scsi_cmnd data_buffer checksum

From: Anil kumar
Date: Wed Sep 08 2010 - 23:43:39 EST



I am writing a checksum calculation of scsi_cmnd data buffer in the driver.

I calculate the checksum of the scsi_cmd data buffer(request_buffer) in driver queuecommand.

Now when the command is completed from the hardware and before driver sends it back to mid-layer, I calculate the checksum again of the same scsi_cmd data_buffer again.

Sometimes the checksums don't match. I mean somehow looks like OS changed the scsi_cmd data_buffer(request_buffer) in the meantime when driver is working on the command.
I print the address of the scsi_cmd data_buffer (virtual address) and its same and the contents of the buffer is also same during both the calculations.

Can this happen?




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