[PATCH 3/3] drm: add LG eDP panel to quirk database

[Dhinakaran Pandiyan]

On Mon, 2018-09-10 at 14:43 +0300, Jani Nikula wrote:
> On Mon, 10 Sep 2018, "Lee, Shawn C" <shawn.c.lee at intel.com> wrote:
> > The N value was computed by kernel driver that based on synchronous
> > clock
> > mode. But only specific N value (0x8000) would be acceptable for
> > LG LP140WF6-SPM1 eDP panel which is running at asynchronous clock
> > mode.
> > With the other N value, Tcon will enter BITS mode and display black
> > screen.
> > Add this panel into quirk database and give particular N value when
> > calculate M/N divider.
> > 
> > Cc: Jani Nikula <jani.nikula at intel.com>
> > Cc: Cooper Chiou <cooper.chiou at intel.com>
> > Cc: Matt Atwood <matthew.s.atwood at intel.com>
> > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > Cc: Clint Taylor <clinton.a.taylor at intel.com>
> > Signed-off-by: Lee, Shawn C <shawn.c.lee at intel.com>
> 
> No access to the panel or its details, so instead of review,
> 
> Acked-by: Jani Nikula <jani.nikula at intel.com>
> 
> > ---
> >  drivers/gpu/drm/drm_dp_helper.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/drm_dp_helper.c
> > b/drivers/gpu/drm/drm_dp_helper.c
> > index d0c1250975ab..0ef7c43a9025 100644
> > --- a/drivers/gpu/drm/drm_dp_helper.c
> > +++ b/drivers/gpu/drm/drm_dp_helper.c
> > @@ -1270,6 +1270,8 @@ struct dpcd_quirk {
> >  static const struct dpcd_quirk dpcd_quirk_list[] = {
> >  	/* Analogix 7737 needs reduced M and N at HBR2 link rates
> > */
> >  	{ OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, 

Wonder if DEVICE_ID_ANY still the accurate criteria for these dongles
now that we can check against device IDs. I guess, since the quirk
fixes multiple dongles we probably can't check against a single device
ID.


> > BIT(DP_DPCD_QUIRK_CONSTANT_N) },
> > +	/* LG LP140WF6-SPM1 eDP panel */

If you are resending the patches, it might be worth updating the
comment to
/* LG LP140WF6-SPM1 eDP panel needs N value of 0x8000 */

> > +	{ OUI(0x00, 0x22, 0xb9), DEVICE_ID('s', 'i', 'v', 'a',
> > 'r', 'T'), false, BIT(DP_DPCD_QUIRK_CONSTANT_N) },
> >  };
> >  
> >  #undef OUI
> 
>