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.
Modified files:
Index: src/sys/dev/pci/ixgbe/ix_txrx.c
diff -u src/sys/dev/pci/ixgbe/ix_txrx.c:1.75 src/sys/dev/pci/ixgbe/ix_txrx.c:1.76
--- src/sys/dev/pci/ixgbe/ix_txrx.c:1.75 Tue May 18 05:29:15 2021
+++ src/sys/dev/pci/ixgbe/ix_txrx.c Thu May 20 01:02:42 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: ix_txrx.c,v 1.75 2021/05/18 05:29:15 msaitoh Exp $ */
+/* $NetBSD: ix_txrx.c,v 1.76 2021/05/20 01:02:42 ryo Exp $ */
/******************************************************************************
@@ -64,7 +64,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ix_txrx.c,v 1.75 2021/05/18 05:29:15 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ix_txrx.c,v 1.76 2021/05/20 01:02:42 ryo Exp $");
#include "opt_inet.h"
#include "opt_inet6.h"
@@ -2208,7 +2208,7 @@ ixgbe_dma_malloc(struct adapter *adapter
}
r = bus_dmamem_map(dma->dma_tag->dt_dmat, &dma->dma_seg, rsegs,
- size, &dma->dma_vaddr, BUS_DMA_NOWAIT);
+ size, &dma->dma_vaddr, BUS_DMA_NOWAIT | BUS_DMA_COHERENT);
if (r != 0) {
aprint_error_dev(dev, "%s: bus_dmamem_map failed; error %d\n",
__func__, r);
