On Sat, 17 Mar 2018, Benjamin Herrenschmidt wrote: > On Fri, 2018-03-16 at 16:56 -0400, Alan Stern wrote: > > On Fri, 16 Mar 2018, Benjamin Herrenschmidt wrote: > > > > > On Thu, 2018-03-15 at 08:03 +1100, Benjamin Herrenschmidt wrote: > > > > > > Do you have more comments for the rest of the driver or that's it ? > > > > > > > > > > so far, that's it. > > > > > > > > Ok. I'll re-send. > > > > > > So I'll resend in a minute, doing a few more tests, however, I've > > > noticed something which I wont' have time to track down til at > > > best next week, I wonder if it's normal/expected. > > > > > > If I just create a mass storage function set to be "removable" and > > > "cdrom" with no file attached, and enable it, I get an endless stream > > > of resets. It looks like the host constantly does USB resets. > > > > That's not why I get. There's an endless stream of messages, but it > > doesn't include any resets. Just command failures and endpoint halts. > > For example: > > .../... > > In my case, I was getting resets on the host: > > [383250.844611] usb 1-1: new high-speed USB device number 84 using xhci_hcd > [383250.972235] usb 1-1: New USB device found, idVendor=1d6b, idProduct=0107 > [383250.972244] usb 1-1: New USB device strings: Mfr=3, Product=2, SerialNumber=1 > [383250.972251] usb 1-1: Product: USB Virtual Hub > [383250.972257] usb 1-1: Manufacturer: Aspeed > [383250.972262] usb 1-1: SerialNumber: 00000000 > [383250.979127] hub 1-1:1.0: USB hub found > [383250.979218] hub 1-1:1.0: 5 ports detected > [383284.910195] usb 1-1.1: new high-speed USB device number 85 using xhci_hcd > [383284.988326] usb 1-1.1: New USB device found, idVendor=1d6b, idProduct=0104 > [383284.988339] usb 1-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 > [383284.988349] usb 1-1.1: Product: Bar Gadget > [383284.988358] usb 1-1.1: Manufacturer: Foo Inc. > [383284.988366] usb 1-1.1: SerialNumber: 0123456789 > [383285.000159] usb-storage 1-1.1:1.0: USB Mass Storage device detected > [383285.000613] scsi host3: usb-storage 1-1.1:1.0 > [383286.063152] scsi 3:0:0:0: CD-ROM Linux File-CD Gadget 0416 PQ: 0 ANSI: 2 > [383286.064148] sr 3:0:0:0: Power-on or device reset occurred > [383286.129411] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383286.284397] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383286.438396] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383286.593487] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383286.676863] sr 3:0:0:0: [sr0] scsi-1 drive > [383286.676871] cdrom: Uniform CD-ROM driver Revision: 3.20 > [383286.678558] sr 3:0:0:0: Attached scsi CD-ROM sr0 > [383286.679426] sr 3:0:0:0: Attached scsi generic sg2 type 5 > [383286.746343] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383286.901458] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383287.056423] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383287.211445] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383287.360422] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383287.516295] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383287.671464] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383287.827423] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > [383287.912048] sr 3:0:0:0: Power-on or device reset occurred > [383288.013376] usb 1-1.1: reset high-speed USB device number 85 using xhci_hcd > > The guest just show config selection messages. I'll dig a bit next week > in case there's an issue with my UDC driver there. Output from usbmon could help. > As for ... > > > It's worth pointing out that all those messages are at DEBUG level. > > Although they fill up the kernel's log buffer, they won't be noticeable > > to most users. > > > > In any case, g-mass-storage was never intended be a complete emulation > > of a CD or DVD drive. Its support for those modes is minimal; it was > > originally intended just to emulate a hard disk drive. > > Then it will be worthwhile me or somebody else spending a bit of time > beefing it up a little bit. I'll see if I can spare time in the next > couple of weeks. Maybe... Even after cdrom support was added to the gadget, the scope was limited. It was intended to emulate _only_ a CD drive, not a DVD drive. Also, if I'm not mistaken, the commands that the emulation doesn't handle are all optional. Alan Stern > The Aspeed chip is a BMC chip, ie server management processor, and is > connected via the USB gadget to the actual server (the host). One of > the usage scenario here is to use USB gadget to present distro ISOs as > USB CD/DVDs to the host for remote provisioning (sourced over the > network via something like nbd). > > Note that due to the limitation of having to use a file or a block > device, we might end up doing a userspace CDROM emulation instead that > can source ISOs via things like HTTPS instead, but initially the above > is what we are toying with. > > Cheers, > Ben. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
