On 19/10/17 19:42, Nicolin Chen wrote: > On Thu, Oct 19, 2017 at 11:44:22AM +0200, Thierry Reding wrote: >>>> Below is the call trace of tegra210_init_pllu() function: >>>> start_kernel() >>>> -> time_init() >>>> --> of_clk_init() >>>> ---> tegra210_clock_init() >>>> ----> tegra210_pll_init() >>>> -----> tegra210_init_pllu() > >> I'm wondering why we're not seeing a splat for this. Usually the kernel >> will warn if you sleep during atomic context. Does this mean we're just >> not hitting that case? > > Yes. > >> readx_poll_timeout() has a might_sleep_if(), and >> therefore it should always cause the splat. > > That's true as long as CONFIG_DEBUG_ATOMIC_SLEEP is enabled locally. > >> Any ideas why this has gone unnoticed for all this time? > > We can see in the tegra210_init_pllu() function that it'll not call > tegra210_enable_pllu() if pllu is already enabled (by bootloader). I was thinking that same and so I clobbered the PLLU enable bit with u-boot, however, then the kernel appears to hang on boot when enabling the PLL. So although this is probably a separate issue, I am curious if you have booted the mainline with the PLLU disabled? Cheers Jon -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
