linux-kernel - Re: [PATCH 1/2] regmap: cache: Fix regcache_sync

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Date:	Wed, 27 Aug 2014 12:58:19 +0100
From:	Mark Brown <broonie@...nel.org>
To:	Jarkko Nikula <jarkko.nikula@...ux.intel.com>
Cc:	alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
	Liam Girdwood <lgirdwood@...il.com>
Subject: Re: [PATCH 1/2] regmap: cache: Fix regcache_sync_block for
 non-autoincrementing devices

On Tue, Aug 26, 2014 at 05:03:12PM +0300, Jarkko Nikula wrote:
> Commit 75a5f89f635c ("regmap: cache: Write consecutive registers in a single
> block write") expected that autoincrementing writes are supported if
> hardware has a register format which can support raw writes.
> 
> This is not necessarily true and thus for instance rbtree sync can fail when
> there is need to sync multiple consecutive registers but block write to
> device fails due not supported autoincrementing writes.
> 
> Fix this by spliting raw block sync to series of single register writes for
> devices that don't support autoincrementing writes.

This seems like the wrong place for this - we already have a one
register at a time mechanism for syncing the registers, making the block
write scheme able to do it as well is rather missing the point.  Better
to move the check into sync_block() instead.

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