Re: [PATCH 1/2] regmap: Allow installing custom reg_update_bits function
On Thu, Oct 01, 2015 at 08:29:19AM -0400, Jon Ringle wrote:
> On Thu, 1 Oct 2015, Mark Brown wrote:
> > This completely bypasses and therefore breaks the cache infrastructure.
> Right after sending the v2 patch, I realized that calling the
> custom reg_update_bits would only be applicable for registers that are
> marked as volatile. Would the following solution be acceptable (it would
Well, it should still *work* with a cache, though it's certainly true
that it's unlikely to have any performance benefit with cached register
since the read part of the read/modify/write cycle is essentially free
with the cache.
> also simplify the regmap_update_bits in the encx24j600 driver):
> if (regmap_volatile(map, reg) && map->reg_update_bits) {
> return map->reg_update_bits(map->bus_context, reg, mask,
> val, change, force_write);
> The cache state should not matter for volatile registers, right?
Right. I see you've sent a new patch already, I'll reply to that after
I've thought about it a little.
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Re: [PATCH 1/2] regmap: Allow installing custom reg_update_bits function
On Thu, 1 Oct 2015, Mark Brown wrote:
> On Thu, Oct 01, 2015 at 02:33:06AM -0400, j...@ringle.org wrote:
>
> > @@ -2509,6 +2510,10 @@ static int _regmap_update_bits(struct regmap *map,
> > unsigned int reg,
> > int ret;
> > unsigned int tmp, orig;
> >
> > + if (map->reg_update_bits)
> > + return map->reg_update_bits(map->bus_context, reg, mask, val,
> > + change, force_write);
> > +
> > ret = _regmap_read(map, reg, &orig);
> > if (ret != 0)
> > return ret;
>
> This completely bypasses and therefore breaks the cache infrastructure.
>
Hi Mark,
Right after sending the v2 patch, I realized that calling the
custom reg_update_bits would only be applicable for registers that are
marked as volatile. Would the following solution be acceptable (it would
also simplify the regmap_update_bits in the encx24j600 driver):
if (regmap_volatile(map, reg) && map->reg_update_bits) {
return map->reg_update_bits(map->bus_context, reg, mask,
val, change, force_write);
The cache state should not matter for volatile registers, right?
-Jon
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Re: [PATCH 1/2] regmap: Allow installing custom reg_update_bits function
On Thu, Oct 01, 2015 at 02:33:06AM -0400, j...@ringle.org wrote: > @@ -2509,6 +2510,10 @@ static int _regmap_update_bits(struct regmap *map, > unsigned int reg, > int ret; > unsigned int tmp, orig; > > + if (map->reg_update_bits) > + return map->reg_update_bits(map->bus_context, reg, mask, val, > + change, force_write); > + > ret = _regmap_read(map, reg, &orig); > if (ret != 0) > return ret; This completely bypasses and therefore breaks the cache infrastructure. signature.asc Description: Digital signature
