, Mar 02, 2015 at 08:15:23PM +0100, Takashi Iwai wrote:
> Mark Brown wrote:

> > Please don't bury patches in the middle of mails, that just means that
> > if the patch is useful it's painful to apply.

> The --scissors option of git am is your friend.

That's still pain.

> > Your patch seems fine but
> > can you please resend in a directly applyable format unless something in
> > the below indicates against that...

> Hm, so do you think that my patch is the best way to fix?  I wasn't
> sure about it, that's why I wrote in that style.

Well, it's either that or adding the values read back from the chip to
the defaults.

> > > Also, _regmap_write() itself calls again regmap_writeable(), so it's
> > > superfluous.  Alternatively, we may check -EIO from _regmap_write()
> > > and treat as a special case not to show the error.  Or, add a
> > > parameter to skip regmap_writeable() call.

> > I'm sorry but I can't parse the above - what is "it" in this context?

> regmap_wrietable() call in _regmap_write().

It's superfluous with respect to what?  Still a bit confused, sorry.

> > Silently ignoring -EIO from the physical register write sounds like a
> > very bad idea though, that seems likely to discard actual errors.

> Right, in that case, a special error code might be used.  But this
> sounds like an overkill, too.

It also sounds like it's heading towards the complex and fragile.

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