[TLDR: I'm adding this report to the list of tracked Linux kernel regressions; the text you find below is based on a few templates paragraphs you might have encountered already in similar form. See link in footer if these mails annoy you.]
On 22.09.23 15:40, Hector Martin wrote:
Commit a4fdd9762272 ("iommu: Use flush queue capability") hid the IOMMU_DOMAIN_DMA_FQ domain type from domain allocation. A check was introduced in iommu_dma_init_domain() to fall back if not supported, but this check runs too late: by that point, devices have been attached to the IOMMU, and the IOMMU driver might not expect FQ domains at ops->attach_dev() time.
Ensure that we immediately clamp FQ domains to plain DMA if not supported by the driver at device attach time, not later.
This regressed apple-dart in v6.5. [...]
Thanks for the report. To be sure the issue doesn't fall through the cracks unnoticed, I'm adding it to regzbot, the Linux kernel regression tracking bot:
#regzbot ^introduced a4fdd9762272 #regzbot title iommu: apple-dart regressed #regzbot monitor: https://lore.kernel.org/all/20230922-iommu-type-regression-v2-1-689b2ba9b673... #regzbot fix: iommu/apple-dart: Handle DMA_FQ domains in attach_dev() #regzbot ignore-activity
This isn't a regression? This issue or a fix for it are already discussed somewhere else? It was fixed already? You want to clarify when the regression started to happen? Or point out I got the title or something else totally wrong? Then just reply and tell me -- ideally while also telling regzbot about it, as explained by the page listed in the footer of this mail.
Developers: When fixing the issue, remember to add 'Link:' tags pointing to the report (the parent of this mail). See page linked in footer for details.
Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr That page also explains what to do if mails like this annoy you.