[PATCH v2] spi: rockchip-sfc: skip DMA cleanup in PIO mode
From: Myeonghun Pak <hidden>
Date: 2026-09-12 19:01:18
Also in:
linux-rockchip, linux-spi, lkml
Subsystem:
arm/rockchip soc support, spi subsystem, the rest · Maintainers:
Heiko Stuebner, Mark Brown, Linus Torvalds
With rockchip,sfc-no-dma, probe skips allocating and mapping the transfer
buffer. However, controller registration failure and driver removal still
call dma_unmap_single() for that nonexistent mapping.
Guard the DMA mapping and buffer cleanup with use_dma. Keep the existing
cleanup for allocation and mapping failures on the DMA path.
This issue was identified during our ongoing static-analysis research while
reviewing kernel code.
Fixes: ee795e82e101 ("spi: rockchip-sfc: Fix DMA-API usage")
Assisted-by: OpenAI:GPT-5.6
Co-developed-by: Ijae Kim <redacted>
Signed-off-by: Ijae Kim <redacted>
Signed-off-by: Myeonghun Pak <redacted>
---
Changes in v2:
- Guard the cleanup calls directly instead of jumping between error labels,
as suggested by Mark Brown.
drivers/spi/spi-rockchip-sfc.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/spi/spi-rockchip-sfc.c b/drivers/spi/spi-rockchip-sfc.c
index 662a994da60beca33358dc6af09017e88771d017..bc5537aee449e0c33c2d6ecf9d57205d432ec7b6 100644
--- a/drivers/spi/spi-rockchip-sfc.c
+++ b/drivers/spi/spi-rockchip-sfc.c@@ -719,10 +719,12 @@ static int rockchip_sfc_probe(struct platform_device *pdev) return 0; err_register: - dma_unmap_single(dev, sfc->dma_buffer, sfc->max_iosize, - DMA_BIDIRECTIONAL); + if (sfc->use_dma) + dma_unmap_single(dev, sfc->dma_buffer, sfc->max_iosize, + DMA_BIDIRECTIONAL); err_dma_map: - free_pages((unsigned long)sfc->buffer, get_order(sfc->max_iosize)); + if (sfc->use_dma) + free_pages((unsigned long)sfc->buffer, get_order(sfc->max_iosize)); err_dma: pm_runtime_get_sync(dev); pm_runtime_put_noidle(dev);
@@ -743,9 +745,11 @@ static void rockchip_sfc_remove(struct platform_device *pdev) struct spi_controller *host = sfc->host; spi_unregister_controller(host); - dma_unmap_single(&pdev->dev, sfc->dma_buffer, sfc->max_iosize, - DMA_BIDIRECTIONAL); - free_pages((unsigned long)sfc->buffer, get_order(sfc->max_iosize)); + if (sfc->use_dma) { + dma_unmap_single(&pdev->dev, sfc->dma_buffer, sfc->max_iosize, + DMA_BIDIRECTIONAL); + free_pages((unsigned long)sfc->buffer, get_order(sfc->max_iosize)); + } clk_disable_unprepare(sfc->clk); clk_disable_unprepare(sfc->hclk);
--
2.53.0