Re: [PATCH v2] drm/msm/dsi: use RMW cycles in dsi_update_dsc_timing

[Vinod Koul <vkoul@kernel.org>]

On 30-04-22, 22:28, Dmitry Baryshkov wrote:
> On 30/04/2022 21:58, Marijn Suijten wrote:
> > On 2022-04-30 20:55:33, Dmitry Baryshkov wrote:
> > > The downstream uses read-modify-write for updating command mode
> > > compression registers. Let's follow this approach. This also fixes the
> > > following warning:
> > > 
> > > drivers/gpu/drm/msm/dsi/dsi_host.c:918:23: warning: variable 'reg_ctrl' set but not used [-Wunused-but-set-variable]
> > > 
> > > Reported-by: kernel test robot <lkp@intel.com>
> > > Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration")
> > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> > 
> > I pointed this out in review multiple times, so you'll obviously get my:
> 
> I think I might have also pointed this out once (and then forgot to check
> that the issue was fixed by Vinod).

I think i have tried to reply to all comments, if anything was missed
that would be my mistake..

> > Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
> > 
> > (But are you sure there's nothing else to clear in the 1st CTRL
> > register, only the lowest 16 bits?  That should mean `reg` never
> > contains anything in 0xffff0000)
> 
> Judging from the downstream the upper half conains the same fields, but used
> for other virtual channel. I didn't research what's the difference yet. All
> the dtsi files that I have here at hand use
> 'qcom,mdss-dsi-virtual-channel-id = <0>;'

Yes the register description is for STREAM1 in documentation, it is
unclear to me when that can be used

-- 
~Vinod