staging: mt7621-mmc: Check for nonzero number of scatterlist entries (d4223e06) · Commits · 戴 / test

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 <thirtythreeforty@gmail.com> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/mt7621-mmc/sd.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -591,8 +591,6 @@ 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;

		@@ -681,6 +679,13 @@ 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);

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