SG_IO v3 "ATA IDENTIFY DEVICE" command from ata_id hoses bridge

[Tormod Volden]

I have Ubuntu 12.04 installed on an external hard drive, where the disk enclosure has a Cypress CY7C68300A EZ-USB AT2 USB 2.0 to ATA/ATAPI bridge.

At boot, the udev rules probes the drive with /lib/udev/ata_id and this makes the bridge lock up and the disk unavailable. After 30 seconds a scsi reset is issued and the drive comes back. I have traced this down to the "v3" fallback of extras/ata_id/ata_id.c:187. When patching this ioctl away everything is fine.

Another workaround would be to change the udev rules to not call ata_id when this particular bridge is detected. ata_id does not return anything for this drive on my setup anyway.

lsusb:
Bus 002 Device 003: ID 04b4:6830 Cypress Semiconductor Corp. CY7C68300A EZ-USB AT2 USB 2.0 to ATA/ATAPI

[Tormod Volden (tormodvolden)]

BTW, (with or without my patch) runnig ata_id on my drive makes udev log this:
ata_id[5678]: HDIO_GET_IDENTITY failed for '/dev/sdb': Invalid argument

[Tormod Volden (tormodvolden)]

So this is what ata_id is up to:

disk_scsi_inquiry_command trying v4
disk_scsi_inquiry_command trying v3
disk_identify_command trying v4
disk_identify_command trying v3
 *the latter sends 0xEC via cypress_atacb.c and it hangs
main trying HDIO_GET_IDENTITY
 *that fails with "Invalid argument"

I found out that my hdparm trouble in bug #428469 is caused by the same atacb commands. I have been using "nohdparm" for years.

[Tormod Volden (tormodvolden)]

debug from drivers/usb/storage/transport.c

 [ 166.745112] cypress_atacb.c sending command ec
 [ 166.745117] usb-storage: Bulk Command S 0x43425355 T 0x16 L 512 F 128 Trg 0 LUN 0 CL 16
 [ 166.745120] usb-storage: usb_stor_bulk_transfer_buf: xfer 31 bytes
 [ 166.745196] usb-storage: Status code 0; transferred 31/31
 [ 166.745199] usb-storage: -- transfer complete
 [ 166.745202] usb-storage: Bulk command transfer result=0
 [ 166.745205] usb-storage: usb_stor_bulk_transfer_sglist: xfer 512 bytes, 1 entries
 [ 166.745318] usb-storage: Status code -121; transferred 13/512
 [ 166.745321] usb-storage: -- short read transfer
 [ 166.745324] usb-storage: Bulk data transfer result 0x1
 [ 166.745326] usb-storage: Attempting to get CSW...
 [ 166.745329] usb-storage: usb_stor_bulk_transfer_buf: xfer 13 bytes
 [ 197.549055] usb-storage: usb_stor_stop_transport called
 [ 197.549059] usb-storage: -- cancelling URB
 [ 197.549181] usb-storage: Status code -104; transferred 0/13
 [ 197.549184] usb-storage: -- transfer cancelled
 [ 197.549187] usb-storage: Bulk status result = 4
 [ 197.549190] us->transport returned 0x03
 [ 197.549192] usb-storage: -- command was aborted
 [ 197.621166] usb 1-1.1: reset high-speed USB device number 6 using ehci_hcd