On Mon, Nov 23, 2020 at 02:54:19PM +0100, Hans de Goede wrote: > Hi, > > On 11/11/20 3:31 PM, Mika Westerberg wrote: > > On Wed, Nov 11, 2020 at 12:27:32PM +0100, Hans de Goede wrote: > >> Hi, > >> > >> On 11/10/20 6:25 PM, Mika Westerberg wrote: > >>> On Tue, Nov 10, 2020 at 04:02:33PM +0000, Limonciello, Mario wrote: > >>>>> > >>>>> On Tue, Nov 10, 2020 at 11:57:07AM +0100, Bastien Nocera wrote: > >>>>>> Hey, > >>>>>> > >>>>>> systemd has been shipping this script to enable auto-suspend on a > >>>>>> number of USB and PCI devices: > >>>>>> > >>>>> https://github.com/systemd/systemd/blob/master/tools/chromiumos/gen_autosuspen > >>>>> d_rules.py > >>>>>> > >>>>>> The problem here is twofold. First, the list of devices is updated from > >>>>>> ChromeOS, and the original list obviously won't be updated by ChromeOS > >>>>>> developers unless a device listed exists in a ChromeBook computer, > >>>>>> which means a number of devices that do support autosuspend aren't > >>>>>> listed. > >>>>>> > >>>>>> The other problem is that this list needs to exist at all, and that it > >>>>>> doesn't seem possible for device driver developers (at various levels > >>>>>> of the stack) to opt-in to auto-suspend when all the variants of the > >>>>>> device (or at least detectable ones) support auto-suspend. > >>>>> > >>>>> A driver can say they support autosuspend today, but I think you are > >>>>> concerned about the devices that are controlled by class-compliant > >>>>> drivers, right? And for those, no, we can't do this in the kernel as > >>>>> there are just too many broken devices out there. > >>>>> > >>>> > >>>> I guess what Bastien is getting at is for newer devices supported by class > >>>> drivers rather than having to store an allowlist in udev rules, can we set > >>>> the allowlist in the kernel instead. Then distributions that either don't > >>>> use systemd or don't regularly update udev rules from systemd can take > >>>> advantage of better defaults on modern hardware. > >>>> > >>>> The one item that stood out to me in that rules file was 8086:a0ed. > >>>> It's listed as "Volteer XHCI", but that same device ID is actually present > >>>> in an XPS 9310 in front of me as well and used by the xhci-pci kernel module. > >>>> > >>>> Given we're effectively ending up with the combination of runtime PM turned > >>>> on by udev rules, do we need something like this for that ID: > >>>> > >>>> https://github.com/torvalds/linux/commit/6a7c533d4a1854f54901a065d8c672e890400d8a > >>>> > >>>> @Mika Westerberg should 8086:a0ed be quirked like the TCSS xHCI too? > >>> > >>> I think this one is the TGL PCH xHCI. The quirk currently for xHCI > >>> controllers that are part of the TCSS (Type-C SubSystem) where it is > >>> important to put all devices into low power mode whenever possible, > >>> otherwise it keeps the whole block on. > >> > >> Note that there are currently some IDs missing from the xHCIs which > >> are part of the TCSS too. At least the id for the xHCI in the thunderbolt > >> controller on the Lenovo T14 gen 1 is missing. I started a discussion > >> about extending the kernel quirk list for this vs switching to hwdb > >> a while a go: > >> > >> https://lore.kernel.org/linux-usb/b8b21ba3-0a8a-ff54-5e12-cf8960651086@xxxxxxxxxx/ > >> > >> The conclusion back then was to switch to hwdb, but I never got around to this. > > > > The reason I've added these to the xHCI driver is that it works even if > > you are running some really small userspace (like busybox). Also for the > > xHCI in TCSS we know for sure that it fully supports D3cold. > > > > (The one you refer above is actually mistake from my side as I never > > tested Alpine Ridge LP controller which I think this is). > > Ok, so I'll submit a patch adding the 15c1 product-id for the > INTEL_ALPINE_RIDGE_LP_2C_XHCI controller to the list of ids for which we > set the XHCI_DEFAULT_PM_RUNTIME_ALLOW quirk. To fix the much too high > idle-power consumption problem on devices with this Alpine Ridge variant. Thanks!
