[PATCH v4 0/9] Add Aspeed AST2700 SDRAM EDAC support

[Ryan Chen <ryan_chen@aspeedtech.com>]

Add ECC error reporting for the Aspeed AST2700 SoC to the existing
aspeed_edac driver.

The AST2700 memory controller keeps the same overall EDAC programming
model as the earlier Aspeed BMC SoCs, but uses a different register
layout, a split interrupt status/clear/mask scheme and DDR4/DDR5 memory.
Rather than fork the driver, the existing code is first tidied and
generalised, then the AST2700 is added as one more per-SoC variant.

Patches 1-4 are bug fixes and cleanups to the existing driver. Patch 5
documents the AST2700 binding, patches 6 and 7 rework the implementation
to accommodate it, and patch 8 adds the AST2700 support itself. Patch 9 is
Stefan's step-down patch, amended to leave the entry in place with me
as its reviewer.

Signed-off-by: Ryan Chen <ryan_chen@aspeedtech.com>
---
Changes in v4:
- Put the bug fixes first: the two fixes are now patches 1 and 2, the
  cleanups 3 and 4, and the bindings patch moves to 5 ahead of the
  AST2700 work.
- Explain in patch 1 where the grain value comes from, rather than the
  warning it silences.
- Drop the Cc: stable tags from the two fixes. Neither meets the bar in
  Documentation/process/stable-kernel-rules.rst; the Fixes: tags stay.
- Merge Stefan's step-down patch into patch 9, keeping the MAINTAINERS
  entry alive with a reviewer instead of removing it.
- Link to v3: https://lore.kernel.org/r/20260916-edac-v3-0-23e9ed2fbdf9@aspeedtech.com

Changes in v3:
- Establish the AST2700 interrupt mask in the driver rather than
  deriving it from the register's contents: ast2700_set_irq() now
  writes the mask outright, masking every source and unmasking only
  the ECC ones, and the mask is established before the interrupt is
  requested.
- New patch: add myself as a reviewer for the driver in MAINTAINERS.
- Tested on an AST2600 with CONFIG_PROVE_LOCKING=y; injected correctable
  errors are reported from the interrupt handler with no lockdep reports.
- Link to v2: https://lore.kernel.org/r/20260824-edac-v2-0-c8d8bb693586@aspeedtech.com

Changes in v2:
- New patch: free the ECC interrupt before the mem_ctl_info in
  aspeed_remove(). The interrupt is requested with devm_request_irq() and
  is only released after .remove() has returned, so edac_mc_free() could
  free the handler's context while the handler was still running on
  another CPU.
- Acquire the register lock with the irqsave variant in init_csrows() and
  in aspeed_probe(). The interrupt handler takes the same lock in hardirq
  context.
- Move the dev_dbg() of the interrupt status register out of the
  raw_spinlock critical section in the interrupt handler.
- Opt aspeed_edac.o into context analysis in drivers/edac/Makefile. The
  check is opt-in per object, so without it the __guarded_by() annotation
  added by the same patch was never actually verified.
- Return IRQ_NONE from ast2700_dramc_isr() when no ECC interrupt status
  bit is set; the handler clears only the ECC bits, so unconditionally
  claiming the interrupt could livelock the level-triggered line.
- Tested v2 on both AST2600 and AST2700 by injecting a correctable
  error with the memory controller's ECC error injection; each is
  reported as a CE with the expected failure address.
- Link to v1: https://lore.kernel.org/r/20260812-edac-v1-0-03992edea297@aspeedtech.com

---
Ryan Chen (8):
      EDAC/aspeed: Set the DIMM grain
      EDAC/aspeed: Free the interrupt before the mem_ctl_info on remove
      EDAC/aspeed: Clean up whitespace and include ordering
      EDAC/aspeed: Free the mem_ctl_info unconditionally on remove
      dt-bindings: edac: aspeed: Add AST2700 SDRAM EDAC
      EDAC/aspeed: Replace regmap with direct register access
      EDAC/aspeed: Abstract SoC differences behind chip data
      EDAC/aspeed: Add AST2700 support

Stefan M Schaeckeler (1):
      MAINTAINERS: Step down as Aspeed AST2500 EDAC driver maintainer

 CREDITS                                            |   8 +
 .../bindings/edac/aspeed,ast2400-sdram-edac.yaml   |   6 +-
 MAINTAINERS                                        |   2 +-
 drivers/edac/Makefile                              |   1 +
 drivers/edac/aspeed_edac.c                         | 426 ++++++++++++++-------
 5 files changed, 293 insertions(+), 150 deletions(-)
---
base-commit: 5464985e42c04e335fb30e38fbc409c997db9bec
change-id: 20260625-edac-8e960e02e7f7

Best regards,
-- 
Ryan Chen <ryan_chen@aspeedtech.com>