On 9/20/18 9:07 AM, Sergei Shtylyov wrote:
> On 09/20/2018 05:22 PM, Jens Axboe wrote:
>
>> When we're comparing the hardware completion mask passed in from the
>> driver with the internal tag pending mask, we need to account for the
>> fact that the internal tag is different from the hardware tag. If not,
>> then we can end up either prematurely completing the internal tag (since
>> it's not set in the hw mask), or simply flag an error:
>>
>> ata2: illegal qc_active transition (100000000->00000001)
>>
>> If the internal tag is set, then swap that with the hardware tag in this
>> case before comparing with what the hardware reports.
>>
>> Fixes: 28361c403683 ("libata: add extra internal command")
>> Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=201151
>> Cc: stable@xxxxxxxxxxxxxxx
>> Reported-by: Paul Sbarra <sbarra.paul@xxxxxxxxx>
>> Tested-by: Paul Sbarra <sbarra.paul@xxxxxxxxx>
>> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
>>
>> ---
>>
>> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
>> index 599e01bcdef2..a9dd4ea7467d 100644
>> --- a/drivers/ata/libata-core.c
>> +++ b/drivers/ata/libata-core.c
>> @@ -5359,10 +5359,20 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
>> */
>> int ata_qc_complete_multiple(struct ata_port *ap, u64 qc_active)
>> {
>> + u64 done_mask, ap_qc_active = ap->qc_active;
>> int nr_done = 0;
>> - u64 done_mask;
>>
>> - done_mask = ap->qc_active ^ qc_active;
>> + /*
>> + * If the internal tag is set on ap->qc_active, then we care about
>> + * bit0 on the passed in qc_active mask. Move that bit up to match
>> + * the internal tag.
>> + */
>> + if (ap_qc_active & (1ULL << ATA_TAG_INTERNAL)) {
>
> Maybe BIT_ULL(ATA_TAG_INTERNAL)?
Honestly, I had defines like that, since they hide what's going on, whereas
the above is immediately readable to anyone. If it isn't, they probably
shouldn't be fiddling with that code :-)
Besides, we don't use that anywhere in libata currently. If someone has
a good case for why that should change, I'm all ears. But should be
a separate change.
--
Jens Axboe
