(no subject)

[Jim Zeus <zeusj@firstlinux.net>]

Hi ,folks 
 
I am reading MTD code now , and I meet some problem

in the /drivers/mtd/chips/cfi_probe.c 

	/* Check each previous chip to see if it's an alias */
	for (i=0; i<cfi->numchips; i++) {
		/* This chip should be in read mode if it's one
		   we've already touched. */
		if (qry_present(map,chips[i].start,cfi)) {
			/* Eep. This chip also had the QRY marker. 
			 * Is it an alias for the new one? */
			cfi_send_gen_cmd(0xF0, 0, chips[i].start, map, cfi, cfi->device_type, NULL);

			/* If the QRY marker goes away, it's an alias */
			if (!qry_present(map, chips[i].start, cfi)) {
				printk(KERN_DEBUG "%s: Found an alias at 0x%x for the chip at 0x%lx\n",
				       map->name, base, chips[i].start);
				return 0;

/*******I have no idea that the following query command for*******/
/**********I think it will never happen*******************/}
			/* Yes, it's actually got QRY for data. Most 
			 * unfortunate. Stick the new chip in read mode
			 * too and if it's the same, assume it's an alias. */
			/* FIXME: Use other modes to do a proper check */
			cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
			
			if (qry_present(map, base, cfi)) {
				printk(KERN_DEBUG "%s: Found an alias at 0x%x for the chip at 0x%lx\n",
				       map->name, base, chips[i].start);
				return 0;
			} 
		}
	}
	


from the code I deduce that 
1. if send the query command twice , the "QRY" will disappear.
2. if send the query command onec, the "QRY" will always be there even you read it many times.
Is my conclusion right?
I know its a stupid question to hardware engineer, but I am a software engineer:<

Any help will be appreciated.


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