Re: [PATCH v3 07/24] drm/i2c: tda998x: set the video mode from theadjusted value

From: Darren Etheridge
Date: Tue Jan 28 2014 - 14:20:50 EST


Jean-Francois Moine <moinejf@xxxxxxx> wrote on Tue [2014-Jan-28 18:12:18 +0100]:
> On Thu, 23 Jan 2014 17:29:07 -0600
> Darren Etheridge <detheridge@xxxxxx> wrote:
>
> > > @@ -896,9 +897,9 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder,
> > > * TDA19988 requires high-active sync at input stage,
> > > * so invert low-active sync provided by master encoder here
> > > */
> > > - if (mode->flags & DRM_MODE_FLAG_NHSYNC)
> > > + if (adj_mode->flags & DRM_MODE_FLAG_NHSYNC)
> > > reg_set(priv, REG_VIP_CNTRL_3, VIP_CNTRL_3_H_TGL);
> > > - if (mode->flags & DRM_MODE_FLAG_NVSYNC)
> > > + if (adj_mode->flags & DRM_MODE_FLAG_NVSYNC)
> > > reg_set(priv, REG_VIP_CNTRL_3, VIP_CNTRL_3_V_TGL);
> > >
> >
> > Using the adj_mode->flags breaks a workaround I had done on BeagleBone Black
> > (tilcdc + tda998x) to resolve an issue with out of spec syncs from the
> > tlcdc. I invert the HSYNC in adj_mode->flags but don't want the tda998x to
> > really know that I am doing that so I use adj_mode in the tilcdc driver, and
> > mode here in the tda998x driver. The theory being adj_mode contains whatever
> > workarounds I need to do for the driving device and mode has the pristine
> > values that I want to send to the monitor. I would need to look if there is a
> > different way to solve this as I am guessing you are actually using adj_mode in
> > the manner it was intended.
>
> No. In fact, I just wanted the function to use only one mode.
>
> Looking at the other drivers, it seems that they don't touch the
> adjusted_mode, so, for the Cubox, mode and adjusted_mode have same
> values.
>
> I will do an other patch so that you will not have to touch the tilcdc
> driver.
>
Thanks, that would certainly be the easiest path to avoid the regression given
the other drivers that use tda998x don't currently use adj_mode. However I
don't disagree with your reasoning, it would make sense to only use values
from one of the strctures and not a mix and match. Anybody looking at only
the tda998x driver would be confused :) I'll work on finding a different
solution for this.

> --
> Ken ar c'hentañ | ** Breizh ha Linux atav! **
> Jef | http://moinejf.free.fr/
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