Re: [PATCH] dpaa_eth: use correct device for DMA mapping API

[Arnd Bergmann]

On Tue, Jul 11, 2017 at 10:50 AM, Madalin-cristian Bucur
<madalin.bucur@xxxxxxx> wrote:

> Hi Arnd,
>
> Thanks for looking into this, I've tested your fix, it seems to need more work:
>
> [    0.894968]  platform: DMA map failed
> [    0.898627]  platform: DMA map failed
> [    0.902288]  platform: DMA map failed
> [    0.905947]  platform: DMA map failed
> [    0.909606]  platform: DMA map failed
> [    0.913265]  platform: DMA map failed

I see: the assignment ended up after the first use, so ->dev was still
NULL here.

This should fix the problem you saw here:

diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
index f7b0b928cd53..988c0212ce7e 100644
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
+++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
@@ -2650,6 +2650,8 @@ static int dpaa_eth_probe(struct platform_device *pdev)
  for (i = 0; i < DPAA_BPS_NUM; i++) {
  int err;

+ /* DMA operations are done on the platform-provided device */
+ dpaa_bps[i]->dev = dev->parent;
  dpaa_bps[i] = dpaa_bp_alloc(dev);
  if (IS_ERR(dpaa_bps[i]))
  return PTR_ERR(dpaa_bps[i]);
@@ -2657,8 +2659,6 @@ static int dpaa_eth_probe(struct platform_device *pdev)
  dpaa_bps[i]->raw_size = bpool_buffer_raw_size(i, DPAA_BPS_NUM);
  /* avoid runtime computations by keeping the usable size here */
  dpaa_bps[i]->size = dpaa_bp_size(dpaa_bps[i]->raw_size);
- /* DMA operations are done on the platform-provided device */
- dpaa_bps[i]->dev = dev->parent;

  err = dpaa_bp_alloc_pool(dpaa_bps[i]);
  if (err < 0) {

> @@ -2806,7 +2799,6 @@ static int dpaa_eth_probe(struct platform_device *pdev)
>                 dpaa_bps_free(priv);
>  bp_create_failed:
>  fq_probe_failed:
> -dev_mask_failed:
>  mac_probe_failed:
>                 dev_set_drvdata(dev, NULL);
>                 free_netdev(net_dev);
>
> I'll try to address your concern about performing the DMA mapping on a different
> device than the one set up by the platform code.

Thanks!

     Arnd