Thinkpad T410: resume broken

[John Baldwin]

On 5/16/14, 2:10 PM, Kevin Oberman wrote:
> On Fri, May 16, 2014 at 10:44 AM, Adrian Chadd <adrian at freebsd.org> wrote:
> 
>> Hi!
>>
>> I wonder what changed between 9.2-RELEASE and 10.0-RELEASE.
>>
>> Please poke me about this next week. I'm busy this week with work and
>> maker faire but I will try to help you later.
>>
>> (It's possible something like ACPI updates or a driver update has
>> broken things.)
>>
>>
>> -a
>>
> 
> Does your kernel include VESA? My T320 behaved as you describe until I
> removed VESA from my kernel. I think using vt may also fix this without the
> need to remove VESA, bug I have not gotten around to confirming this.

To be clear, vt does not fix resume.  Using i915kms is what actually
fixes resume when using Intel GPUs on the Thinkpad as i915kms is what
actually turns the LCD backlight on during resume.  You just have to use
vt to have a useable console when you use i915kms.  You can
suspend/resume fine in X with syscons + i915kms, you just can't use your
console if you do.

If you are using the Nvidia GPU, then i915kms can't help you with
turning the LCD backlight back on (and using vt shouldn't make any
difference).  VESA needs to be removed for i915kms, but I've no idea if
it needs to be removed for Nvidia.  The video reset code was reworked in
10 so that having VESA is supposed to be like using
'hw.acpi.reset_video=1' on 9, but in theory it works more often.  The
ACPI_PM setting to the kernel module along with removing VESA would seem
like your best bet, but I see in follow-ups that that wasn't completely
reliable.  However, you can try using ACPI_PM with syscons, no need to
use vt.

-- 
John Baldwin