From dac35cd606d091120acba9213c70a9dd85fd9f5e Mon Sep 17 00:00:00 2001 From: Xu Rao Date: Thu, 11 Jun 2026 14:45:30 +0800 Subject: thunderbolt: stream: Unmap buffers with mapped size The size passed to dma_unmap_page() must match the size used for the corresponding dma_map_page() call. Stream RX and TX buffers are mapped with TB_MAX_FRAME_SIZE when the buffer pools are allocated. However, tbstream_ring_free() currently uses tb_ring_frame_size() as the unmap size. That helper returns the current frame payload size, not the DMA mapping size. On the TX path, tbstream_dev_alloc_tx() stores a shorter payload length in frame.size when the payload is smaller than TB_MAX_FRAME_SIZE. This happens for a short final DATA frame, and also for the CLOSE frame, which is allocated with SZ_256. In those cases the buffer was mapped with TB_MAX_FRAME_SIZE, but tb_ring_frame_size() returns the shorter frame payload length. This makes the dma_unmap_page() size differ from the original dma_map_page() size. Use TB_MAX_FRAME_SIZE when unmapping stream buffers so the unmap size matches the DMA mapping size used by the buffer allocation paths. Signed-off-by: Xu Rao Fixes: 6db21d817b43 ("thunderbolt: Add support for USB4STREAM") Signed-off-by: Mika Westerberg --- drivers/thunderbolt/stream.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/thunderbolt') diff --git a/drivers/thunderbolt/stream.c b/drivers/thunderbolt/stream.c index c1f5c55583d0..4cc86d8d6491 100644 --- a/drivers/thunderbolt/stream.c +++ b/drivers/thunderbolt/stream.c @@ -257,7 +257,7 @@ static void tbstream_ring_free(struct tbstream_ring *ring) if (sf->frame.buffer_phy) dma_unmap_page(dma_dev, sf->frame.buffer_phy, - tb_ring_frame_size(&sf->frame), dir); + TB_MAX_FRAME_SIZE, dir); sf->frame.buffer_phy = 0; if (sf->page) __free_page(sf->page); -- cgit v1.2.3