Module Name: src
Committed By: ryo
Date: Thu May 20 01:02:42 UTC 2021
Modified Files:
src/sys/dev/pci/ixgbe: ix_txrx.c
Log Message:
Added BUS_DMA_COHERENT flag to bus_dmamem_map() to improve stability on aarch64.
In ixgbe, TX/RX descriptor rings are configured in 16-byte units.
If BUS_DMA_COHERENT is not specified, cpu cache (writeback/invalidate)
operations by bus_dmamap_sync() in aarch64 (arm/arm32/bus_dma.c) are done per
cache line size (usually 64 bytes). As a result, adjacent descriptors conflict
with the DMA operation, resulting in unstable operation.
To avoid this, descriptors area should be mapped as non-cache with
BUS_DMA_COHERENT.
thanks to msaitoh@ for his help in debugging.
To generate a diff of this commit:
cvs rdiff -u -r1.75 -r1.76 src/sys/dev/pci/ixgbe/ix_txrx.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
