Turning on CONFIG_DMA_API_DEBUG_SG results in the following warning: WARNING: CPU: 1 PID: 85 at kernel/dma/debug.c:1302 debug_dma_map_sg+0x2a0/0x3cc mmci-pl18x 58005000.sdmmc: DMA-API: mapping sg segment longer than device claims to support [len=126976] [max=65536] dma api debug checks and compares the segment size to dma_get_max_seg_size (dev->dma_parms->max_segment_size), the sdmmc variant has an internal DMA and should define its max_segment_size constraint to avoid this warning. This Patch defines the dev->dma_parms->max_segment_size with the constraint already set for mmc core (host->mmc->max_seg_size). Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx> --- drivers/mmc/host/mmci_stm32_sdmmc.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/mmc/host/mmci_stm32_sdmmc.c b/drivers/mmc/host/mmci_stm32_sdmmc.c index 2965b1c062e1..51db30acf4dc 100644 --- a/drivers/mmc/host/mmci_stm32_sdmmc.c +++ b/drivers/mmc/host/mmci_stm32_sdmmc.c @@ -119,20 +119,19 @@ static void sdmmc_idma_unprep_data(struct mmci_host *host, static int sdmmc_idma_setup(struct mmci_host *host) { struct sdmmc_idma *idma; + struct device *dev = mmc_dev(host->mmc); - idma = devm_kzalloc(mmc_dev(host->mmc), sizeof(*idma), GFP_KERNEL); + idma = devm_kzalloc(dev, sizeof(*idma), GFP_KERNEL); if (!idma) return -ENOMEM; host->dma_priv = idma; if (host->variant->dma_lli) { - idma->sg_cpu = dmam_alloc_coherent(mmc_dev(host->mmc), - SDMMC_LLI_BUF_LEN, + idma->sg_cpu = dmam_alloc_coherent(dev, SDMMC_LLI_BUF_LEN, &idma->sg_dma, GFP_KERNEL); if (!idma->sg_cpu) { - dev_err(mmc_dev(host->mmc), - "Failed to alloc IDMA descriptor\n"); + dev_err(dev, "Failed to alloc IDMA descriptor\n"); return -ENOMEM; } host->mmc->max_segs = SDMMC_LLI_BUF_LEN / @@ -143,7 +142,7 @@ static int sdmmc_idma_setup(struct mmci_host *host) host->mmc->max_seg_size = host->mmc->max_req_size; } - return 0; + return dma_set_max_seg_size(dev, host->mmc->max_seg_size); } static int sdmmc_idma_start(struct mmci_host *host, unsigned int *datactrl) -- 2.17.1