On 12/25/19 11:36 AM, Pali Rohár wrote: > On Wednesday 25 December 2019 11:26:47 Jens Axboe wrote: >> On 12/25/19 11:18 AM, Pali Rohár wrote: >>> Hello Sascha! >>> >>> On Friday 13 December 2019 09:04:08 Sascha Hauer wrote: >>>> ata_qc_complete_multiple() is called with a mask of the still active >>>> tags. >>>> >>>> mv_sata doesn't have this information directly and instead calculates >>>> the still active tags from the started tags (ap->qc_active) and the >>>> finished tags as (ap->qc_active ^ done_mask) >>>> >>>> Since 28361c40368 the hw_tag and tag are no longer the same and the >>>> equation is no longer valid. In ata_exec_internal_sg() ap->qc_active is >>>> initialized as 1ULL << ATA_TAG_INTERNAL, but in hardware tag 0 is >>>> started and this will be in done_mask on completion. ap->qc_active ^ >>>> done_mask becomes 0x100000000 ^ 0x1 = 0x100000001 and thus tag 0 used as >>>> the internal tag will never be reported as completed. >>>> >>>> This is fixed by introducing ata_qc_get_active() which returns the >>>> active hardware tags and calling it where appropriate. >>>> >>>> This is tested on mv_sata, but sata_fsl and sata_nv suffer from the same >>>> problem. There is another case in sata_nv that most likely needs fixing >>>> as well, but this looks a little different, so I wasn't confident enough >>>> to change that. >>> >>> I can confirm that sata_nv.ko does not work in 4.18 (and new) kernel >>> version correctly. More details are in email: >>> >>> https://lore.kernel.org/linux-ide/20191225180824.bql2o5whougii4ch@pali/T/ >>> >>> I tried this patch and it fixed above problems with sata_nv.ko. It just >>> needs small modification (see below). >>> >>> So you can add my: >>> >>> Tested-by: Pali Rohár <pali.rohar@xxxxxxxxx> >>> >>> And I hope that patch would be backported to 4.18 and 4.19 stable >>> branches soon as distributions kernels are broken for machines with >>> these nvidia sata controllers. >>> >>> Anyway, what is that another case in sata_nv which needs to be fixed >>> too? >> >> Thanks for testing, I've applied this for 5.5 and marked it for stable. > > It is this one? > https://git.kernel.dk/cgit/linux-block/commit/?h=libata-5.5&id=d80f359d0ebddb3ab3e9cc3fe96f244827ae7b09 > > Because there is missing EXPORT_SYMBOL_GPL for ata_qc_get_active() > function as I wrote in previous email. I missed that, I'll add it. Thanks! -- Jens Axboe
