[linux-usb-devel] [Fwd: USB 2.0 HDD Walker / ST-HW-818SLIM usb-storage fix]

[Roger Crettol]

Hello there !

Below ist the story - in the attachment is a diff that's more like a
real patch. Thanks for making it so easy to fix.

-rg-

--- Begin Message --- Hello !

This is to announce a modest but decisive success in connecting some 20/30GB USB 2.0 mass storage devices under Linux 2.4.

The devices are (built ?) and marketed under the brand HDD Walker / ST-HW-818 slim by a taiwanese company, St. John Technology Co., Ltd. The product I bought didn't carry a manufacturer identification, neither did the accompanying CD-ROM with drivers for Mac and various Windows flavours.
But he name ST-HW-818 appears on the CD-ROM as a directory name, which lead to the probable identification of the manufacturer.

The device identifies itself on the USB bus as :

lizzard ## lsusb -v -s 1:2
Bus 001 Device 002: ID 05e3:0702 Genesys Logic, Inc.
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 Interface
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0        64
  idVendor           0x05e3 Genesys Logic, Inc.
  idProduct          0x0702
  bcdDevice            0.02
  iManufacturer           0
  iProduct                1 USB TO IDE
  iSerial                 0
  bNumConfigurations      1

and wouldn't let the scsi layer read the partition table. under any kernel releases I've tried :
2.4.18, 2.4.19, 2.4.19-ac4, 2.4.20-pre7, 2.4.20-pre7-ac4.

I then discussed this with my brother and he suggested tinkering with the file unusual_devs.h in /usr/src/linux/drivers/usb/storage, which has an entry for 0x05e3:0x0702. Since this device is now at release level 0.02, I thought of getting rid of US_FL_FIX_INQUIRY first, to see what the device may tell about itself - and this single action turned a piece of uncooperative equipment into a happily operating disk drive ... high return on investment, and a big many thanks to the USB developers.

This is now the modified section of the unusual_devs.h file I've used to compile the usb-storage module :
/*
        ST818slim drives dont' need special care anymore
UNUSUAL_DEV(  0x05e3, 0x0702, 0x0000, 0xffff,
                "EagleTec",
                "External Hard Disk",
                US_SC_SCSI, US_PR_BULK, NULL,
                US_FL_FIX_INQUIRY ),
*/

Hope this may help anyone with a similar drive.

-rg- --- End Message ---

--- linux-2.4.20-ac3/drivers/usb/storage/unusual_devs.h Wed Sep 25 08:43:54 2002
+++ linux-2.4.20-ac3-fix/drivers/usb/storage/unusual_devs.h     Wed Sep 25 08:20:26 
+2002
@@ -333,8 +333,10 @@
  * Like the SIIG unit above, this unit needs an INQUIRY to ask for exactly
  * 36 bytes of data.  No more, no less. That is the only reason this entry
  * is needed.
- */
-UNUSUAL_DEV(  0x05e3, 0x0702, 0x0000, 0xffff,
+ *
+ * ST818 slim drives (rev 0.02) don't need special care.
+*/
+UNUSUAL_DEV(  0x05e3, 0x0702, 0x0000, 0x0001,
                "EagleTec",
                "External Hard Disk",
                US_SC_SCSI, US_PR_BULK, NULL,