Re: [PATCH] drm/stm: Remove usage of drm_display_mode_to_videomode()

[Philippe CORNU <philippe.cornu@xxxxxxxxxxx>]

Hi Marek,

Many thanks for your patch and sorry for the delay regarding this "last 
Christmas" patch (Dec. 24, 2020), lost in my inbox :(

Could you please resend it (as I did not succeed to apply it directly)?

patchwork reference 
https://patchwork.freedesktop.org/patch/409968/?series=85222

Many thanks,
Philippe :-)


On 5/28/21 4:01 PM, yannick Fertre wrote:
> Hi Philippe,
> I have already reviewed this patch on January 7, 2020.
> (https://lore.kernel.org/dri-devel/0ab4ee45-4437-3b02-cf63-0e3b1b53920f@xxxxxx/) 
>
> Could you please review it and merge it?
>
> Best regards
>
> Yannick
>
> On 5/28/21 10:05 AM, Yannick Fertre wrote:
> > There is not much value in the extra conversion step, the calculations
> > required for the LTDC IP are different than what is used in the
> > drm_display_mode_to_videomode(), so just do the right ones in the LTDC
> > driver right away.
> >
> > Signed-off-by: Marek Vasut <marex@xxxxxxx>
> > Signed-off-by: Yannick Fertre <yannick.fertre@xxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/stm/ltdc.c | 32 +++++++++++++++++---------------
> >   1 file changed, 17 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> > index e99771b947b6..d113b9be12c0 100644
> > --- a/drivers/gpu/drm/stm/ltdc.c
> > +++ b/drivers/gpu/drm/stm/ltdc.c
> > @@ -570,31 +570,33 @@ static void ltdc_crtc_mode_set_nofb(struct 
> > drm_crtc *crtc)
> >           }
> >       }
> > -    drm_display_mode_to_videomode(mode, &vm);
> > -
> >       DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
> > -    DRM_DEBUG_DRIVER("Video mode: %dx%d", vm.hactive, vm.vactive);
> > +    DRM_DEBUG_DRIVER("Video mode: %dx%d", mode->hdisplay, 
> > mode->vdisplay);
> >       DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
> > -             vm.hfront_porch, vm.hback_porch, vm.hsync_len,
> > -             vm.vfront_porch, vm.vback_porch, vm.vsync_len);
> > +             mode->hsync_start - mode->hdisplay,
> > +             mode->htotal - mode->hsync_end,
> > +             mode->hsync_end - mode->hsync_start,
> > +             mode->vsync_start - mode->vdisplay,
> > +             mode->vtotal - mode->vsync_end,
> > +             mode->vsync_end - mode->vsync_start);
> >       /* Convert video timings to ltdc timings */
> > -    hsync = vm.hsync_len - 1;
> > -    vsync = vm.vsync_len - 1;
> > -    accum_hbp = hsync + vm.hback_porch;
> > -    accum_vbp = vsync + vm.vback_porch;
> > -    accum_act_w = accum_hbp + vm.hactive;
> > -    accum_act_h = accum_vbp + vm.vactive;
> > -    total_width = accum_act_w + vm.hfront_porch;
> > -    total_height = accum_act_h + vm.vfront_porch;
> > +    hsync = mode->hsync_end - mode->hsync_start - 1;
> > +    vsync = mode->vsync_end - mode->vsync_start - 1;
> > +    accum_hbp = mode->htotal - mode->hsync_start - 1;
> > +    accum_vbp = mode->vtotal - mode->vsync_start - 1;
> > +    accum_act_w = accum_hbp + mode->hdisplay;
> > +    accum_act_h = accum_vbp + mode->vdisplay;
> > +    total_width = mode->htotal - 1;
> > +    total_height = mode->vtotal - 1;
> >       /* Configures the HS, VS, DE and PC polarities. Default Active 
> > Low */
> >       val = 0;
> > -    if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
> > +    if (mode->flags & DRM_MODE_FLAG_PHSYNC)
> >           val |= GCR_HSPOL;
> > -    if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
> > +    if (mode->flags & DRM_MODE_FLAG_PVSYNC)
> >           val |= GCR_VSPOL;
> >       if (bus_flags & DRM_BUS_FLAG_DE_LOW)