mmc: jz4740_mmc: Fix error check for dma_map_sg

dma_map_sg return 0 on error.

Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Acked-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220825074008.33349-3-jinpu.wang@ionos.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/jz4740_mmc.c b/drivers/mmc/host/jz4740_mmc.c
index b1d563b..dc2db9c 100644 (file)
--- a/drivers/mmc/host/jz4740_mmc.c
+++ b/drivers/mmc/host/jz4740_mmc.c
@@ -298,7 +298,7 @@ static int jz4740_mmc_prepare_dma_data(struct jz4740_mmc_host *host,
 {
        struct dma_chan *chan = jz4740_mmc_get_dma_chan(host, data);
        enum dma_data_direction dir = mmc_get_dma_dir(data);
-       int sg_count;
+       unsigned int sg_count;
 
        if (data->host_cookie == COOKIE_PREMAPPED)
                return data->sg_count;
@@ -308,7 +308,7 @@ static int jz4740_mmc_prepare_dma_data(struct jz4740_mmc_host *host,
                        data->sg_len,
                        dir);
 
-       if (sg_count <= 0) {
+       if (!sg_count) {
                dev_err(mmc_dev(host->mmc),
                        "Failed to map scatterlist for DMA operation\n");
                return -EINVAL;