On 18 Feb 2019, Johan Hovold stated: > On Sun, Feb 17, 2019 at 07:13:52PM +0000, Nix wrote: >> I'm still fairly sure this is a regression -- my machines are often up >> for a lot longer than that and I've never seen this before I upgraded to >> 4.20.x -- but I don't think I'm going to identify it by mindless >> bisection. I might have to actually *think* about it. > > I doubt it's a regression in usb-serial as essentially nothing changed > with respect to pl2303 or core since 4.19. Yeah, I came to that conclusion as well. > The -ENOSPC you're seeing is returned by the host controller to > indicate: > > This request would overcommit the usb bandwidth reserved for > periodic transfers (interrupt, isochronous). Side note: probably not related to *this* -ENOSPC, which I've been seeing for a few releases now and which appears to break Chromium's U2F negotiation when the USB bus has sufficiently weird devices on it (like, uh, my wireless mouse): <https://bugs.chromium.org/p/chromium/issues/detail?id=932699> (I say "probably not related" because it's much older and long predates the pl2303 trouble.) > but if you're saying you can reproduce this on "every box" it may not be > related to any particular host-controller driver (or USB topology). They are all xhci, at least. The pl2303 is USB 2. One machine, a two-year-old Broadwell server, says: xhci_hcd 0000:00:14.0: xHCI Host Controller xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 3 xhci_hcd 0000:00:14.0: hcc params 0x200077c1 hci version 0x100 quirks 0x0000000000009810 xhci_hcd 0000:00:14.0: cache line size of 32 is not supported hub 3-0:1.0: USB hub found hub 3-0:1.0: 15 ports detected xhci_hcd 0000:00:14.0: xHCI Host Controller xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 4 xhci_hcd 0000:00:14.0: Host supports USB 3.0 SuperSpeed 00:14.0 USB controller: Intel Corporation C610/X99 series chipset USB xHCI Host Controller (rev 05) (prog-if 30 [XHCI]) The other, a 2012-era cheapish Ivy Bridge workstation: xhci_hcd 0000:03:00.0: xHCI Host Controller xhci_hcd 0000:03:00.0: new USB bus registered, assigned bus number 3 xhci_hcd 0000:03:00.0: hcc params 0x014042cb hci version 0x96 quirks 0x0000000000000004 hub 3-0:1.0: USB hub found hub 3-0:1.0: 2 ports detected xhci_hcd 0000:03:00.0: xHCI Host Controller xhci_hcd 0000:03:00.0: new USB bus registered, assigned bus number 4 xhci_hcd 0000:03:00.0: Host supports USB 3.0 SuperSpeed usb usb4: We don't know the algorithms for LPM for this host, disabling LPM. hub 4-0:1.0: USB hub found hub 4-0:1.0: 2 ports detected xhci_hcd 0000:04:00.0: xHCI Host Controller xhci_hcd 0000:04:00.0: new USB bus registered, assigned bus number 5 xhci_hcd 0000:04:00.0: hcc params 0x0200f180 hci version 0x96 quirks 0x0000000000080000 hub 5-0:1.0: USB hub found hub 5-0:1.0: 2 ports detected xhci_hcd 0000:04:00.0: xHCI Host Controller xhci_hcd 0000:04:00.0: new USB bus registered, assigned bus number 6 xhci_hcd 0000:04:00.0: Host supports USB 3.0 SuperSpeed usb usb6: We don't know the algorithms for LPM for this host, disabling LPM. 03:00.0 USB controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 03) (prog-if 30 [XHCI]) 04:00.0 USB controller: ASMedia Technology Inc. ASM1042 SuperSpeed USB Host Controller (prog-if 30 [XHCI]) (I really don't know which of these is which. I suspect only one actually has any visible ports on the outside of the case...) So the quirks are all totally different, and the controllers are quite different as well...
