Re: [Intel-gfx] Enabling i915 Panel Self Refresh by default on some devices ?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On Thu, 2018-02-01 at 13:31 +0100, Hans de Goede wrote:
> Hi All,
> 
> As you may have heard I've recently been working on improving
> Linux laptop battery life, specifically the OOTB experience
> without tweaking any options such as e.g. powertop --auto-tune
> would do, see:
> 
> https://fedoraproject.org/wiki/Changes/ImprovedLaptopBatteryLife
> 
> So far this is going quite nicely, it looks like Fedora 28
> will have SATA ALPM (big win), autosuspend of USB Bluetooth HCIs
> and snd_intel_hda powersaving all enabled OOTB.
> 
> Looking for more savings I've run some quick tests with
> i915.enable_psr=1, this seems to be another nice win (for an idle
> system) of aprox. 0.5W.
> 
> So as with the other 3 items I just mentioned I'm now looking into
> somehow enabling this be default, at least one some models.
> 
> Currently I'm thinking doing a whitelist or blacklist (*) for this,
> but first I think we need some more data about on how much models
> this just works and where it is causing issues, as such I've done
> a blog post to gather this data:
> 
> https://hansdegoede.livejournal.com/18653.html
> 
> So I will revisit this eventually, once people have had some time
> to respond to this blog-post.
> 
> In the mean time I wonder if anyone can explain why this options
> is currently disabled by default. E.g. are there any known specific
> models laptops / panels which are causing issues, are the bugzillas
> for this? Etc. ?
> 

I somehow missed reading your post.

There are few issues I know of:
1) frame counter reset that causes long vblank waits
2) fbcon screen freeze 
3) driver v/s HW aux channel usage needs to be serialized
4) occasional cursor lag
5) lack of IGT's to verify correctness

The first two have patches on the list, the third is being worked on.
The fourth needs investigation.


> Also does anyone know if any problems are mainly panel or laptop
> model specific ? I would expect this to mostly be panel specific
> and not depend on the model laptop (given then certain models
> ship with different panels over their production lifetime).

I am sure there are panel issues, but I haven't looked into them yet.
Like Rodrigo suggested, we probably have to rely on VBT for this and
enable PSR by default on only those panels.


> 
> Regards,
> 
> Hans
> 
> p.s.
> 
> If anyone on this list can make 10 minutes to run the tests
> described in my blogpost and gather the data mentioned there, then
> that would be great.
> 
> 
> *) I know that maintaining such a white/blacklist in the kernel
> is going to be a pain, so my current thinking on this is to make
> this runtime configurable through a sysfs attribute and then
> use a udev rule + udev hwdb entries for this.
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel




[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux