[Intel-gfx] [PATCH 04/14] drm/i915/tgl: Fix driver crash when update_active_dpll is called

[Lucas De Marchi]

On Fri, Sep 13, 2019 at 3:33 PM José Roberto de Souza
<jose.souza at intel.com> wrote:
>
> From: "Taylor, Clinton A" <clinton.a.taylor at intel.com>
>
> TGL PLL function table doesn't include and update_active_pll function.
> The driver attempts to make a call to this function and crashes during
> PLL changes.

the crash would only occur if the port was initialized. The ordering
in this series means this is
not a "fix" but rather finishing the implementation for TC ports
before initializing them. So we may
want to adjust the commit message accordingly. The reason we missed
that for TGL is that its need came
in parallel to the TGL support hitting upstream.

My nit with this hook is that `update_active_dpll` is exclusively used
by *TC* ports on gen 11+ and
a) it's  not clear about that from the name and/or b) if it's generic
it should not crash when it's missing.

I think Imre had a patch to address it, at least renaming the hook, I
don't remember. +Imre.

Lucas De Marchi

>
> Signed-off-by: Taylor, Clinton A <clinton.a.taylor at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dpll_mgr.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> index 98288edf88f0..84e734d44828 100644
> --- a/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> +++ b/drivers/gpu/drm/i915/display/intel_dpll_mgr.c
> @@ -3479,6 +3479,7 @@ static const struct intel_dpll_mgr tgl_pll_mgr = {
>         .dpll_info = tgl_plls,
>         .get_dplls = icl_get_dplls,
>         .put_dplls = icl_put_dplls,
> +       .update_active_dpll = icl_update_active_dpll,
>         .dump_hw_state = icl_dump_hw_state,
>  };
>
> --
> 2.23.0
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx



-- 
Lucas De Marchi