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From: Myeonghun Pak <mhun512@gmail.com>
To: Mark Brown <broonie@kernel.org>, Heiko Stuebner <heiko@sntech.de>
Cc: linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Ijae Kim <ae878000@gmail.com>
Subject: [PATCH v2] spi: rockchip-sfc: skip DMA cleanup in PIO mode
Date: Sat, 12 Sep 2026 15:00:56 -0400	[thread overview]
Message-ID: <20260912190056.42192-1-mhun512@gmail.com> (raw)
In-Reply-To: <aqRM17TZ0-5pd6Y0@sirena.org.uk>

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 <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
---
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

WARNING: multiple messages have this Message-ID (diff)
From: Myeonghun Pak <mhun512@gmail.com>
To: Mark Brown <broonie@kernel.org>, Heiko Stuebner <heiko@sntech.de>
Cc: linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Ijae Kim <ae878000@gmail.com>
Subject: [PATCH v2] spi: rockchip-sfc: skip DMA cleanup in PIO mode
Date: Sat, 12 Sep 2026 15:00:56 -0400	[thread overview]
Message-ID: <20260912190056.42192-1-mhun512@gmail.com> (raw)
In-Reply-To: <aqRM17TZ0-5pd6Y0@sirena.org.uk>

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 <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
---
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

_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip

  reply	other threads:[~2026-09-12 19:01 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-11 17:27 [PATCH] spi: rockchip-sfc: skip DMA cleanup in PIO mode Myeonghun Pak
2026-09-11 17:27 ` Myeonghun Pak
2026-09-11 18:47 ` Mark Brown
2026-09-11 18:47   ` Mark Brown
2026-09-12 19:00   ` Myeonghun Pak [this message]
2026-09-12 19:00     ` [PATCH v2] " Myeonghun Pak
2026-09-13 11:34     ` Mark Brown
2026-09-13 11:34       ` Mark Brown
2026-09-13 20:31       ` Myeonghun Pak
2026-09-13 20:31         ` Myeonghun Pak
2026-09-24 23:03     ` Mark Brown
2026-09-24 23:03       ` Mark Brown

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