Re: Reboot regression on Lager

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Wolfram,

On Wed, Dec 23, 2020 at 7:55 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> I just discovered that my Lager can't reboot anymore. 5.10 is good,
> current Linus' tree [1] is bad. I don't have time to debug this on my
> own right now, so this is a reminder and notification for now.
>
> [1] (614cb5894306 ("Merge tag 'acpi-5.11-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm")
>
> Happy hacking,
>
>    Wolfram
>
> ===
>
> [    8.280735] Unhandled fault: imprecise external abort (0x1406) at 0x00000000

That usually indicates that a module's registers are accessed,
while the module clock is disabled.

> [    8.287793] pgd = (ptrval)
> [    8.290504] [00000000] *pgd=41d85835, *pte=00000000, *ppte=00000000
> [    8.296794] Internal error: : 1406 [#1] ARM
> [    8.300983] Modules linked in:
> [    8.304044] CPU: 0 PID: 1173 Comm: init Tainted: G        W         5.10.0-12913-g614cb5894306 #1092
> [    8.313187] Hardware name: Generic R-Car Gen2 (Flattened Device Tree)
> [    8.319632] PC is at sh_mdio_ctrl+0x44/0x60
> [    8.323831] LR is at sh_mmd_ctrl+0x20/0x24

So sh_eth is already suspended at this point.

Can you reproduce it at will? Koelsch is still rebooting fine.
But I caught the following during s2ram once, which might be related:

 Disabling non-boot CPUs ...
 Enabling non-boot CPUs ...
+------------[ cut here ]------------
+WARNING: CPU: 0 PID: 21 at drivers/i2c/i2c-core.h:54 __i2c_transfer+0x464/0x4a0
+i2c i2c-6: Transfer while suspended
+CPU: 0 PID: 21 Comm: kworker/0:1 Not tainted
5.11.0-rc1-shmobile-00107-gcf9760aa181f #829
+Hardware name: Generic R-Car Gen2 (Flattened Device Tree)
+Workqueue: events_power_efficient sync_hw_clock
+[<c010dba4>] (unwind_backtrace) from [<c0109b28>] (show_stack+0x10/0x14)
+[<c0109b28>] (show_stack) from [<c07a120c>] (dump_stack+0x8c/0xa8)
+[<c07a120c>] (dump_stack) from [<c011c538>] (__warn+0xc0/0xec)
+[<c011c538>] (__warn) from [<c079a7bc>] (warn_slowpath_fmt+0x78/0xb0)
+[<c079a7bc>] (warn_slowpath_fmt) from [<c0566574>] (__i2c_transfer+0x464/0x4a0)
+[<c0566574>] (__i2c_transfer) from [<c0566608>] (i2c_transfer+0x58/0xf8)
+[<c0566608>] (i2c_transfer) from [<c0489f80>] (regmap_i2c_read+0x58/0x94)
+[<c0489f80>] (regmap_i2c_read) from [<c0485e00>] (_regmap_raw_read+0x108/0x1bc)
+[<c0485e00>] (_regmap_raw_read) from [<c0485ef8>] (_regmap_bus_read+0x44/0x68)
+[<c0485ef8>] (_regmap_bus_read) from [<c0484018>] (_regmap_read+0x84/0x100)
+[<c0484018>] (_regmap_read) from [<c0485444>] (_regmap_update_bits+0xa8/0xf4)
+[<c0485444>] (_regmap_update_bits) from [<c0485574>]
(_regmap_select_page+0xe4/0x100)
+[<c0485574>] (_regmap_select_page) from [<c0485664>]
(_regmap_raw_write_impl+0xd4/0x608)
+[<c0485664>] (_regmap_raw_write_impl) from [<c04863f4>]
(_regmap_raw_write+0xd8/0x114)
+[<c04863f4>] (_regmap_raw_write) from [<c0486488>] (regmap_raw_write+0x58/0x7c)
+[<c0486488>] (regmap_raw_write) from [<c04866cc>]
(regmap_bulk_write+0x118/0x13c)
+[<c04866cc>] (regmap_bulk_write) from [<c05605b4>]
(da9063_rtc_set_time+0x44/0x8c)
+[<c05605b4>] (da9063_rtc_set_time) from [<c055e428>] (rtc_set_time+0x8c/0x15c)
+[<c055e428>] (rtc_set_time) from [<c01872cc>] (sync_hw_clock+0x12c/0x210)
+[<c01872cc>] (sync_hw_clock) from [<c01337d0>] (process_one_work+0x1bc/0x2ac)
+[<c01337d0>] (process_one_work) from [<c0133b18>] (worker_thread+0x22c/0x2d0)
+[<c0133b18>] (worker_thread) from [<c01388a8>] (kthread+0x100/0x10c)
+[<c01388a8>] (kthread) from [<c0100150>] (ret_from_fork+0x14/0x24)
+Exception stack(0xc1195fb0 to 0xc1195ff8)
+5fa0:                                     00000000 00000000 00000000 00000000
+5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
+5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
+---[ end trace 5d3a7a10ee0cec3d ]---
+da9063-rtc da9063-rtc: Failed to set RTC time data: -108
+da9063-rtc da9063-rtc: Failed to read RTC time data: -108
 CPU1 is up

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds