Thanks Thomas, I'll pick up the fix when you post v2. It will be a week before it hits Linus' tree given that he is currently underwater. g. On Tue, May 13, 2014 at 3:30 PM, Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> wrote: > Dear Rob Herring, > > On Tue, 13 May 2014 09:00:02 -0500, Rob Herring wrote: > >> > However, it forgot to do the same for of_update_property(), which if >> > used early in the boot process (before core_initcalls have been >> > called), tries to call sysfs_remove_bin_file(), and crashes: >> >> It actually crashes or just the warning? It would be good to give the >> crash backtrace. > > It crashes after the warning. The crash trace is: > > Unable to handle kernel NULL pointer dereference at virtual address 0000003c > pgd = c0004000 > [0000003c] *pgd=00000000 > Internal error: Oops: 5 [#1] SMP ARM > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.15.0-rc1-00127-g1d7e7b2-dirty #423 > task: c10ad4d8 ti: c10a2000 task.ti: c10a2000 > PC is at kernfs_find_ns+0x8/0xf0 > LR is at kernfs_find_and_get_ns+0x30/0x48 > pc : [<c0103834>] lr : [<c010394c>] psr: 600001d3 > sp : c10a3f34 ip : 00000073 fp : 00000000 > r10: 00000000 r9 : cfffc240 r8 : cfdf2980 > r7 : cf812c00 r6 : 00000000 r5 : 00000000 r4 : c10b45e0 > r3 : c10ad4d8 r2 : 00000000 r1 : cf812c00 r0 : 00000000 > Flags: nZCv IRQs off FIQs off Mode SVC_32 ISA ARM Segment kernel > Control: 10c53c7d Table: 0000404a DAC: 00000015 > Process swapper/0 (pid: 0, stack limit = 0xc10a2240) > Stack: (0xc10a3f34 to 0xc10a4000) > 3f20: c10b45e0 00000000 00000000 > 3f40: cf812c00 c010394c 00000063 cf812c00 00000001 cf812c00 cfdf29ac c03932cc > 3f60: 00000063 cf812bc0 cfdf29ac cf812c00 ffffffff c03943f8 cfdf2980 c0104468 > 3f80: cfdf2a04 cfdf2980 cf812bc0 c06634b0 c10aa3c0 c0394da4 c10f74dc cfdf2980 > 3fa0: cf812bc0 c0647248 c10aa3c0 ffffffff c10de940 c10aa3c0 ffffffff c0640934 > 3fc0: ffffffff ffffffff c06404ec 00000000 00000000 c06634b0 00000000 10c53c7d > 3fe0: c10aa434 c06634ac c10ae4c8 0000406a 414fc091 00008070 00000000 00000000 > [<c0103834>] (kernfs_find_ns) from [<00000001>] (0x1) > Code: e5c89001 eaffffcf e92d40f0 e1a06002 (e1d023bc) > ---[ end trace 3406ff24bd97382f ]--- > Kernel panic - not syncing: Attempted to kill the idle task! > ---[ end Kernel panic - not syncing: Attempted to kill the idle task! > >> > To fix this problem, we simply skip the sysfs related calls in >> > of_update_property(), and rely on of_init() to fix up things when it >> > will be called, exactly as is done in of_add_property() and >> > of_remove_property(). >> > >> > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> >> > Fixes: 75b57ecf9d1d1e17d099ab13b8f48e6e038676be ('of: Make device nodes kobjects so they show up in sysfs') >> >> Humm, I didn't know about this new tag. This doesn't quite match what >> SubmittingPatches says. It should be 12 digits of commit hash and >> double quotes around the summary. > > Well, I guess it's a per-maintainer choice: > > git log | grep "^Fixes:" > > Fixes: 54fe26a900bc528f3df1e4235cb6b9ca5c6d4dc2 ('ARM: mvebu: Add thermal quirk for the Armada 375 DB board') > Fixes: 54397d85349f ("ARM: kirkwood: Relocate PCIe device tree nodes") > Fixes: a7d4f81821f7 ('ARM: mvebu: Add support for NOR flash device on Openblocks AX3 board') > Fixes: b484ff42df47 ('ARM: mvebu: Add support for NOR flash device on Armada XP-DB board') > Fixes: c971ff185f64 ("leds: leds-pwm: Defer led_pwm_set() if PWM can sleep") > Fixes: abccd00f8af2 ('btrfs: Fix 32/64-bit problem with BTRFS_SET_RECEIVED_SUBVOL ioctl') > Fixes: ee1e0994ab1bd (regulator: s5m8767: Use GPIO for controlling Buck9/eMMC) > Fixes: 652ed95d5fa6 (cpufreq: introduce cpufreq_generic_get() routine) > > Somewhat inconsistent :-) > > But ok, 12 digits for the commit hash, and double quotes. > >> > drivers/of/base.c | 5 +++++ >> > 1 file changed, 5 insertions(+) >> > >> > diff --git a/drivers/of/base.c b/drivers/of/base.c >> > index f72d19b..e981f09 100644 >> > --- a/drivers/of/base.c >> > +++ b/drivers/of/base.c >> > @@ -1831,11 +1831,16 @@ int of_update_property(struct device_node *np, struct property *newprop) >> > if (rc) >> > return rc; >> > >> > + /* At early boot, bail out and defer setup to of_init() */ >> > + if (!of_kset) >> > + goto skip_sysfs; >> >> I prefer to avoid the goto and do: return found ? 0 : -ENODEV; > > Ok. > >> Also, this code has changed some in 3.15 rc's, you need to rebase. >> This change needs to go into 3.15. Other platforms could be broken. > > Ok, will submit a v2 separately. > > Thanks, > > Thomas > -- > Thomas Petazzoni, CTO, Free Electrons > Embedded Linux, Kernel and Android engineering > http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html