On 25/11/15 15:52, Tyler Baker wrote: > On 25 November 2015 at 07:11, Thierry Reding <thierry.red...@gmail.com> wrote: >> On Mon, Nov 23, 2015 at 03:18:59PM -0800, Tyler Baker wrote: >>> Hi Jon, >>> >>> On 20 November 2015 at 07:11, Jon Hunter <jonath...@nvidia.com> wrote: >>>> The _clk_disable_pll() function will attempt to place a PLL into bypass >>>> if the TEGRA_PLL_BYPASS is specified for the PLL and then disable the PLL >>>> by clearing the enable bit. To place the PLL into bypass, the bypass bit >>>> needs to be set and not cleared. Fix this by setting the bypass bit and >>>> not clearing it. >>>> >>>> Signed-off-by: Jon Hunter <jonath...@nvidia.com> >>> >>> The kernelci.org bot recently detected a jetson-tk1 boot failure[1][2] >>> in the tegra tree. This boot failure has only been observed when >>> booting with a multi_v7_defconfig kernel variant. The bot bisected[3] >>> this boot failure to this commit, and I confirmed reverting it on top >>> of the tegra for-next branch resolves the issue. The ramdisk[4] used >>> for booting is loaded with the modules from the build. It appears to >>> me that as the modules are being loaded in userspace by eudev the >>> jetson-tk1 locks up. I've sifted through the console logs a bit, and >>> found this splat to be most interesting[5]. Can you confirm this >>> issue on your end? >> >> Just to close the loop on this: we've discussed this on IRC and came to >> the conclusion that not using the bypass mode is safer (switching into >> and out of bypass can glitch). I've dropped this patch for now and Jon >> will be looking into a second revision of the patch which, in addition >> to fixing bypass (the fix is legit, it just happens to break because of >> the glitch, most likely), will also remove the BYPASS flag setting so >> that bypass will not be used. > > Thanks for the update, I appreciate you guys looking into this issue. > Please CC me on any fixes, I can re-test and give my tested-by.
No problem. On 2nd thoughts I am wondering if there is any value in bypassing the PLL when disabling it. I will look into this and see what I find out. Cheers Jon -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
