Re: [PATCH] support HDIO_GET_IDENTITY in libata

[Jeff Garzik <jeff@garzik.org>]

Alexey Dobriyan wrote:
> On Thu, Dec 14, 2006 at 01:26:08PM -0700, Erik Andersen wrote:
>> On Thu Dec 14, 2006 at 03:05:52PM -0500, Jeff Garzik wrote:
>>> FWIW, libata generally follows a "implement it, if enough people care
>>> about it" policy for the old HDIO_xxx ioctls.
>> I personally care about HDIO_GET_IDENTITY and find it terribly
>> useful to quickly find out about a drive.  Perhaps enough other
>> people care about this ioctl that it might make it into the official
>> libata tree.  Well tested with a number of months of use.
> 
>> --- orig/drivers/ata/libata-scsi.c
>> +++ linux-2.6.18/drivers/ata/libata-scsi.c
>> @@ -303,6 +303,172 @@
>>  	return rc;
>>  }
>>
>> +static void ide_fixstring (u8 *s, const int bytecount)
>> +{
>> +	u8 *p = s, *end = &s[bytecount & ~1]; /* bytecount must be even */
>> +
>> +#ifndef __BIG_ENDIAN
>> +# ifdef __LITTLE_ENDIAN
>> +	/* convert from big-endian to host byte order */
>> +	for (p = end ; p != s;) {
>> +		unsigned short *pp = (unsigned short *) (p -= 2);
>> +		*pp = ntohs(*pp);
>> +	}
>> +# else
>> +#  error "Please fix <asm/byteorder.h>"
>> +# endif
>> +#endif
> 
> Ugly. ntohs() will work on BE arches also.
> 
>> +static void ide_fix_driveid (struct hd_driveid *id)
>> +{
>> +#ifndef __LITTLE_ENDIAN
>> +# ifdef __BIG_ENDIAN
> 
> Ditto.

Agreed...

	Jeff