From 78a90a1e489e3f19b0adf8327f432ee0684a7680 Mon Sep 17 00:00:00 2001 From: Sia Jee Heng Date: Mon, 25 Jan 2021 09:32:54 +0800 Subject: [PATCH] dmaengine: dw-axi-dmac: Set constraint to the Max segment size Add support for DMA Scatter-Gather (SG) constraint so that DMA clients can handle the AxiDMA limitation. Without supporting DMA constraint the default Max segment size reported by dmaengine is 64KB, which is not supported by Intel KeemBay AxiDMA. Signed-off-by: Sia Jee Heng Tested-by: Eugeniy Paltsev Reviewed-by: Andy Shevchenko Reviewed-by: Eugeniy Paltsev Link: https://lore.kernel.org/r/20210125013255.25799-17-jee.heng.sia@intel.com Signed-off-by: Vinod Koul --- drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 8 ++++++++ drivers/dma/dw-axi-dmac/dw-axi-dmac.h | 1 + 2 files changed, 9 insertions(+) diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c index a1dddec95316a..88d4923dee6c5 100644 --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -1340,6 +1341,13 @@ static int dw_probe(struct platform_device *pdev) dw->dma.device_prep_slave_sg = dw_axi_dma_chan_prep_slave_sg; dw->dma.device_prep_dma_cyclic = dw_axi_dma_chan_prep_cyclic; + /* + * Synopsis DesignWare AxiDMA datasheet mentioned Maximum + * supported blocks is 1024. Device register width is 4 bytes. + * Therefore, set constraint to 1024 * 4. + */ + dw->dma.dev->dma_parms = &dw->dma_parms; + dma_set_max_seg_size(&pdev->dev, MAX_BLOCK_SIZE); platform_set_drvdata(pdev, chip); pm_runtime_enable(chip->dev); diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h index 3a357f7fda024..1e937ea2a96de 100644 --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h @@ -54,6 +54,7 @@ struct axi_dma_chan { struct dw_axi_dma { struct dma_device dma; struct dw_axi_dma_hcfg *hdata; + struct device_dma_parameters dma_parms; /* channels */ struct axi_dma_chan *chan;