On Fri, Dec 13, 2019 at 03:34:48PM +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
>
> icl and tgl are still affected by the modulo 4 PLANE_OFFSET.y
> underrun issue. Reject such configurations on all gen9+ platforms.
>
> Can be reproduced easily with the following sequence of
> hardware poking:
> while {
> write FBC_CTL.enable=1
> wait for vblank
>
> write PLANE_OFFSET .x=0 .y=32
> write PLANE_SURF
> wait for vblank
>
> # if PLANE_OFFSET.y is multiple of 4 the underrun won't happen
> write PLANE_OFFSET .x=0 .y=31
> write PLANE_SURF
> wait for vblank
>
> # extra vblank wait is required here presumably
> # to get FBC into the proper state
> wait for vblank
>
> write FBC_CTL.enable=0
> # underrun happens some time after FBC disable
> wait for vblank
> }
>
> Both 8888 and 565 pixel formats and all tilinga formats
> seem affected. Reproduced on KBL/GLK/ICL/TGL. BDW confirmed
> not affected.
>
> Closes: https://gitlab.freedesktop.org/drm/intel/issues/792
> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Reviewed-by: Imre Deak <imre.deak@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_fbc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
> index 6f1d5c032681..a1048ece541e 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbc.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
> @@ -776,7 +776,7 @@ static bool intel_fbc_can_activate(struct intel_crtc *crtc)
> * having a Y offset that isn't divisible by 4 causes FIFO underrun
> * and screen flicker.
> */
> - if (IS_GEN_RANGE(dev_priv, 9, 10) &&
> + if (INTEL_GEN(dev_priv) >= 9 &&
> (fbc->state_cache.plane.adjusted_y & 3)) {
> fbc->no_fbc_reason = "plane Y offset is misaligned";
> return false;
> --
> 2.23.0
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
