Re: [PATCH rdma-next] RDMA/erdma: restrict the driver to little-endian systems
From: Cheng Xu
Date: Thu Aug 06 2026 - 05:03:27 EST
On 8/6/26 4:48 PM, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@xxxxxxxxxx>
>
> The eRDMA device interface requires explicit byte ordering, but several
> DMA-visible values that should be little-endian remain native-endian.
> Command request payloads are copied verbatim, data-path SQE headers are
> written without cpu_to_le64(), and kernel doorbell records are assigned
> plain u64 values. The command completion path also reads a little-endian
> SQE header without conversion.
>
> These paths are byte-swapped on big-endian kernels and can break command
> processing during probe. Since complete big-endian support requires
> converting every device-visible structure, depend on !CPU_BIG_ENDIAN.
>
> Fixes: ca7fd6cff3b8 ("RDMA/erdma: Add driver to kernel build environment")
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
> ---
> RDMA/erdma: restrict the driver to little-endian systems
> ---
> drivers/infiniband/hw/erdma/Kconfig | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
Acked-by: Cheng Xu <chengyou@xxxxxxxxxxxxxxxxx>
> diff --git a/drivers/infiniband/hw/erdma/Kconfig b/drivers/infiniband/hw/erdma/Kconfig
> index 267fc1f3c42a..745e5551773f 100644
> --- a/drivers/infiniband/hw/erdma/Kconfig
> +++ b/drivers/infiniband/hw/erdma/Kconfig
> @@ -1,7 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0-only
> config INFINIBAND_ERDMA
> tristate "Alibaba Elastic RDMA Adapter (ERDMA) support"
> - depends on PCI_MSI && 64BIT
> + depends on PCI_MSI && 64BIT && !CPU_BIG_ENDIAN
> depends on INFINIBAND_ADDR_TRANS
> depends on INFINIBAND_USER_ACCESS
> help
>
> ---
> base-commit: 961ac0f0c5e414abdd6b33fae84b311d9fde0bd0
> change-id: 20260806-missing-endianness-conversion-for-64-f0af69246071
>
> Best regards,
> --
> Leon Romanovsky <leonro@xxxxxxxxxx>