Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

mmc: mmci_sdmmc: fix DMA API warning max segment size

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@st.com>
Link: https://lore.kernel.org/r/20200526155103.12514-3-ludovic.barre@st.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

authored by

Ludovic Barre and committed by
Ulf Hansson
942d5e7b fe8d33bd

+5 -6
+5 -6
drivers/mmc/host/mmci_stm32_sdmmc.c
··· 119 119 static int sdmmc_idma_setup(struct mmci_host *host) 120 120 { 121 121 struct sdmmc_idma *idma; 122 + struct device *dev = mmc_dev(host->mmc); 122 123 123 - idma = devm_kzalloc(mmc_dev(host->mmc), sizeof(*idma), GFP_KERNEL); 124 + idma = devm_kzalloc(dev, sizeof(*idma), GFP_KERNEL); 124 125 if (!idma) 125 126 return -ENOMEM; 126 127 127 128 host->dma_priv = idma; 128 129 129 130 if (host->variant->dma_lli) { 130 - idma->sg_cpu = dmam_alloc_coherent(mmc_dev(host->mmc), 131 - SDMMC_LLI_BUF_LEN, 131 + idma->sg_cpu = dmam_alloc_coherent(dev, SDMMC_LLI_BUF_LEN, 132 132 &idma->sg_dma, GFP_KERNEL); 133 133 if (!idma->sg_cpu) { 134 - dev_err(mmc_dev(host->mmc), 135 - "Failed to alloc IDMA descriptor\n"); 134 + dev_err(dev, "Failed to alloc IDMA descriptor\n"); 136 135 return -ENOMEM; 137 136 } 138 137 host->mmc->max_segs = SDMMC_LLI_BUF_LEN / ··· 142 143 host->mmc->max_seg_size = host->mmc->max_req_size; 143 144 } 144 145 145 - return 0; 146 + return dma_set_max_seg_size(dev, host->mmc->max_seg_size); 146 147 } 147 148 148 149 static int sdmmc_idma_start(struct mmci_host *host, unsigned int *datactrl)