Hey Geert, Thanks for you feedback, it put me on the right track. On Wed, 2016-04-06 at 12:51 +0200, Geert Uytterhoeven wrote: > Hi Sjoerd, > > On Wed, Apr 6, 2016 at 12:16 PM, Sjoerd Simons > <sjoerd.simons@xxxxxxxxxxxxxxx> wrote: > > > > I've got a Porter board (Revision B) which stopped showing serial > > output since the patch mentioned in the subject. The terrible > > clearly > > wrong hack below gets serial back (reverting to just the fck clock > > for > > scif0) on both linux-next and linux master. > Thanks for your report! > > I assume something is wrong with the SCIF_CLK input. > Hence I guess the issue is also fixed by removing the "&scif_clk" > block in > arch/arm/boot/dts/r8a7791-porter.dts? Confusingly it didn't, see the patch i just sent out: ARM: dts: r8a7791: Don't disable referenced optional clocks > > > Unfortunately I don't have enough documentation on the > > board/hardware > > to diagnose this further, but hopefully someone else does ;) > I don't have a Porter, so I based my patch on the documentation, > which states: > > The SCIF_CLK pin of the R-CarM2 is connected to the crystal > oscillator > (X4) on the R-Car M2 Application Development Board, which > supplies a clock frequency of 14.7456 MHz. > > which matches r8a7791-porter.dts, if I'm not mistaken. > > Perhaps the documentation applies to another version of the board > than > Revision B? Judging from: http://elinux.org/File:R-CarM2-KOELSCH_PORTER-B_PORTER_C_Comparison.pdf that oscillator is not mounted on porter B & C. Just sent out a revert for your patch that add this. The combination of both patches got me my serial back without weird hacks \o/ -- Sjoerd Simons Collabora Ltd.
