| Message ID | 20250210-locked-dart-v1-0-5d97fe247f35@rosenzweig.io (mailing list archive) |
|---|---|
| Headers | show |
| Series | iommu: apple-dart: Support locked DARTs | expand |
On Mon, Feb 10, 2025 at 2:44 PM Alyssa Rosenzweig <alyssa@rosenzweig.io> wrote: > > Some DARTs on Apple SoCs are "locked" at boot time, meaning we cannot > write most of their configuration registers. Currently, we refuse to > probe locked DARTs and do not include any in the upstream device trees. > However, the DARTs used for the display controller are locked, so we > need to handle locked DARTs as a prerequisite for a KMS driver. > > This series teaches the iommu/apple-dart driver about locked DARTs, > preparing for a future upstream display driver. It has been extensively > tested downstream with our work-in-progress display driver. > > Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io> > --- > Alyssa Rosenzweig (5): > iommu/dart: Track if the DART is locked > iommu/dart: Skip reset for locked DARTs > iommu/dart: Set DMA domain for locked DARTs > iommu/dart: Reject identity domain for locked DARTs > iommu/dart: Assert !locked when configuring > > drivers/iommu/apple-dart.c | 47 +++++++++++++++++++++++++++++++--------------- > 1 file changed, 32 insertions(+), 15 deletions(-) > --- > base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b > change-id: 20250210-locked-dart-d7ece05f19a8 > > Best regards, > -- > Alyssa Rosenzweig <alyssa@rosenzweig.io> > > Series LGTM, having looked over this many times as part of kernel maintenance for Fedora Asahi Remix. Reviewed-by: Neal Gompa <neal@gompa.dev>
Some DARTs on Apple SoCs are "locked" at boot time, meaning we cannot write most of their configuration registers. Currently, we refuse to probe locked DARTs and do not include any in the upstream device trees. However, the DARTs used for the display controller are locked, so we need to handle locked DARTs as a prerequisite for a KMS driver. This series teaches the iommu/apple-dart driver about locked DARTs, preparing for a future upstream display driver. It has been extensively tested downstream with our work-in-progress display driver. Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io> --- Alyssa Rosenzweig (5): iommu/dart: Track if the DART is locked iommu/dart: Skip reset for locked DARTs iommu/dart: Set DMA domain for locked DARTs iommu/dart: Reject identity domain for locked DARTs iommu/dart: Assert !locked when configuring drivers/iommu/apple-dart.c | 47 +++++++++++++++++++++++++++++++--------------- 1 file changed, 32 insertions(+), 15 deletions(-) --- base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b change-id: 20250210-locked-dart-d7ece05f19a8 Best regards,