Hi,

On 25/07/16 20:54, Maxime Ripard wrote:

On Wed, Jul 20, 2016 at 10:03:16AM +0200, LABBE Corentin wrote:

quoted

This patch add support for sun8i-emac ethernet MAC hardware.
It could be found in Allwinner H3/A83T/A64 SoCs.

It supports 10/100/1000 Mbit/s speed with half/full duplex.
It can use an internal PHY (MII 10/100) or an external PHY
via RGMII/RMII.

Signed-off-by: LABBE Corentin <redacted>
---
 drivers/net/ethernet/allwinner/Kconfig      |   13 +
 drivers/net/ethernet/allwinner/Makefile     |    1 +
 drivers/net/ethernet/allwinner/sun8i-emac.c | 2129 +++++++++++++++++++++++++++
 3 files changed, 2143 insertions(+)
 create mode 100644 drivers/net/ethernet/allwinner/sun8i-emac.c

...

quoted

diff --git a/drivers/net/ethernet/allwinner/sun8i-emac.c b/drivers/net/ethernet/allwinner/sun8i-emac.c
new file mode 100644
index 0000000..fc0c1dd
--- /dev/null
+++ b/drivers/net/ethernet/allwinner/sun8i-emac.c

...

quoted

+
+/* struct dma_desc - Structure of DMA descriptor used by the hardware
+ * @status: Status of the frame written by HW, so RO for the
+ *	driver (except for BIT(31) which is R/W)
+ * @ctl: Information on the frame written by the driver (INT, len,...)
+ * @buf_addr: physical address of the frame data
+ * @next: physical address of next dma_desc
+ */
+struct dma_desc {
+	u32 status;
+	u32 ctl;
+	u32 buf_addr;
+	u32 next;
+};

You should use the endian-aware variants here.

For the records: just doing the sparse annotation with __le32 here will
of course not be sufficient to make it work on BE kernels. I added
proper endianness conversion to all accesses to the descriptors and got
it to work with an arm64 big-endian kernel on the Pine64.

I put a patch here:
https://gist.github.com/apritzel/bc792c4dbbd8789f5f18aef538e8c440

This particular version is untested (though it compiles), since I just
adapted the working patch against the newer driver code and couldn't
test it yet.
I am not really an endianness expert, so don't know if there are smarter
ways to tackle this, if we should for instance provide access wrappers
to the DMA descriptor fields.

I will try to test this later today, if that works, feel free to merge
those changes into your driver.

Cheers,
Andre.