From 35d01728c65d765dec0bdfc48eeaf255abf44371 Mon Sep 17 00:00:00 2001 From: Rafal Jaworowski Date: Wed, 19 Aug 2009 14:39:08 +0000 Subject: [PATCH] Fix USB cache sync operations for platforms with non-coherent DMA. - usb_pc_cpu_invalidate() is called between [consecutive] reads from a device, so a sequence of BUS_DMASYNC_POSTREAD and _PREREAD should be used. Note we cannot use or'ed shorthand ( _POSTREAD | _PREREAD) for BUS_DMASYNC flags, as the low level bus dma sync operation is implementation dependent and we cannot assume the required order of operations to be guaranteed. - usb_pc_cpu_flush() is called before writing to a device, so BUS_DMASYNC_PREWRITE should be used. Submitted by: Grzegorz Bernacki Reviewed by: HPS, arm@, usb@ ML Tested by: HPS, Mike Tancsa Approved by: re (kib) Obtained from: Semihalf --- sys/dev/usb/usb_busdma.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/sys/dev/usb/usb_busdma.c b/sys/dev/usb/usb_busdma.c index e5d6ed7951e..3769102c510 100644 --- a/sys/dev/usb/usb_busdma.c +++ b/sys/dev/usb/usb_busdma.c @@ -679,8 +679,8 @@ usb_pc_cpu_invalidate(struct usb_page_cache *pc) /* nothing has been loaded into this page cache! */ return; } - bus_dmamap_sync(pc->tag, pc->map, - BUS_DMASYNC_POSTWRITE | BUS_DMASYNC_POSTREAD); + bus_dmamap_sync(pc->tag, pc->map, BUS_DMASYNC_POSTREAD); + bus_dmamap_sync(pc->tag, pc->map, BUS_DMASYNC_PREREAD); } /*------------------------------------------------------------------------* @@ -693,8 +693,7 @@ usb_pc_cpu_flush(struct usb_page_cache *pc) /* nothing has been loaded into this page cache! */ return; } - bus_dmamap_sync(pc->tag, pc->map, - BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD); + bus_dmamap_sync(pc->tag, pc->map, BUS_DMASYNC_PREWRITE); } /*------------------------------------------------------------------------*