From: Guodong Xu Date: Thu, 18 Sep 2025 14:27:27 +0000 (+0800) Subject: dmaengine: mmp_pdma: fix DMA mask handling X-Git-Tag: v6.19-rc6~4^2~24 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=49400b701eca849c1b53717b1f5d779a8d066ec0;p=thirdparty%2Flinux.git dmaengine: mmp_pdma: fix DMA mask handling The driver's existing logic for setting the DMA mask for "marvell,pdma-1.0" was flawed. It incorrectly relied on pdev->dev->coherent_dma_mask instead of declaring the hardware's fixed addressing capability. A cleaner and more correct approach is to define the mask directly based on the hardware limitations. The MMP/PXA PDMA controller is a 32-bit DMA engine. This is supported by datasheets and various dtsi files for PXA25x, PXA27x, PXA3xx, and MMP2, all of which are 32-bit systems. This patch simplifies the driver's logic by replacing the 'u64 dma_mask' field with a simpler 'u32 dma_width' to store the addressing capability in bits. The complex if/else block in probe() is then replaced with a single, clear call to dma_set_mask_and_coherent(). This sets a fixed 32-bit DMA mask for "marvell,pdma-1.0" and a 64-bit mask for "spacemit,k1-pdma," matching each device's hardware capabilities. Finally, this change also works around a specific build error encountered with clang-20 on x86_64 allyesconfig. The shift-count-overflow error is caused by a known clang compiler issue where the DMA_BIT_MASK(n) macro's ternary operator is not correctly evaluated in static initializers. By moving the macro's evaluation into the probe() function, the driver avoids this compiler bug. Fixes: 5cfe585d8624 ("dmaengine: mmp_pdma: Add SpacemiT K1 PDMA support with 64-bit addressing") Reported-by: Naresh Kamboju Closes: https://lore.kernel.org/lkml/CA+G9fYsPcMfW-e_0_TRqu4cnwqOqYF3aJOeKUYk6Z4qRStdFvg@mail.gmail.com Suggested-by: Arnd Bergmann Signed-off-by: Guodong Xu Reviewed-by: Arnd Bergmann Tested-by: Nathan Chancellor # build Tested-by: Naresh Kamboju Signed-off-by: Vinod Koul --- diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index d07229a74886..86661eb3cde1 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -152,8 +152,8 @@ struct mmp_pdma_phy { * * Controller Configuration: * @run_bits: Control bits in DCSR register for channel start/stop - * @dma_mask: DMA addressing capability of controller. 0 to use OF/platform - * settings, or explicit mask like DMA_BIT_MASK(32/64) + * @dma_width: DMA addressing width in bits (32 or 64). Determines the + * DMA mask capability of the controller hardware. */ struct mmp_pdma_ops { /* Hardware Register Operations */ @@ -173,7 +173,7 @@ struct mmp_pdma_ops { /* Controller Configuration */ u32 run_bits; - u64 dma_mask; + u32 dma_width; }; struct mmp_pdma_device { @@ -1172,7 +1172,7 @@ static const struct mmp_pdma_ops marvell_pdma_v1_ops = { .get_desc_src_addr = get_desc_src_addr_32, .get_desc_dst_addr = get_desc_dst_addr_32, .run_bits = (DCSR_RUN), - .dma_mask = 0, /* let OF/platform set DMA mask */ + .dma_width = 32, }; static const struct mmp_pdma_ops spacemit_k1_pdma_ops = { @@ -1185,7 +1185,7 @@ static const struct mmp_pdma_ops spacemit_k1_pdma_ops = { .get_desc_src_addr = get_desc_src_addr_64, .get_desc_dst_addr = get_desc_dst_addr_64, .run_bits = (DCSR_RUN | DCSR_LPAEEN), - .dma_mask = DMA_BIT_MASK(64), /* force 64-bit DMA addr capability */ + .dma_width = 64, }; static const struct of_device_id mmp_pdma_dt_ids[] = { @@ -1314,13 +1314,9 @@ static int mmp_pdma_probe(struct platform_device *op) pdev->device.directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM); pdev->device.residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; - /* Set DMA mask based on ops->dma_mask, or OF/platform */ - if (pdev->ops->dma_mask) - dma_set_mask(pdev->dev, pdev->ops->dma_mask); - else if (pdev->dev->coherent_dma_mask) - dma_set_mask(pdev->dev, pdev->dev->coherent_dma_mask); - else - dma_set_mask(pdev->dev, DMA_BIT_MASK(64)); + /* Set DMA mask based on controller hardware capabilities */ + dma_set_mask_and_coherent(pdev->dev, + DMA_BIT_MASK(pdev->ops->dma_width)); ret = dma_async_device_register(&pdev->device); if (ret) {