On Wed, Dec 10, 2014 at 01:04:58AM -0800, Darrick J. Wong wrote:
> On Wed, Dec 10, 2014 at 09:19:04AM +0100, Hans de Goede wrote:
> > Hi,
> >
> > On 09-12-14 20:31, Darrick J. Wong wrote:
> > >Hi,
> > >
> > >I have an Apricorn USB 3 disk dongle thing that claims to support UAS.
> > >However, the kernel crashes when I plug it in[1].
> >
> > Yes there are some known issues with uas error handling which are fixed
> > in 3.18, can you try with a 3.18 kernel please ?
>
> The crash pic was from 3.18.0, blk_mq disabled. I'll work on getting a fuller
> dmesg output. Looking at the code, it looks like we end up in
> queue_bulk_sg_tx() with a sg list that is shorter than num_sgs, so we fall off
> the end.
>
> (Alas it's now 1am here, so I'm going to bed. :/ )
Eh, nuts to sleeping. dmesg produces this:
[ 231.128074] usbcore: registered new interface driver usb-storage
[ 231.133822] usbcore: registered new interface driver uas
[ 252.121353] usb 2-4: new SuperSpeed USB device number 2 using xhci_hcd
[ 252.136927] scsi host6: uas
[ 252.141679] scsi 6:0:0:0: Direct-Access Apricorn 0128 PQ: 0 ANSI: 6
[ 252.145433] sd 6:0:0:0: Attached scsi generic sg2 type 0
[ 252.145525] sd 6:0:0:0: [sdc] 312581808 512-byte logical blocks: (160 GB/149 GiB)
[ 252.145527] sd 6:0:0:0: [sdc] 4096-byte physical blocks
[ 252.145891] sd 6:0:0:0: [sdc] Write Protect is off
[ 252.145973] sd 6:0:0:0: [sdc] No Caching mode page found
[ 252.145975] sd 6:0:0:0: [sdc] Assuming drive cache: write through
[ 252.171739] queue_bulk_sg_tx: num=4294967295 sg=ffff8804584e0b00 addr= (null) len=0 pagelink=116b8882
[ 252.173706] queue_bulk_sg_tx: num=4294967295 sg= (null), ABORT
<KABOOM>
I wrote in a printk to spit out num_sgs and some of the sg data right before
the sg_next() call. Looks like num_sgs is originally zero? I then patched
the code to break early if num_sgs == 0:
/* Calculate length for next transfer --
* Are we done queueing all the TRBs for this sg entry?
*/
this_sg_len -= trb_buff_len;
printk(KERN_ERR "%s: num=%u sg=%p addr=%lx len=%u pagelink=%lx\n", __func__, num_sgs, sg, addr, this_sg_len, sg->page_link);
if (this_sg_len == 0) {
if (num_sgs == 0) {
printk(KERN_ERR "%s: breaking early, no sgs??\n", __func__);
break;
}
--num_sgs;
if (num_sgs == 0)
break;
sg = sg_next(sg);
addr = (u64) sg_dma_address(sg);
this_sg_len = sg_dma_len(sg);
This produced this log[1] which I've excerpted here:
[ 96.944791] usb 2-4: new SuperSpeed USB device number 2 using xhci_hcd
[ 96.972881] usbcore: registered new interface driver usb-storage
[ 128.315902] scsi host6: uas
[ 128.318605] usbcore: registered new interface driver uas
[ 128.318691] queue_bulk_sg_tx: num=1 sg=ffff88044650ed00 addr=446958000 len=0 pagelink=ffffea00111a5602
[ 128.318960] queue_bulk_sg_tx: num=1 sg=ffff880457a03300 addr=446958000 len=0 pagelink=ffffea00111a5602
[ 128.321144] scsi 6:0:0:0: Direct-Access Apricorn 0128 PQ: 0 ANSI: 6
[ 128.321165] queue_bulk_sg_tx: num=1 sg=ffff880457a03300 addr=45cbb1000 len=0 pagelink=ffffea001172ec42
[ 128.323714] queue_bulk_sg_tx: num=1 sg=ffff880457a02100 addr=447738000 len=0 pagelink=ffffea00111dce02
[ 128.326233] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=45a4c8000 len=0 pagelink=ffffea0011693202
[ 128.329157] sd 6:0:0:0: Attached scsi generic sg2 type 0
[ 128.331328] queue_bulk_sg_tx: num=1 sg=ffff88045795ce00 addr=456ad7000 len=0 pagelink=ffffea00115ab5c2
[ 128.331428] sd 6:0:0:0: [sdc] 312581808 512-byte logical blocks: (160 GB/149 GiB)
[ 128.331431] sd 6:0:0:0: [sdc] 4096-byte physical blocks
