Re: [PATCH v2 01/12] drm/sun4i: sun6i_mipi_dsi: Compute burst mode loop N1 instruction delay

[Maxime Ripard]

On Mon, Nov 19, 2018 at 04:28:29PM +0530, Jagan Teki wrote:
> On Mon, Nov 19, 2018 at 1:57 PM Maxime Ripard <maxime.ripard@xxxxxxxxxxx> wrote:
> >
> > On Fri, Nov 16, 2018 at 10:09:05PM +0530, Jagan Teki wrote:
> > > Loop N1 instruction delay for burst mode lcd panel are
> > > computed as per BSP code.
> > >
> > > Reference code is available in BSP (from linux-sunxi
> > > drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c)
> > >
> > > dsi_dev[sel]->dsi_inst_loop_num.bits.loop_n1=
> > > (panel->lcd_ht-panel->lcd_x)*(150)/(panel->lcd_dclk_freq*8) - 50;
> > > => (((mode->htotal - mode->hdisplay) * 150) /
> > >      ((mode->clock / 1000) * 8)) - 50;
> > >
> > > So use the similar computation for loop N1 delay.
> > >
> > > Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
> >
> > *why* are you doing this? What is it fixing? on which devices?
> 
> You mentioned the separate function to compute the delay for all modes
> [1], ie what I did. did I missing anything?

You're missing that you are never explaining why that patch is needed
in the first place. Or answering the question I asked a couple of
lines above.

Maxime

-- 
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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