[PATCH V3 0/3] memory: tegra: Restore MC state on system resume

Ashish Mhetre
2026-04-30T09:52:32Z

The tegra-mc platform driver does not register any dev_pm_ops, so the
SoC-specific ->resume() is never invoked (e.g. tegra186_mc_resume) on
system wake. On Tegra186 and later this means MC client Stream-ID
override registers are not reprogrammed, and clients behind the ARM
SMMU fault on the first DMA after resume.

Patch 1 makes the SoC-level ->resume() callback return void, since the
sole implementation never fails. This simplifies the wrapper added in
the next patch.

Patch 2 registers a dev_pm_ops on the tegra-mc driver and routes the
system resume callback into mc->soc->ops->resume() so the existing SID
restore path runs again on wake.

Patch 3 factors the existing intmask programming out of
tegra_mc_probe() into a helper and reuses it from the resume path so
the MC interrupt mask state, which is also lost across SC7, is
restored on wake too.

Changes in V3:
- New patch 1 to change the SoC ->resume() callback return type from
int to void, so the wrapper in patch 2 does not need to deal with
an err value that is always 0. (Jon Hunter)
- Patches 2 and 3 simplified accordingly, no other functional change.

Changes in V2:
- Split the original single patch into two - register the PM ops and
reprogram the MC interrupt masks on resume.

Ashish Mhetre (3):
memory: tegra: Make ->resume() callback return void
memory: tegra: Wire up system sleep PM ops
memory: tegra: Restore MC interrupt masks on resume

drivers/memory/tegra/mc.c | 37 ++++++++++++++++++++++++++-------
drivers/memory/tegra/tegra186.c | 4 +---
include/soc/tegra/mc.h | 2 +-
3 files changed, 32 insertions(+), 11 deletions(-)

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2.50.1