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

From: Jagan Teki
Date: Mon Nov 19 2018 - 05:58:45 EST


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?

[1] https://patchwork.kernel.org/patch/10666599/