2015-04-14 13:57 GMT+02:00 Sascha Hauer <s.ha...@pengutronix.de>: > On Tue, Apr 14, 2015 at 01:01:30PM +0200, Matthias Brugger wrote: >> Hi Sascha, >> >> 2015-04-14 12:08 GMT+02:00 Sascha Hauer <s.ha...@pengutronix.de>: >> > Hi Matthias, >> > >> > On Tue, Apr 07, 2015 at 01:47:58PM +0200, Matthias Brugger wrote: >> >> Hi Sascha, >> >> >> >> >> >> 2015-03-31 20:16 GMT+02:00 Sascha Hauer <s.ha...@pengutronix.de>: >> >> > >> >> > The following changes since commit >> >> > 9eccca0843205f87c00404b663188b88eb248051: >> >> > >> >> > Linux 4.0-rc3 (2015-03-08 16:09:09 -0700) >> >> > >> >> > are available in the git repository at: >> >> > >> >> > git://git.pengutronix.de/git/imx/linux-2.6.git >> >> > tags/v4.0-clk-mediatek-v11 >> >> > >> >> > for you to fetch changes up to ae9129219143cfdefe8b3a463deb8c5cb8955525: >> >> > >> >> > dt-bindings: ARM: Mediatek: Document devicetree bindings for >> >> > clock/reset controllers (2015-03-31 20:08:46 +0200) >> >> > >> >> > ---------------------------------------------------------------- >> >> > This patchset contains the initial common clock support for Mediatek >> >> > SoCs. >> >> > Mediatek SoC's clock architecture comprises of various PLLs, dividers, >> >> > muxes >> >> > and clock gates. >> >> >> >> I tried the patch set on my mt8135 eval board. I used the dts bindings >> >> from a former version of this set [1], but it does not boot the board >> >> (based on v4.0-rc7). >> >> Do you have any hint, what is happening, or are the bindings wrong? >> > >> > I just tried on a v4.0 with >> > - this series applied >> > - the dts patch applied (which is still up-to-date) >> > - multi_v7_defconfig >> > >> > And it still works. What do you mean with "does not boot the board"? No >> > console output? Could you try with earlyprintk? >> >> The probelms I see is, that with the clock patches, I'm not able to >> boot into a initramfs [1]. >> Whereas if I just comment topckgen and preicfg in the dts, I'm able to >> get the a serial console of my initramfs [2]. >> >> I wonder if you are able to get serial console from the initramfs with >> the clock patches + dts patch? > > So you get kernel messages but no output from initramfs? In this case > the kernel disables the unused clocks in a late_initcall. The UART > driver still uses the dummy clock provided in the dtsi, so the real > UART clk gets disabled in the initcall. Try passing clk_ignore_unused to > the kernel
OK, I can boot to the initramfs with this kernel parameter, but it fails to boot, when I change the uart clock. I suppose that PERI_UART3 for debug port uart3 should be fine, but it looks like it doesn't work. I can see on the mt6589 datasheet that you have a register PERI_UART_CK_SOURCE_SEL where you can decide if you want a 26 MHz or a 52 MHz clock for the UART block. Does this register exists on mt8135? If so, why is it not implemented? -- motzblog.wordpress.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
