Hi Greg,
On Mon, Mar 26, 2018 at 3:36 PM, Greg Ungerer <g...@linux-m68k.org> wrote:
> As of commit 205e1b7f51e4 ("dma-mapping: warn when there is no
> coherent_dma_mask") the Freescale FEC driver is issuing the following
> warning on driver initialization on ColdFire systems:
>
> WARNING: CPU: 0 PID: 1 at ./include/linux/dma-mapping.h:516 0x40159e20
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper Not tainted 4.16.0-rc7-dirty #4
> Stack from 41833dd8:
> 41833dd8 40259c53 40025534 40279e26 00000003 00000000 4004e514
> 41827000
> 400255de 40244e42 00000204 40159e20 00000009 00000000 00000000
> 4024531d
> 40159e20 40244e42 00000204 00000000 00000000 00000000 00000007
> 00000000
> 00000000 40279e26 4028d040 40226576 4003ae88 40279e26 418273f6
> 41833ef8
> 7fffffff 418273f2 41867028 4003c9a2 4180ac6c 00000004 41833f8c
> 4013e71c
> 40279e1c 40279e26 40226c16 4013ced2 40279e26 40279e58 4028d040
> 00000000
> Call Trace:
> [<40025534>] 0x40025534
> [<4004e514>] 0x4004e514
> [<400255de>] 0x400255de
> [<40159e20>] 0x40159e20
> [<40159e20>] 0x40159e20
>
> It is not fatal, the driver and the system continue to function normally.
>
> As per the warning the coherent_dma_mask is not set on this device.
> There is nothing special about the DMA memory coherency on this hardware
> so we can just set the mask to 32bits during probe.
>
> Signed-off-by: Greg Ungerer <g...@linux-m68k.org>
Thanks for your patch!
> ---
> drivers/net/ethernet/freescale/fec_main.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> Is this the best way to handle this problem?
> Comments welcome...
>
> diff --git a/drivers/net/ethernet/freescale/fec_main.c
> b/drivers/net/ethernet/freescale/fec_main.c
> index d4604bc..3cb130a 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -2702,6 +2702,8 @@ static int fec_enet_alloc_queue(struct net_device *ndev)
> int ret = 0;
> struct fec_enet_priv_tx_q *txq;
>
> + dma_set_coherent_mask(&fep->pdev->dev, DMA_BIT_MASK(32));
> +
> for (i = 0; i < fep->num_tx_queues; i++) {
> txq = kzalloc(sizeof(*txq), GFP_KERNEL);
> if (!txq) {
As per your other email, this does not trigger on iMX systems using DT.
Hence I'm wondering if the Coldfire platform code shouldn't just do the
same what drivers/of/device.c does, cfr.
https://www.spinics.net/lists/linux-m68k/msg10929.html?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
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
