> -----Original Message-----
> From: Arnd Bergmann [mailto:a...@arndb.de]
> Sent: Monday, July 10, 2017 6:14 PM
> Subject: [PATCH] dpaa_eth: use correct device for DMA mapping API
>
> Geert Uytterhoeven ran into a build error without CONFIG_HAS_DMA,
> as a result of the driver calling set_dma_ops(). While we can
> fix the build error in the dma-mapping implementation, there is
> another problem in this driver:
>
> The configuration for the DMA is done by the platform code,
> looking up information about the system from the device tree.
> This copies the information only in an incomplete way, setting
> the dma_map_ops and forcing a specific mask, but ignoring all
> settings regarding IOMMU, coherence etc.
>
> A better way to avoid the problem is to only ever pass a device
> into the dma_mapping implementation that has been setup by the
> platform code. In this case, that is the parent device, so we
> can get that pointer at probe time. Fortunately, we already have
> a pointer in the device specific structure for that, so we only
> need to modify that.
>
> Fixes: fb52728a9294 ("dpaa_eth: reuse the dma_ops provided by the FMan MAC
> device")
> Signed-off-by: Arnd Bergmann <a...@arndb.de>
> ---
> Not tested, please see if this works before applying!
> ---
> drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> index 757b873735a5..f7b0b928cd53 100644
> --- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> +++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
> @@ -2646,14 +2646,6 @@ static int dpaa_eth_probe(struct platform_device
> *pdev)
> priv->buf_layout[RX].priv_data_size = DPAA_RX_PRIV_DATA_SIZE; /* Rx
> */
> priv->buf_layout[TX].priv_data_size = DPAA_TX_PRIV_DATA_SIZE; /* Tx
> */
>
> - /* device used for DMA mapping */
> - set_dma_ops(dev, get_dma_ops(&pdev->dev));
> - err = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(40));
> - if (err) {
> - dev_err(dev, "dma_coerce_mask_and_coherent() failed\n");
> - goto dev_mask_failed;
> - }
> -
> /* bp init */
> for (i = 0; i < DPAA_BPS_NUM; i++) {
> int err;
> @@ -2665,7 +2657,8 @@ 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);
> - dpaa_bps[i]->dev = dev;
> + /* 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) {
> --
> 2.9.0
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
You also missed this related change:
@@ -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.
Regards,
Madalin
