On Thu, 30 Apr 2020, Vladimir Stankovic wrote: > On 30.4.20. 17:18, Alan Stern wrote: > > On Thu, 30 Apr 2020, Vladimir Stankovic wrote: > > > >> On 26.4.20. 22:56, Alan Stern wrote: > >>> On Sun, 26 Apr 2020, Vladimir Stankovic wrote: > >>> > >>>> On 26.4.20. 16:31, Alan Stern wrote: > >>>>> On Sun, 26 Apr 2020, Vladimir Stankovic wrote: > >>>>> > >>>>>> On 26.4.20. 02:32, Alan Stern wrote: > >>>>>>> On Sat, 25 Apr 2020 vladimir.stankovic@xxxxxxxxxxxxxxx wrote: > >>>>>>> > >>>>>>>> Protocol adaptation layer (PAL) implementation has been added to > >>>>>>>> introduce MA-USB structures and logic. > >>>>>>>> > >>>>>>>> Signed-off-by: Vladimir Stankovic <vladimir.stankovic@xxxxxxxxxxxxxxx> > >>>>>>> > >>>>>>> ... > >>>>>>> > >>>>>>>> + /* > >>>>>>>> + * Masking URB_SHORT_NOT_OK flag as SCSI driver is adding it where it > >>>>>>>> + * should not, so it is breaking the USB drive on the linux > >>>>>>>> + */ > >>>>>>>> + urb->transfer_flags &= ~URB_SHORT_NOT_OK; > > > > ... > > Also, what makes you think the driver is setting the SHORT_NOT_OK flag > > at the wrong time? In fact, how can there be a wrong time? > > SHORT_NOT_OK is a valid flag to use with any control or bulk URB. > > > > Alan Stern > > > The comment is clearly wrong - as mentioned earlier, this fix was added in early > development phase and I guess that implementer was not clear on how the particular > flag was added. Investigation is ongoing around proper fix for this. > > Anyhow, it is a usb-storage driver related to this - here is usb-related log snippet: > > usb 3-1.1.2: new high-speed USB device number 5 using mausb_host_hcd_dev > usb 3-1.1.2: New USB device found, idVendor=0951, idProduct=1666 > usb 3-1.1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3 > usb 3-1.1.2: Product: DataTraveler 3.0 > usb 3-1.1.2: Manufacturer: Kingston > usb 3-1.1.2: SerialNumber: 0C9D9210E304E311095E087A > usb-storage 3-1.1.2:1.0: USB Mass Storage device detected > scsi host3: usb-storage 3-1.1.2:1.0 > scsi 3:0:0:0: Direct-Access Kingston DataTraveler 3.0 PMAP PQ: 0 ANSI: 6 > Attached scsi generic sg2 type 0 > [sdb] 30277632 512-byte logical blocks: (15.5 GB/14.4 GiB) > > As can be seen, USB flash attached to remote device is properly enumerated via > MA USB. Without the fix, usb driver is not able to read USB descriptors, ending > up in USB storage not being accessible. That's strange, considering that the SHORT_NOT_OK flag doesn't get set when the system is reading the device's USB descriptors. Alan Stern
