Messages in this thread | | | Date | Thu, 19 Oct 2017 11:42:24 -0700 | From | Nicolin Chen <> | Subject | Re: [PATCH v2] clk: tegra: Use readl_relaxed_poll_timeout_atomic in tegra210_clock_init |
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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).
You can verify it by adding an irqs_disabled() in this routine. The function is called during system-boot and suspend-n-resume. And both cases should be irqs_disabled().
Thanks Nicolin
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