Hi Christoph,
On 28/01/2025 07:47, Christoph Hellwig wrote:
On Tue, Jan 28, 2025 at 07:43:23AM +0100, Jean-Michel Hautbois wrote:
It really should not be hard. The dynamic mappings already work fine
as m68k is using the generic code. So the only thing you want is
to dip into the glonal pool for coherent allocations. For that you
need to select the DMA_GLOBAL_POOL config option and fill the pool
with dma_init_global_coherent().
Isn't it done in patch 1/2 ? Or did I miss something ?
The point is that this is all you need. No need for new dma ops.
Indeed, I tested it and it works fine.
I have removed the test in fec_main to be certain, but I think it would
be better to change the COLDFIRE_COHERENT_DMA conditional ?
What sounds like the most efficient way ?
I can' do:
- #if defined(CONFIG_COLDFIRE) && !defined(CONFIG_COLDFIRE_COHERENT_DMA)
+ #if defined(CONFIG_COLDFIRE) && !defined(CONFIG_COLDFIRE_COHERENT_DMA)
&& !defined(CONFIG_DMA_GLOBAL_POOL)
I suppose it would be better to modify it in the Kconfig, but I can't
find a nice way to do it without having a circular dependency:
arch/m68k/Kconfig.cpu
@@ -555,6 +555,7 @@ config COLDFIRE_COHERENT_DMA
default y
depends on COLDFIRE
depends on !HAVE_CACHE_CB && !CACHE_D && !CACHE_BOTH
+ depends on DMA_GLOBAL_POOL
=>
error: recursive dependency detected!
symbol DMA_DIRECT_REMAP is selected by M68K_NONCOHERENT_DMA
symbol M68K_NONCOHERENT_DMA depends on COLDFIRE_COHERENT_DMA
symbol COLDFIRE_COHERENT_DMA depends on DMA_GLOBAL_POOL
symbol DMA_GLOBAL_POOL depends on DMA_DIRECT_REMAP
I will send a v2 with the global pool.
Thanks !
JM
