lkml.org 
[lkml]   [2023]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH v6 1/6] riscv: mm: dma-noncoherent: Switch using function pointers for cache management
On Tue, Jan 10, 2023 at 04:03:06PM +0100, Arnd Bergmann wrote:
> On Tue, Jan 10, 2023, at 08:01, Christoph Hellwig wrote:
> > On Mon, Jan 09, 2023 at 01:59:12PM +0100, Arnd Bergmann wrote:
> >> I had another look at the arm64 side, which (like the zicbom
> >> variant) uses 'clean' on dma_sync_single_for_device(DMA_FROM_DEVICE),
> >> as that has changed not that long ago, see
> >>
> >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c50f11c6196f45c92ca48b16a5071615d4ae0572
> >
> > which IIRC has been reverted recently.
>
> To clarify: I was looking at arch_sync_dma_for_device(), which
> changed from 'invalidate' to 'clean' last June in commit
> c50f11c6196f ("arm64: mm: Don't invalidate FROM_DEVICE buffers
> at start of DMA transfer"). I don't see a revert for that.
>
> The one that was reverted recently is arch_dma_prep_coherent, which
> was changed and reverted in
>
> c44094eee32 Aug 23 2022 flush->clean
> b7d9aae4048 Dec 6 2022 clean->flush
>
> I'm primarily interested in the streaming mappings (arch_sync_*)
> at the moment.

Just as an FYI, but we plan to revert the revert (i.e. go back to 'clean')
here once Qualcomm's modem firmware loader has been updated:

https://lore.kernel.org/r/20230109034843.23759-1-quic_sibis@quicinc.com

Will

\
 
 \ /
  Last update: 2023-03-26 23:35    [W:0.103 / U:5.392 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site