mmc: dw_mmc: fix the max_blk_count in IDMAC

Even though 1MB is reserved for descriptor table in IDMAC,
the dw_mmc host driver is allowed to receive only maximum
128KB block length in one request. This is caused by setting
improper max_blk_count. It needs to be e adjusted so that
descriptor table is used fully. It is found that the performance
is improved with the increased the max_blk_count.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/dw_mmc.c

@@ -2332,9 +2332,9 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
 #ifdef CONFIG_MMC_DW_IDMAC
 		mmc->max_segs = host->ring_size;
 		mmc->max_blk_size = 65536;
-		mmc->max_blk_count = host->ring_size;
 		mmc->max_seg_size = 0x1000;
-		mmc->max_req_size = mmc->max_seg_size * mmc->max_blk_count;
+		mmc->max_req_size = mmc->max_seg_size * host->ring_size;
+		mmc->max_blk_count = mmc->max_req_size / 512;
 #else
 		mmc->max_segs = 64;
 		mmc->max_blk_size = 65536; /* BLKSIZ is 16 bits */