Hi Kieran, On Tue, Jul 9, 2019 at 12:07 PM Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx> wrote: > On 09/07/2019 10:59, Geert Uytterhoeven wrote: > > When support for the IPMMU is not enabled, the FDP driver may be > > probe-deferred multiple times, causing several messages to be printed > > like: > > > > rcar_fdp1 fe940000.fdp1: FCP not found (-517) > > rcar_fdp1 fe944000.fdp1: FCP not found (-517) > > > > Fix this by reducing the message level to debug level, as is done in the > > VSP1 driver. > > Does the lack of IPMMU prevent the FDP1 being loaded entirely? No it doesn't. If CONFIG_IPMMU_VMSA=n, rcar_fdp1 fe940000.fdp1: FCP not found (-517) rcar_fdp1 fe944000.fdp1: FCP not found (-517) rcar_fdp1 fe940000.fdp1: FCP not found (-517) rcar_fdp1 fe944000.fdp1: FCP not found (-517) rcar_fdp1 fe940000.fdp1: FCP not found (-517) rcar_fdp1 fe944000.fdp1: FCP not found (-517) rcar_fdp1 fe940000.fdp1: Device registered as /dev/video8 rcar_fdp1 fe944000.fdp1: Device registered as /dev/video9 So the driver succeeds, eventually. If CONFIG_IPMMU_VMSA=y, it succeeds sooner: rcar_fdp1 fe940000.fdp1: Device registered as /dev/video0 rcar_fdp1 fe944000.fdp1: Device registered as /dev/video1 Always be prepared to handle -EPROBE_DEFER. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds