Re: [RFC][PATCH] regmap: make REGCACHE_NONE maps return error on regcache_sync

From: Nariman Poushin
Date: Fri May 08 2015 - 06:35:03 EST


On Fri, May 08, 2015 at 11:20:19AM +0100, Mark Brown wrote:
> On Fri, May 08, 2015 at 10:55:37AM +0100, Nariman Poushin wrote:
> > Signed-off-by: Nariman Poushin <nariman@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> > ---
> > regcache currently causes a BUG_ON if cache_sync/sync_region is
> > called on a map with cache_type REGCACHE_NONE. This is not
> > consistent with the behaviour of regcache_read/write which
> > currently just return -ENOSYS and only throws a BUG_ON if
> > the cache_type is something that _should_ have cache ops,
> > but doesn't. Sure your device might not work, it but doesn't
> > seem right to panic the kernel. The other option I suppose
> > is to change it to a WARN_ON.
>
> Please submit patches in the format covered in SubmittingPatches, the
> changelog goes before the signoff.
>

Will do, apologies.

> The reason this is so loud is that while it's reasonable that generic
> code could end up triggering a write it's difficult to see any way in
> which a sync could be triggered on a device without a cache without it
> being an obvious bug. Since people frequently don't bother checking
> return codes loud log messages are our only real way of reporting this,
> given where syncs tend to happen it's not likely to happen in an obscure
> code path that won't get seen.

Fair enough, that makes sense.

Thanks
Nariman
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