From 2cb535529d52658613a2138677f5e497e633bead Mon Sep 17 00:00:00 2001 From: Javier Martin Date: Tue, 30 Oct 2012 16:54:07 +0100 Subject: [PATCH] mmc: mxcmmc: fix SD cards not being detected sometimes. When a SD card is initialized some data transfers of 64 and 8 bytes are issued. It seems the DMA has some problems dealing with these kind of "short" transfers, leading sometimes to the SD card not being detected. In order to solve this problem, do not use DMA for transfer sizes lower than the sector size. Signed-off-by: Javier Martin Acked-by: Sascha Hauer Signed-off-by: Chris Ball --- drivers/mmc/host/mxcmmc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c index 6290b7f1ccfe..29e680f193a0 100644 --- a/drivers/mmc/host/mxcmmc.c +++ b/drivers/mmc/host/mxcmmc.c @@ -240,7 +240,7 @@ static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data) return 0; for_each_sg(data->sg, sg, data->sg_len, i) { - if (sg->offset & 3 || sg->length & 3) { + if (sg->offset & 3 || sg->length & 3 || sg->length < 512) { host->do_dma = 0; return 0; } -- 2.20.1