[PATCH 01/23] ARM: OMAP2+: clock: move clock provider infrastructure to clock driver

[Tony Lindgren]

* Tomi Valkeinen <tomi.valkeinen at ti.com> [150127 03:37]:
> On 26/01/15 17:49, Tony Lindgren wrote:
> 
> >> I'm not sure if I miss something, but regmap_write does not protect from
> >> problems if there are multiple users for the same registers. You need to
> >> use regmap_update_bits() to get a protected read/write sequence, in
> >> which you can change only the bits that you want to change.
> > 
> > To me it seems that issue can be fixed by making all the code use regmap.
> > AFAIK that should work for the legacy code too.
> 
> Even if everybody uses regmap, doing
> 
> v = regmap_read()
> modify v
> regmap_write(v)
> 
> is racy. regmap_update_bits() has to be used to protect the read/write
> sequence. Which may be somewhat challenging at times with some strange
> registers, the like Roger Q encountered recently related to CAN.

Yeah that's a good point.

Regards,

Tony