linux-kernel - Re: [PATCH 6/6 v3] regmap: Incorporate the regcache core into regmap

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Message-ID: <4E721784.90302@metafoo.de>
Date:	Thu, 15 Sep 2011 17:19:32 +0200
From:	Lars-Peter Clausen <lars@...afoo.de>
To:	Dimitris Papastamos <dp@...nsource.wolfsonmicro.com>
CC:	linux-kernel@...r.kernel.org,
	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Liam Girdwood <lrg@...com>,
	Graeme Gregory <gg@...mlogic.co.uk>,
	Samuel Oritz <sameo@...ux.intel.com>
Subject: Re: [PATCH 6/6 v3] regmap: Incorporate the regcache core into regmap

> [...]
> @@ -321,6 +333,18 @@ int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
>  
>  	mutex_lock(&map->lock);
>  
> +	if (!map->cache_bypass) {
> +		ret = regcache_write(map, reg, val);
> +		if (ret < 0) {
> +			mutex_unlock(&map->lock);
> +			return ret;
> +		}
> +		if (map->cache_only) {
> +			mutex_unlock(&map->lock);
> +			return 0;
> +		}
> +	}
> +

Would it make sense to move this into _regmap_write ? In that case the code
wouldn't have to be duplicated in regmap_update_bits and as a bonus it wouldn't
have to deal with the mutex either.

>  	ret = _regmap_write(map, reg, val);
>  
>  	mutex_unlock(&map->lock);
> @@ -422,6 +446,14 @@ int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
>  
>  	mutex_lock(&map->lock);
>  
> +	if (!map->cache_bypass) {
> +		ret = regcache_read(map, reg, val);
> +		if (!ret) {
> +			mutex_unlock(&map->lock);
> +			return 0;
> +		}

So in case regmap_readable is not true for this register regcache_read will
return -EIO and we'll fallback to an uncached read. This doesn't make sense in
my opinion. Or what are the except semantics regmap_readable supposed to be?

> +	}
> +
>  	ret = _regmap_read(map, reg, val);
>  
>  	mutex_unlock(&map->lock);

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