Messages in this thread | | | From | Enric Balletbo Serra <> | Date | Wed, 26 Feb 2020 18:15:38 +0100 | Subject | Re: next/master bisection: baseline.login on sun8i-h2-plus-orangepi-zero |
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Hi all,
Missatge de Maxime Ripard <maxime@cerno.tech> del dia dt., 25 de febr. 2020 a les 15:34: > > On Wed, Feb 19, 2020 at 03:49:47PM -0800, Stephen Boyd wrote: > > Adding some Allwinner folks. Presumably there is some sort of clk that > > is failing to calculate a phase when it gets registered. Maybe that's > > because the parent isn't registered yet? > > It's simpler than that :) > > > Quoting Guillaume Tucker (2020-02-17 23:45:41) > > > Hi Stephen, > > > > > > Please see the bisection report below about a boot failure. > > > > > > Reports aren't automatically sent to the public while we're > > > trialing new bisection features on kernelci.org but this one > > > looks valid. > > > > > > There's nothing in the serial console log, probably because it's > > > crashing too early during boot. I'm not sure if other platforms > > > on kernelci.org were hit by this in the same way, it's tricky to > > > tell partly because there is no output. It should possible to > > > run it again with earlyprintk enabled in BayLibre's test lab > > > though. > > > > > > Thanks, > > > Guillaume > > > > > > > > > On 18/02/2020 02:14, kernelci.org bot wrote: > > > > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > > > > * This automated bisection report was sent to you on the basis * > > > > * that you may be involved with the breaking commit it has * > > > > * found. No manual investigation has been done to verify it, * > > > > * and the root cause of the problem may be somewhere else. * > > > > * * > > > > * If you do send a fix, please include this trailer: * > > > > * Reported-by: "kernelci.org bot" <bot@kernelci.org> * > > > > * * > > > > * Hope this helps! * > > > > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > > > > > > > > next/master bisection: baseline.login on sun8i-h2-plus-orangepi-zero > > > > > > > > Summary: > > > > Start: c25a951c50dc Add linux-next specific files for 20200217 > > > > Plain log: https://storage.kernelci.org//next/master/next-20200217/arm/multi_v7_defconfig/gcc-8/lab-baylibre/baseline-sun8i-h2-plus-orangepi-zero.txt > > > > HTML log: https://storage.kernelci.org//next/master/next-20200217/arm/multi_v7_defconfig/gcc-8/lab-baylibre/baseline-sun8i-h2-plus-orangepi-zero.html > > > > Result: 2760878662a2 clk: Bail out when calculating phase fails during clk registration > > > > > > > > Checks: > > > > revert: PASS > > > > verify: PASS > > > > > > > > Parameters: > > > > Tree: next > > > > URL: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git > > > > Branch: master > > > > Target: sun8i-h2-plus-orangepi-zero > > > > CPU arch: arm > > > > Lab: lab-baylibre > > > > Compiler: gcc-8 > > > > Config: multi_v7_defconfig > > > > Test case: baseline.login > > > > > > > > Breaking commit found: > > > > > > > > ------------------------------------------------------------------------------- > > > > commit 2760878662a290ac57cff8a5a8d8bda8f4dddc37 > > > > Author: Stephen Boyd <sboyd@kernel.org> > > > > Date: Wed Feb 5 15:28:02 2020 -0800 > > > > > > > > clk: Bail out when calculating phase fails during clk registration > > > > > > > > Bail out of clk registration if we fail to get the phase for a clk that > > > > has a clk_ops::get_phase() callback. Print a warning too so that driver > > > > authors can easily figure out that some clk is unable to read back phase > > > > information at boot. > > > > > > > > Cc: Douglas Anderson <dianders@chromium.org> > > > > Cc: Heiko Stuebner <heiko@sntech.de> > > > > Suggested-by: Jerome Brunet <jbrunet@baylibre.com> > > > > Signed-off-by: Stephen Boyd <sboyd@kernel.org> > > > > Link: https://lkml.kernel.org/r/20200205232802.29184-5-sboyd@kernel.org > > > > Acked-by: Jerome Brunet <jbrunet@baylibre.com> > > > > > > > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > > > > index dc8bdfbd6a0c..ed1797857bae 100644 > > > > --- a/drivers/clk/clk.c > > > > +++ b/drivers/clk/clk.c > > > > @@ -3457,7 +3457,12 @@ static int __clk_core_init(struct clk_core *core) > > > > * Since a phase is by definition relative to its parent, just > > > > * query the current clock phase, or just assume it's in phase. > > > > */ > > > > - clk_core_get_phase(core); > > > > + ret = clk_core_get_phase(core); > > > > + if (ret < 0) { > > > > + pr_warn("%s: Failed to get phase for clk '%s'\n", __func__, > > > > + core->name); > > > > + goto out; > > > > + } > > The thing is, clk_core_get_phase actually returns the phase on success :) > > So, when you actually have a phase returned, and not an error, you end > up with a positive, non-zero, value for ret. > > And since it's the latest assignment of that value, and that we return > ret all the time, even on success, we end up returning that positive, > non-zero value to __clk_register, which in turn tests whether it's > non-zero for success (it's not), and then proceeds to garbage collect > everything. > > I guess we're just the odd ones actually returning non-zero phases at > init time and in kernelci. >
Just to note that not only Allwiner is affected, Rockchip is also affected by this issue. Reverting the patch fixes the issue for me, but the patch proposed by Maxime [1] does _NOT_ fixes the issue for Rockchip, there is something else, I'll take a look. I can't answer that patch because didn't reach my inbox.
Regards, Enric
[1] https://patchwork.kernel.org/patch/11403837/
> I'll send a patch > > Maxime
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