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Features Expected For Linux 5.13 From Apple M1 To FreeSync HDMI To AMD Aldebaran

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  • #11
    Originally posted by Zan Lynx View Post

    That's weird. I've been using laptops with Intel for a while and s2idle is great with them. I wonder why the AMD GPU keeps running? And I wonder if it has anything to do with PCIe power control. For s2idle to work properly it is absolutely essential that the PCIe ASPM is enabled and set to powersave.
    ASPM only matters while the device is in D0. During s2idle it should be in D3 and ASPM is not relevant.

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    • #12
      Originally posted by syrjala View Post
      ASPM only matters while the device is in D0. During s2idle it should be in D3 and ASPM is not relevant.
      This has a miss understanding of ASPM. ASPM effects your PCEe switches how they behave so not only device value. So ASPM can have effect device in D3 power usage by having the switch the device is connect to powering down more by not sitting in a standby state waiting for commands from the CPU or worst full powered up state because its in performance mode.

      https://docs.fedoraproject.org/en-US...uide/ASPM.html
      powersave
      sets ASPM to save power wherever possible, regardless of the cost to performance.
      Devices does not have to be sleep or idle at powersave level the pcie switches can start staving power by turning off lans on D0.
      Linux does have another option powersupersave this can start powering down sections of the PCIe switch in the chipset and cpu when the lans are not need.

      https://en.wikipedia.org/wiki/Active...wer_Management
      Low power mode is often achieved by reducing or even stopping the serial bus clock as well as possibly powering down the PHY device itself.
      Yes this quote from the wikipedia you can confirm in the connected reference PDF but it written worse. A device can be in D3 because the PCIe switch has put it in D3 at ASPM direction to be correct D3 hot without in fact enabling s2idle. ASPM is relevant to devices in D3.

      Please note the PCIe switches hidden inside the system are not classed as PCIe devices so don't have a Dx number so are not power switched by setting s2idle. If your ASPM is sitting in performance or normal powersave instead of powersupersave when doing s2idle on a few laptops you will be up a few watts because the power will be eaten by the chipset/cpu pcie switch stuff not the device. Yes you can have some hidden ASPM rule saying keep the GPU nicely ready in performance mode.

      Setting the BIOS default in laptop for ASPM to performance instead of powersave or powersupersave can make a reviewer say laptop has better performance. Lot of reviewers don't check suspended battery life.

      Do note not all pcie switch designed used in CPU and chipsets are equally smart or foolish when it comes to ASPM stuff. Yes some designs of the ASPM bits in the pcie switches are going to responded more sanely to s2idle setting D3 to devices while ASPM is in performance mode but this is not required by PCIe specification.

      Yes the horrible undefined area of PCIe specification lead to some nice things where settings of ASPM is more important in some laptops than others for battery life.

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      • #13
        Originally posted by asriel View Post

        The issue is not with the desktops but with the laptops. Firstly majority of AMD laptop vendors removed S3 suspend in favor of s2idle modern standby. S3 works(not many AMD laptops support it), but with modern standby laptop pretends that it is suspended but big part of GPU continue eating battery like mad - 4-5 watts. For desktop it is nothing - you will not notice it, 4 watts desktop will be cool and quiet. But for laptop your battery will be gone in 5-10 hrs. So AMD issued the patch that stops the GPU completely and it does not eat battery when suspended - but in this case it does not wake up. So some kernels do not sleep , some do not wake up - depending on the patchsets in AMD GPU driver. There is some work and activity around this bug for more than half a year - but as I see it is not yet fixed. I got rid of my AMD laptop because of that and use Tigerlake now.
        Does your laptop have a dedicated GPU by any chance? I am not experiencing this with integrated GPU (4700U).

