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 <dirk.behme@de.bosch.com>
Fixes: 2a68ea7896 ("mmc: renesas-sdhi: add support for R-Car Gen3 SDHI DMAC")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Yoshihiro Shimoda 2017-10-20 12:12:42 +09:00 committed by Ulf Hansson
parent e90e8da72a
commit 48e1dc10a9

View File

@ -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)