From: Yoshihiro Shimoda Date: Fri, 20 Oct 2017 03:12:42 +0000 (+0900) Subject: mmc: renesas_sdhi: fix kernel panic in _internal_dmac.c X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=48e1dc10a9440872c0fc07a7fbcfce177f996fd4;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git mmc: renesas_sdhi: fix kernel panic in _internal_dmac.c Since this driver checks if the return value of dma_map_sg() is minus or not and keeps to enable the DMAC, it may cause kernel panic when the dma_map_sg() returns 0. So, this patch fixes the issue. Reported-by: Dirk Behme Fixes: 2a68ea7896e3 ("mmc: renesas-sdhi: add support for R-Car Gen3 SDHI DMAC") Signed-off-by: Yoshihiro Shimoda Reviewed-by: Geert Uytterhoeven Acked-by: Wolfram Sang Signed-off-by: Ulf Hansson --- diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c index f905f2361d12..8bae88a150fd 100644 --- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c +++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c @@ -146,11 +146,8 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host, WARN_ON(host->sg_len > 1); /* This DMAC cannot handle if buffer is not 8-bytes alignment */ - if (!IS_ALIGNED(sg->offset, 8)) { - host->force_pio = true; - renesas_sdhi_internal_dmac_enable_dma(host, false); - return; - } + if (!IS_ALIGNED(sg->offset, 8)) + goto force_pio; if (data->flags & MMC_DATA_READ) { dtran_mode |= DTRAN_MODE_CH_NUM_CH1; @@ -163,8 +160,8 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host, } ret = dma_map_sg(&host->pdev->dev, sg, host->sg_len, dir); - if (ret < 0) - return; + if (ret == 0) + goto force_pio; renesas_sdhi_internal_dmac_enable_dma(host, true); @@ -176,6 +173,12 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host, dtran_mode); renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR, sg->dma_address); + + return; + +force_pio: + host->force_pio = true; + renesas_sdhi_internal_dmac_enable_dma(host, false); } static void renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)