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 equation is no longer valid.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. -- Pali Rohár pali.rohar@xxxxxxxxx
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