Hi Finn,
CC Christoph
On Thu, May 3, 2018 at 10:38 AM, Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx> wrote:
On Thu, 3 May 2018, Geert Uytterhoeven wrote:
--- a/drivers/net/ethernet/apple/macmace.c
+++ b/drivers/net/ethernet/apple/macmace.c
@@ -203,6 +203,10 @@ static int mace_probe(struct platform_device *pdev)
unsigned char checksum = 0;
int err;
+ err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+ if (err)
+ return err;
+
dev = alloc_etherdev(PRIV_BYTES);
if (!dev)
return -ENOMEM;
Shouldn't this be handled in the platform code that instantiates the
device, i.e. in arch/m68k/mac/config.c:mac_platform_init()?
I wondered about that too. The downside is that I'd have to convert
platform_device_register_simple() into platform_device_register() and add
all of the boilerplate that goes with that, for little gain.
Cfr. commit f61e64310b75733d ("m68k: set dma and coherent masks for
platform FEC ethernets").
Yes, I looked at that patch before I sent this one. It makes sense to set
the mask when defining the device since some devices tend to have inherent
limitations (but that's not really applicable here).
Moreover, it turns out that a number of platform drivers already call
dma_set_mask_and_coherent() or dma_coerce_mask_and_coherent() or similar.
I figured that platform drivers aren't expected to be particularly
portable. Well, I'd expect macmace and macsonic to be portable to NuBus
PowerMacs, but AFAIK the correct mask would remain DMA_BIT_MASK(32).
So that's how I ended up with this patch. But if you are not pursuaded by
my reasoning then just say the word and I'll take another approach.
Perhaps you can add a new helper (platform_device_register_simple_dma()?)
that takes the DMA mask, too?
With people setting the mask to kill the WARNING splat, this may become
more common.
struct platform_device_info already has a dma_mask field, but
platform_device_register_resndata() explicitly sets it to zero.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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