[PATCH v3 10/24] drm/i2c: tda998x: don't read write-only registers
Russell King - ARM Linux
linux at arm.linux.org.uk
Wed Jan 22 16:35:35 EST 2014
On Sun, Jan 19, 2014 at 07:58:42PM +0100, Jean-Francois Moine wrote:
> This patch takes care of the write-only registers of the tda998x.
>
> The value 'MAT_CONTRL_MAT_SC(1)' in the register MAT_CONTRL has been
> set as it is at reset time.
>
> Signed-off-by: Jean-Francois Moine <moinejf at free.fr>
> ---
> v3
> - remarks from Russell King
> - don't move the sync polarity setting after the setting of the
> register TBG_CNTRL_0 which must be the last setting of the
> init sequence
This is better, except I find that there's an additional change in this
version which wasn't in the original patch 9:
> /* must be last register set: */
> - reg_clear(priv, REG_TBG_CNTRL_0, TBG_CNTRL_0_SYNC_ONCE);
> + reg_write(priv, REG_TBG_CNTRL_0, 0);
Register changes which have a potential effect shouldn't be part of a
patch which is really only trying to avoid reading from write only
registers.
This could be a potential functional change - and it's probably one
which Rob Clark should at least be made aware of. As I commented last
time, when you're changing register values in an otherwise innocuous
patch, you should comment about them in the patch description.
--
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