[Intel-gfx] [PATCH 0/6] drm/i915: Reject bogus modes with fixed mode panels

[Jani Nikula]

On Thu, 23 Sep 2021, Ville Syrjala <ville.syrjala at linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Let's start to reject user modes whose refresh rate is
> nowhere near the actual fixed mode refresh rate we're
> going to use. ATM we're just flat out lying to the user.

I eyeballed through this quickly, mostly seems reasonable, I'll try to
do detailed review later.

One question though. I think we have bug reports [1][2] about panels
that support very high refresh rates, but report a lower refresh rate
mode as the preferred mode. It's perhaps a safe default from a power
usage standpoint. Does this series make using those modes harder or
impossible?

BR,
Jani.


[1] https://gitlab.freedesktop.org/drm/intel/-/issues/2939
[2] https://gitlab.freedesktop.org/drm/intel/-/issues/3969


>
> We'll also pimp the connector's mode list validation 
> a bit.
>
> Ville Syrjälä (6):
>   drm/i915: Extract intel_panel_mode_valid()
>   drm/i915: Use intel_panel_mode_valid() for DSI/LVDS/DVO
>   drm/i915: Reject modes that don't match fixed_mode vrefresh
>   drm/i915: Introduce intel_panel_compute_config()
>   drm/i915: Reject user modes that don't match fixed mode's refresh rate
>   drm/i915: Drop pointless fixed_mode checks from dsi code
>
>  drivers/gpu/drm/i915/display/icl_dsi.c     |  7 ++--
>  drivers/gpu/drm/i915/display/intel_dp.c    | 13 ++++---
>  drivers/gpu/drm/i915/display/intel_dsi.c   | 16 ++++-----
>  drivers/gpu/drm/i915/display/intel_dvo.c   | 24 ++++++++-----
>  drivers/gpu/drm/i915/display/intel_lvds.c  | 15 ++++----
>  drivers/gpu/drm/i915/display/intel_panel.c | 41 ++++++++++++++++++++--
>  drivers/gpu/drm/i915/display/intel_panel.h |  5 +++
>  drivers/gpu/drm/i915/display/intel_sdvo.c  | 21 ++++++-----
>  drivers/gpu/drm/i915/display/vlv_dsi.c     | 39 +++++++++-----------
>  9 files changed, 116 insertions(+), 65 deletions(-)

-- 
Jani Nikula, Intel Open Source Graphics Center