From: Rex Lu Limit tx/rx buffer address to 32-bit address space for board with more than 4GB DRAM. Fixes: 804775dfc2885 ("net: ethernet: mtk_eth_soc: add support for Wireless Ethernet Dispatch (WED)") Fixes: 6757d345dd7db ("net: ethernet: mtk_wed: introduce hw_rro support for MT7988") Tested-by: Daniel Pawlik Tested-by: Matteo Croce Signed-off-by: Rex Lu Co-developed-by: Lorenzo Bianconi Signed-off-by: Lorenzo Bianconi --- Changes in v2: - Add missing Fixes tags - Avoid possible deadlock if dma_set_mask_and_coherent fails - Link to v1: https://lore.kernel.org/r/20251008-wed-4g-ram-limitation-v1-1-16fe55e1d042@kernel.org --- drivers/net/ethernet/mediatek/mtk_wed.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c index 3dbb113b792cf00fb4f89ab20f7e7fa72ecac260..1ed1f88dd7f8bc69bf4cb2803b907c8d7776ae20 100644 --- a/drivers/net/ethernet/mediatek/mtk_wed.c +++ b/drivers/net/ethernet/mediatek/mtk_wed.c @@ -677,7 +677,7 @@ mtk_wed_tx_buffer_alloc(struct mtk_wed_device *dev) void *buf; int s; - page = __dev_alloc_page(GFP_KERNEL); + page = __dev_alloc_page(GFP_KERNEL | GFP_DMA32); if (!page) return -ENOMEM; @@ -800,7 +800,7 @@ mtk_wed_hwrro_buffer_alloc(struct mtk_wed_device *dev) struct page *page; int s; - page = __dev_alloc_page(GFP_KERNEL); + page = __dev_alloc_page(GFP_KERNEL | GFP_DMA32); if (!page) return -ENOMEM; @@ -2426,6 +2426,10 @@ mtk_wed_attach(struct mtk_wed_device *dev) dev->version = hw->version; dev->hw->pcie_base = mtk_wed_get_pcie_base(dev); + ret = dma_set_mask_and_coherent(hw->dev, DMA_BIT_MASK(32)); + if (ret) + goto out; + if (hw->eth->dma_dev == hw->eth->dev && of_dma_is_coherent(hw->eth->dev->of_node)) mtk_eth_set_dma_device(hw->eth, hw->dev); --- base-commit: 07fdad3a93756b872da7b53647715c48d0f4a2d0 change-id: 20250930-wed-4g-ram-limitation-6490e7ed9d39 Best regards, -- Lorenzo Bianconi