Suspend, resume, UEFI, CSM, drm-stable-kmod and drm-next-kmod with Radeon HD 7570M

[Pete Wright]

On 8/22/18 2:11 AM, Graham Perrin wrote:
> HP EliteBook 8570p with AMD 'Thames' Radeon HD 7570M.
>
> If neither drm-stable-kmod nor drm-next-kmod is used – commenting out
> # kld_list="/boot/modules/radeonkms.ko"
> in /etc/rc.conf
> and if boot is pure UEFI, without CSM,
> then the notebook can reliably resume from suspend. There's a
> distinctive single amber pulse of the (normally blue) radio button
> before suspend occurs. However:
>
> - without CSM, most of the startup routine is illegible, 'torn'
>
> – for example, I can't see what's typed when I boot to single user mode.
>
> ----
>
> If either drm-stable-kmod or drm-next-kmod is used
> and if boot is pure UEFI,
> then the notebook can not suspend. No amber pulse of the radio button.
>
> With and without drm-next-kmod:
> if boot is hybrid UEFI with CSM,
> then suspend occurs, but resume fails. No beep, the computer restarts.
>
> debug.acpi.resume_beep=1
> in /boot/loader.conf for an audible beep.
>
> ----
>
> Please: might graphics/drm-devel-kmod be better for either the tearing (without CSM) or for suspend?

not sure this will address this specific issue - but have you tested 
setting this sysctl knob and seeing if that fixes your resume issues:
hw.acpi.reset_video=1

-pete

-- 

Pete Wright
pete at nomadlogic.org
@nomadlogicLA