[PATCH] ide_scsi: allow it to be used for non CD only

Some people want to use ide_cd for CD-ROM but still dynamically load
ide-scsi for things like tape drives. If you compile in the CD driver this
works out but if you want them modular you need an option to ensure that
whoever loads first the right things happen.

This replaces the original draft patch which leaked a scsi host reference

[[e-mail]: add MODULE_PARM_DESC]
Signed-off-by: Alan Cox <[e-mail]>
Cc: Bartlomiej Zolnierkiewicz <[e-mail]>
Cc: Jens Axboe <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/scsi/ide-scsi.c

···
 } idescsi_scsi_t;
 
 static DEFINE_MUTEX(idescsi_ref_mutex);
+static int idescsi_nocd;			/* Set by module param to skip cd */
 
 #define ide_scsi_g(disk) \
 	container_of((disk)->private_data, struct ide_scsi_obj, driver)
···
 		warned = 1;
 	}
 
+	if (idescsi_nocd && drive->media == ide_cdrom)
+		return -ENODEV;
+
 	if (!strstr("ide-scsi", drive->driver_req) ||
 	    !drive->present ||
 	    drive->media == ide_disk ||
···
 	driver_unregister(&idescsi_driver.gen_driver);
 }
 
+module_param(idescsi_nocd, int, 0600);
+MODULE_PARM_DESC(idescsi_nocd, "Disable handling of CD-ROMs so they may be driven by ide-cd");
 module_init(init_idescsi_module);
 module_exit(exit_idescsi_module);
 MODULE_LICENSE("GPL");