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Commit 4324f6de authored by Weijun Yang's avatar Weijun Yang Committed by Ulf Hansson
Browse files

mmc: core: enable CMD19 tuning for DDR50 mode 



As SD Specifications Part1 Physical Layer Specification Version
3.01 says, CMD19 tuning is available for unlocked cards in transfer
state of 1.8V signaling mode. The small difference between v3.00
and 3.01 spec means that CMD19 tuning is also available for DDR50
mode.

Signed-off-by: default avatarWeijun Yang <york.yang@csr.com>
Signed-off-by: default avatarBarry Song <Baohua.Song@csr.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent b093410c

drivers/mmc/core/sd.c

+18 −2
Original line number Diff line number Diff line
@@ -627,8 +627,24 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card) 
	 */

	if (!mmc_host_is_spi(card->host) &&

		(card->sd_bus_speed == UHS_SDR50_BUS_SPEED ||

	     card->sd_bus_speed == UHS_SDR104_BUS_SPEED))

		 card->sd_bus_speed == UHS_DDR50_BUS_SPEED ||

		 card->sd_bus_speed == UHS_SDR104_BUS_SPEED)) {

		err = mmc_execute_tuning(card);



		/*

		 * As SD Specifications Part1 Physical Layer Specification

		 * Version 3.01 says, CMD19 tuning is available for unlocked

		 * cards in transfer state of 1.8V signaling mode. The small

		 * difference between v3.00 and 3.01 spec means that CMD19

		 * tuning is also available for DDR50 mode.

		 */

		if (err && card->sd_bus_speed == UHS_DDR50_BUS_SPEED) {

			pr_warn("%s: ddr50 tuning failed\n",

				mmc_hostname(card->host));

			err = 0;

		}

	}



out:

	kfree(status);