Re: [PATCH][RESEND] Revert "PM: ACPI: reboot: Use S5 for reboot"

From: Josef Bacik
Date: Wed Mar 17 2021 - 13:26:39 EST

On 3/17/21 12:14 PM, Kai-Heng Feng wrote:
On Wed, Mar 17, 2021 at 11:19 PM Josef Bacik <josef@xxxxxxxxxxxxxx> wrote:

On 3/16/21 10:50 PM, Kai-Heng Feng wrote:

On Wed, Mar 17, 2021 at 10:17 AM Josef Bacik <josef@xxxxxxxxxxxxxx> wrote:

This reverts commit d60cd06331a3566d3305b3c7b566e79edf4e2095.

This patch causes a panic when rebooting my Dell Poweredge r440. I do
not have the full panic log as it's lost at that stage of the reboot and
I do not have a serial console. Reverting this patch makes my system
able to reboot again.

But this patch also helps many HP laptops, so maybe we should figure
out what's going on on Poweredge r440.
Does it also panic on shutdown?

Sure I'll test whatever to get it fixed, but I just wasted 3 days bisecting and
lost a weekend of performance testing on btrfs because of this regression, so
until you figure out how it broke it needs to be reverted so people don't have
to figure out why reboot suddenly isn't working.

That's unfortunate to hear. However, I've been spending tons of time
on bisecting kernels. To me it's just a normal part of kernel
development so I won't call it "wasted".

Feel free to revert the patch though.

Running "halt" has the same effect with and without your patch, it gets to
"system halted" and just sits there without powering off. Not entirely sure why
that is, but there's no panic.

What about shutdown? pm_power_off_prepare() is used by shutdown but
it's not used by halt.

"shutdown now" works fine with and without your patch. Thanks,