Description of problem:
I have so called Digi Box, ProCaster PVR-6500 for receiving digital TV broadcasting (using analog TV). In ProCaster there is a 500GB HDD for saving received programs and a USB 2 connector for transfer saved files to computer. With Windows XP and Windows 7 USB file transfer works OK.

Using Fedora 17 following happens:
After ProCaster is cold started, plugin USB to PC shows mount menu in Gnome and HDD can be mounted. Mount succeeds and file transfer works OK. Also unmount and remount work OK. I saved a trace of USB communication and there is seen that Get Max LUN function is used and response to that is 0x00.

But if ProCaster HDD is unmouned and USB is disconnected, the second try to plugin of the USB cable to Fedora does nothing. No mount prompt is presented in Gnome. In USB trace is shown, that respose to Get Max LUN function is now 0x7F.
This is probably the reason of the problem. udev does not create /dev/sdx1 (eg /dev/sdb1) device entry. The only way to get the USB connection to ProCaster to work again, is to shut down it, unplug the power cable of it and then restart. After that the first time of USB cable plugin it works again. After unmount and unplug, replugin does not work anymore.

The HDD in ProCaster is a single partition vfat formatted disk and uses Cypress Semiconductor interface.

Output of lsusb says:
Bus 002 Device 006: ID 04b4:6830 Cypress Semiconductor Corp. CY7C68300A EZ-USB AT2 USB 2.0 to ATA/ATAPI


Version-Release number of selected component (if applicable):
Kernel 3.6.8-2.fc17.x86_64, probably also earlier versions


How reproducible:
One should have a ProCaster PVR-6500... Not very usual device, probably sold mainly in Finland


Steps to Reproduce:
1.Cold start ProCaster
2.Plugin USB
3.Mount the disk
4. Transfer some files
5. unmount and unplug USB
6. plugin USB again
7. Now it is unable to mount, block device is not created
  
Actual results:
Mount stops working at step 6.


Expected results:
One should be able to mount the disc after replugin

Additional info:
The actual bug is probably in ProCaster SW.
Changing 04b4:6380 entry in unusual_cypress.h by adding US_FL_SINGLE_LUN seems to solve this problem, but could it generate problems with other devices?

Replacing present entry of 04b4:6380 with
UNUSUAL_DEV(  0x04b4, 0x6830, 0x0000, 0x9999,
                "Cypress",
                "Cypress AT2LP",
                USB_SC_SCSI, USB_PR_BULK, NULL,
                US_FL_SINGLE_LUN ),

or changing present entry to
UNUSUAL_DEV(  0x04b4, 0x6830, 0x0000, 0x9999,
                "Cypress",
                "Cypress AT2LP",
                USB_SC_CYP_ATACB, USB_PR_DEVICE, NULL, 0|US_FL_SINGLE_LUN),
both seem to solve the problem.



Some commented kernel and usb logs and lsusb as attachment.