Jani, all, On a Lenovo X1 Carbon if the display is off when suspend is entered it will be off when it is resumed. A key must be pressed to restore normal brightness. xset dpms force off sleep 1 sudo systemctl suspend (resume) (screen off, press any key) The behavior I am accustomed to is for it to resume with the screen on. All of my other machines behave this way and the X1 Carbon behaved this way in the past. I performed a bisect and found that the following commit introduced the problem. From 6dda730e55f412a6dfb181cae6784822ba463847 Mon Sep 17 00:00:00 2001 From: Jani Nikula <jani.nikula@xxxxxxxxx> Date: Tue, 24 Jun 2014 18:27:40 +0300 Subject: [PATCH] drm/i915: respect the VBT minimum backlight brightness Historically we've exposed the full backlight PWM duty cycle range to the userspace, in the name of "mechanism, not policy". However, it turns out there are both panels and board designs where there is a minimum duty cycle that is required for proper operation. The minimum duty cycle is available in the VBT. The backlight class sysfs interface does not make any promises to the userspace about the physical meaning of the range 0..max_brightness. Specifically there is no guarantee that 0 means off; indeed for acpi_backlight 0 usually is not off, but the minimum acceptable value. Respect the minimum backlight, and expose the range acceptable to the hardware as 0..max_brightness to the userspace via the backlight class device; 0 means the minimum acceptable enabled value. To switch off the backlight, the user must disable the encoder. As a side effect, make the backlight class device max brightness and physical PWM modulation frequency (i.e. max duty cycle) independent. This allows a follow-up patch to virtualize the max value exposed to the userspace. Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> Reviewed-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> [danvet: s/BUG_ON/WARN_ON/] Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> -- - Jeremiah Mahler _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
