2009-04-06 09:53:51

by Yu-Ming Chang 張育銘

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Subject: The kernel may clear part of my vendor-specific SCSI command.

Dear Linux developers,

I'm using CentOS 5.2(kernel-2.6.18) to control a specific USB massive
storage
device. When I send a vendor-spcific SCSI command to the device like this:

unsigned char scsi_cmd[16];
sg_io_hdr_t io_hdr;
scsi_cmd[0] = 0xf1;
scsi_cmd[1] = 0xff;
io_hdr.cmdp = scsi_cmd;

the device receives a command with scsi_cmd[1] = 0x1f. I think the first
of three
bits of second byte of io_hdr.cmdp are cleared by kernel.

Does anyone have some clues or hints?
I wish you can CC to my mailbox when you respond to my posting.

Regards,
Chang Yu-ming