[ Upstream commit d4223e06b6aed581625f574ad8faa71b6c0fc903 ] The buffer descriptor setup loop is correct only if it is setting up at least one bd struct. Besides, there is an error if dma_map_sg() returns 0, which is possible and must be handled.
Additionally, remove the BUG_ON() checking sglen, which is unnecessary because we configure DMA with that constraint during init. Signed-off-by: George Hilliard <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- drivers/staging/mt7621-mmc/sd.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/staging/mt7621-mmc/sd.c b/drivers/staging/mt7621-mmc/sd.c index 74f0e57ad2f15..38f9ea02ee3a9 100644 --- a/drivers/staging/mt7621-mmc/sd.c +++ b/drivers/staging/mt7621-mmc/sd.c @@ -596,8 +596,6 @@ static void msdc_dma_setup(struct msdc_host *host, struct msdc_dma *dma, struct bd *bd; u32 j; - BUG_ON(sglen > MAX_BD_NUM); /* not support currently */ - gpd = dma->gpd; bd = dma->bd; @@ -692,6 +690,13 @@ static int msdc_do_request(struct mmc_host *mmc, struct mmc_request *mrq) data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len, mmc_get_dma_dir(data)); + + if (data->sg_count == 0) { + dev_err(mmc_dev(host->mmc), "failed to map DMA for transfer\n"); + data->error = -ENOMEM; + goto done; + } + msdc_dma_setup(host, &host->dma, data->sg, data->sg_count); -- 2.20.1
