Hi Jacopo, On Friday 03 Mar 2017 13:37:56 jacopo mondi wrote: > On 03/03/2017 12:26, Laurent Pinchart wrote: > > On Friday 03 Mar 2017 09:09:38 Jacopo Mondi wrote: > >> On Gen3 platforms compositing planes are allocated by VSP on behalf of > >> DRM/KMS. If VSP support is not compiled in, vsp1 initialization stub > >> routine is called, leading to invalid memory accesses later on when un- > >> initialized planes are accessed. > >> > >> Fail explicitly earlier if planes are not properly created. > >> > >> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> > >> --- > >> > >> drivers/gpu/drm/rcar-du/rcar_du_kms.c | 3 +++ > >> 1 file changed, 3 insertions(+) > >> > >> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c > >> b/drivers/gpu/drm/rcar-du/rcar_du_kms.c index b5d3f16..7f56c09 100644 > >> --- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c > >> +++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c > >> @@ -616,6 +616,9 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu) > >> ret = rcar_du_vsp_init(vsp); > >> if (ret < 0) > >> return ret; > >> + > >> + if (!vsp->planes) > >> + return -EINVAL; > > > > Given that this code is only called when the DU hardware requires the VSP > > to operate, how about modifying the rcar_du_vsp_init() stub function to > > return - ENXIO instead of 0 ? That way you won't need to add an > > additional check here. > > Ok, I'll make sure it is only called there also. > > > Ideally we should require VSP through Kconfig as well. If you feel like > > submitting a patch (and testing it with various combinations of module and > > built-in) it would be appreciated. > > That would be ideal. > Am I wrong or the condition that selects DRM_RCAR_VSP is (DRM_RCAR_DU && > Gen3-platform)? Implying that on Gen2 DU can live without VSP enabled? That's correct. On Gen2 VSP isn't required to operate the display. > >> } > >> > >> } -- Regards, Laurent Pinchart
