Re: [PATCH 08/28] MIPS: make dma_sync_*_for_cpu a little less overzealous

From
Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Date
2020-09-01 14:01:52
Also in
alsa-devel, linux-doc, linux-iommu, linux-media, linux-mips, linux-mm, linux-nvme, linux-samsung-soc, linux-scsi, lkml, netdev, nouveau
Reply to
Christoph Hellwig, 2020-08-19
On Wed, Aug 19, 2020 at 08:55:35AM +0200, Christoph Hellwig wrote:
When transferring DMA ownership back to the CPU there should never
be any writeback from the cache, as the buffer was owned by the
device until now.  Instead it should just be invalidated for the
mapping directions where the device could have written data.
Note that the changes rely on the fact that kmap_atomic is stubbed
out for the !HIGHMEM case to simplify the code a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/mips/mm/dma-noncoherent.c | 44 +++++++++++++++++++++-------------
 1 file changed, 28 insertions(+), 16 deletions(-)
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Thread (77 messages) 77 messages, 8 authors, last reply 2020-09-03
Keyboard shortcuts
hback out one level
jnext message in thread / next series-diff position
kprevious message in thread / previous series-diff position
ldrill in
Escclose help / fold thread tree
?toggle this help