[PATCH v3 0/3] dmaengine: xilinx_dma: Fixes and optimizations for AXIDMA and MCDMA channel management

[Suraj Gupta <suraj.gupta2@amd.com>]

This patch series addresses issues and optimizations in the Xilinx
AXI DMA and MCDMA drivers:
1. Fix channel idle state management in the interrupt handlers.
2. Enable transfer chaining by removing unnecessary idle restrictions.
3. Optimize control register writes and channel start logic.

Note: The patches in this series were part of following IRQ coalescing
series which is under discussion:
https://lore.kernel.org/all/20250710101229.804183-1-suraj.gupta2@amd.com/

Changes in V3:
- Patch 2: Restrict the idle-check removal to scatter-gather mode. Direct
  (non-SG) mode has no descriptor queue, so writing the BTT register while
  a transfer is in flight would corrupt the active transfer; keep those
  transfers serialized by retaining the idle check on the non-SG path.
  MCDMA always operates in scatter-gather mode and is unaffected. Update
  the commit description accordingly.

Changes in V2:
- Apply similar fixes and optimizations to MCDMA as well.
- Expand the 1/3 commit description with when the described issue occurs.

Suraj Gupta (3):
  dmaengine: xilinx_dma: Fix channel idle state management in AXIDMA and
    MCDMA interrupt handlers
  dmaengine: xilinx_dma: Enable transfer chaining for AXIDMA and MCDMA
    by removing idle restriction
  dmaengine: xilinx_dma: Optimize control register write and channel
    start logic for AXIDMA and MCDMA in corresponding start_transfer()

 drivers/dma/xilinx/xilinx_dma.c | 38 +++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 14 deletions(-)

-- 
2.25.1