Re: [PATCH libata-dev#upstream-fixes] libata: fix drive side 80c cable check, take 3

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Hello, I wrote:

>> The 80c wire bit is bit 13, not 14.  Bit 14 is always 1 if word93 is
>> implemented.  This increases the chance of incorrect wire detection
>> especially because host side cable detection is often unreliable and
>> we sometimes soley depend on drive side cable detection.  Fix the test
>> and add word93 validity check.

>> Signed-off-by: Tejun Heo <htejun@gmail.com>

>> diff --git a/include/linux/ata.h b/include/linux/ata.h
>> index 1df9416..939be94 100644
>> --- a/include/linux/ata.h
>> +++ b/include/linux/ata.h
>> @@ -347,7 +347,7 @@ static inline int ata_drive_40wire(const u16 *dev_id)
>>  {
>>      if (ata_id_major_version(dev_id) >= 5 && ata_id_is_sata(dev_id))
>>          return 0;    /* SATA */
>> -    if (dev_id[93] & 0x4000)
>> +    if ((dev_id[93] & 0xE000) == 0x6000)
>>          return 0;    /* 80 wire */
>>      return 1;
>>  }

>    Wrong, wrong as well! The correct value to compare with would be 0x4000.

    Sorry for the false alarm -- those opposite senses on CBLID- have really 
confused me. :-<

MBR, Sergei