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        • #14
          Originally posted by asriel View Post

          The issue is not with the desktops but with the laptops. Firstly majority of AMD laptop vendors removed S3 suspend in favor of s2idle modern standby. S3 works(not many AMD laptops support it), but with modern standby laptop pretends that it is suspended but big part of GPU continue eating battery like mad - 4-5 watts. For desktop it is nothing - you will not notice it, 4 watts desktop will be cool and quiet. But for laptop your battery will be gone in 5-10 hrs. So AMD issued the patch that stops the GPU completely and it does not eat battery when suspended - but in this case it does not wake up. So some kernels do not sleep , some do not wake up - depending on the patchsets in AMD GPU driver. There is some work and activity around this bug for more than half a year - but as I see it is not yet fixed. I got rid of my AMD laptop because of that and use Tigerlake now.
          Sounds like a display driver issue, and a terrible one at that. I'm ambivalent about S2idle. On the one hand, my 5 year old HP Spectre x360 is plenty fast when it comes to suspend/resume, but on the other, I haven't experienced this "instant-on" mode yet so I don't know what it feels like. I ordered a new laptop not long ago (Tigerlake also) so we'll see if it's worth it. I would have went with AMD, but there are no premium laptops with AMD CPUs and integrated graphics. Looks like I dodged another bullet there.

          Originally posted by muncrief
          That was the excuse when I had my old R9 390 installed. But now I have two RX 580 GPUs, and no one says my GPU is too old any longer.
          You misunderstand. I'm not excusing AMD, whatever driver issues they may have. I'm only saying I don't experience this problem on my Ryzen 9 5900x/Radeon 6800 system. Just adding another data point to consider.

          Originally posted by theriddick
          I've had a ongoing issue with my 6800xt causing the lower quarter of the screen to tear after resume, even resume from xscreensaver oddly enough. Never happened on previous cards or under windows.. No idea if that will be fixed. It is related to having freesync enabled however. (which has never been great under Linux to be honest)
          Have you tried Wayland recently? It's a very nice experience, even when gaming (though I don't do much of that anymore)

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          • #15
            Originally posted by cynical View Post

            Have you tried Wayland recently? It's a very nice experience, even when gaming (though I don't do much of that anymore)
            I last tried it like a month-6wks back, and it still had some issues. Also I don't think it even supports freesync/vrr yet. Its still IMO at least a year or two away from being usable for a gamer/power desktop user.

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            • #16
              Originally posted by theriddick View Post
              I last tried it like a month-6wks back, and it still had some issues. Also I don't think it even supports freesync/vrr yet. Its still IMO at least a year or two away from being usable for a gamer/power desktop user.
              It really depends what wayland compositor you are talking about
              https://github.com/swaywm/wlroots/pull/1987

              If you were playing with a current version of sway 4 to 6 weeks back you would have had freesync/vrr support and its been present for over a year now.
              https://github.com/swaywm/sway/issues/5076

              But having that support is only half. "Automatic VRR management" is being tricky for everyone to implement. It does not help that EDID information is lacking some thing important. The speed that you can change HZ at.

              Some monitors if you change freesync/vrr speed too quickly they display tearing heck worse section of screen as technically stalled until the chip in the monitor self reboots. So I am not quite sure if you were seeing screen tearing in the GPU or a monitor chip crash and reboot. Yes this is sometimes fixed/overridden by altering VRR range. Yes some monitors with windows come with a driver disc where you don't install that you get the same kind of half screen tear you described under window for the same problem. Yes windows rate of change in vrr is different to the Linux one so you get some monitors that don't have a chip crash under windows but are crashing under Linux and the reverse..

              Freesync did not have the same mandated quality control as the Nvidia gsync and sometimes this really shows.

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              • #17
                Originally posted by oiaohm View Post


                Freesync did not have the same mandated quality control as the Nvidia gsync and sometimes this really shows.
                My monitor is flawless under windows with freesync, works fs, window, dual monitor config, fs range changes without issues... Linux has a quantum mile to go before it even comes close to how well it works under Windows.

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