"add_drv/rem_drv currently busy; try later"

Question

I am writing a device driver for PCI card on intel /x86 p/f Solaris 8.
I have succefully written some portion of the driver & is able to read from
the device register.Now i had to initialize the DMA in BUS master mode residing on
my device.For that i had called the following routines in attach(9E) entry
point.
     1)ddi_dma_alloc_handle();
     2)di_dma_mem_alloc();
     3)di_dma_addr_bind_handle();
     I succefully complied the code.
MY PROBLEM IS:-     
     1) when i attach my device driver to the system using add_drv -i command ,
the system get hanged & reboots after sometime.While at booting it shows that the system hanged because of ddi_dma_alloc_handle() function.The system never boots up while the PCI device is plugged to the system.Now i remove the PCI device from the system & the system boots up perfectly.NOW I TRY TO REMOVE THE DRIVER FOR THAT PCI DEVICE:-
using "rem_drv" command BUT SYSTEM SHOWS FOLLOWING MESSAGE:-
          "add_drv/rem_drv currently busy; try later"
          How to overcome this problem??????if anyone can help??i will be grateful to him.
2)With what value the ddi_dma_attr(9s) structure will be initialized for PCI bus device.     
Kindly help.
Thanks in advance               

Answer 1

Try:
/usr/bin/rm /tmp/AdDrEm.lck
MM