[ 128.331448] queue_bulk_sg_tx: num=1 sg=ffff880457a02100 addr=456ad7000 len=0 pagelink=ffffea00115ab5c2
[ 128.333772] queue_bulk_sg_tx: num=1 sg=ffff880457a03300 addr=44649e000 len=0 pagelink=ffffea0011192782
[ 128.336191] queue_bulk_sg_tx: num=1 sg=ffff880457a02700 addr=45683b000 len=0 pagelink=ffffea00115a0ec2
[ 128.338561] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=37355000 len=0 pagelink=ffffea0000dcd542
[ 128.340979] queue_bulk_sg_tx: num=1 sg=ffff880457a02c00 addr=8a8e3000 len=0 pagelink=ffffea00022a38c2
[ 128.343246] sd 6:0:0:0: [sdc] Write Protect is off
[ 128.343263] queue_bulk_sg_tx: num=1 sg=ffff880457a02400 addr=8a8e2000 len=0 pagelink=ffffea00022a3882
[ 128.345461] sd 6:0:0:0: [sdc] No Caching mode page found
[ 128.345463] sd 6:0:0:0: [sdc] Assuming drive cache: write through
[ 128.345475] queue_bulk_sg_tx: num=1 sg=ffff880457a02000 addr=45ba6ba00 len=0 pagelink=ffffea00116e9ac2
[ 128.347752] queue_bulk_sg_tx: num=1 sg=ffff880457a02000 addr=8ab21000 len=0 pagelink=ffffea00022ac842
[ 128.352127] queue_bulk_sg_tx: num=1 sg=ffff880457a02c00 addr=8637f000 len=0 pagelink=ffffea000218dfc2
[ 128.354225] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=8637e000 len=0 pagelink=ffffea000218df82
[ 128.356278] queue_bulk_sg_tx: num=1 sg=ffff880457a02700 addr=8a8b7000 len=0 pagelink=ffffea00022a2dc2
[ 128.358325] queue_bulk_sg_tx: num=1 sg=ffff880457a03300 addr=8a8b6000 len=0 pagelink=ffffea00022a2d82
[ 128.360450] queue_bulk_sg_tx: num=1 sg=ffff880457a02100 addr=8a8b1000 len=0 pagelink=ffffea00022a2c42
[ 128.362443] queue_bulk_sg_tx: num=1 sg=ffff880457a02100 addr=8a8b0000 len=0 pagelink=ffffea00022a2c02
[ 128.364448] queue_bulk_sg_tx: num=1 sg=ffff880457a03300 addr=84d55000 len=0 pagelink=ffffea0002135542
[ 128.366488] queue_bulk_sg_tx: num=1 sg=ffff880457a02700 addr=84d54000 len=0 pagelink=ffffea0002135502
[ 128.368545] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=863bd000 len=0 pagelink=ffffea000218ef42
[ 128.732280] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=37182000 len=0 pagelink=ffffea0000dc6082
[ 128.734945] queue_bulk_sg_tx: num=1 sg=ffff880457a02600 addr=3718200d len=499 pagelink=ffffea0000dc6082
[ 128.737631] queue_bulk_sg_tx: num=0 sg=ffff880457a02600 addr=0 len=0 pagelink=ffffea0000dc6082
[ 128.740150] queue_bulk_sg_tx: breaking early, no sgs??
[ 128.742665] usb 2-4: check_trb_math - ep 0x8b - Miscalculated number of TRBs, -1 left
[ 159.618522] sd 6:0:0:0: [sdc] uas_eh_abort_handler 0 tag 1 inflight: IN
[ 159.620287] sd 6:0:0:0: [sdc] CDB:
[ 159.622016] Read(10): 28 00 00 00 00 0f 00 00 00 00
[ 159.624014] scsi host6: uas_eh_bus_reset_handler start
[ 159.728110] usb 2-4: reset SuperSpeed USB device number 2 using xhci_hcd
In the full log, you can at time 192.488278 that we got all jammed up in the sd
probe trying to read a disklabel off the drive. I'm suspicious of those last
two queue_bulk_sg_tx printks since it seems awfully coincidental that it gets
called twice, once with a sane looking addr and length, then again with the
same sg and page_link yet the addr and num_sgs have become zero.
(Ok, now I'm really going to bed.)
--D
[1] http://djwong.org/docs/bad2.txt
>
> --D
>
> >
> > Note that the device will likely still not work, but it should no
> > longer crash things. When running 3.18 please collect the output of
> > "dmesg" after plugging in the drive and send that to me, then we'll see
> > if we can get it to work from there.
> >
> > Regards,
> >
> > Hans
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