Commit 63f15609 authored by Adrian Hunter's avatar Adrian Hunter Committed by Ulf Hansson
Browse files

mmc: core: Fix inconsistent sd3_bus_mode at UHS-I SD voltage switch failure 



If re-initialization results is a different signal voltage, because the
voltage switch failed previously, but not this time (or vice versa), then
sd3_bus_mode will be inconsistent with the card because the SD_SWITCH
command is done only upon first initialization.

Fix by always reading SD_SWITCH information during re-initialization, which
also means it does not need to be re-read later for the 1.8V fixup
workaround.

Note, brief testing showed SD_SWITCH took about 1.8ms to 2ms which added
about 1% to 1.5% to the re-initialization time, so it's not particularly
significant.

Reported-by: default avatarSeunghui Lee <sh043.lee@samsung.com>
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: default avatarSeunghui Lee <sh043.lee@samsung.com>
Tested-by: default avatarSeunghui Lee <sh043.lee@samsung.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220815073321.63382-3-adrian.hunter@intel.com


Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 15c56208

drivers/mmc/core/sd.c

+16 −26
Original line number Diff line number Diff line
@@ -949,14 +949,15 @@ int mmc_sd_setup_card(struct mmc_host *host, struct mmc_card *card, 


		/* Erase init depends on CSD and SSR */

		mmc_init_erase(card);

	}



	/*

		 * Fetch switch information from card.

	 * Fetch switch information from card. Note, sd3_bus_mode can change if

	 * voltage switch outcome changes, so do this always.

	 */

	err = mmc_read_switch(card);

	if (err)

		return err;

	}



	/*

	 * For SPI, enable CRC as appropriate.
@@ -1480,16 +1481,6 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr, 
	if (!v18_fixup_failed && !mmc_host_is_spi(host) && mmc_host_uhs(host) &&

	    mmc_sd_card_using_v18(card) &&

	    host->ios.signal_voltage != MMC_SIGNAL_VOLTAGE_180) {

		/*

		 * Re-read switch information in case it has changed since

		 * oldcard was initialized.

		 */

		if (oldcard) {

			err = mmc_read_switch(card);

			if (err)

				goto free_card;

		}

		if (mmc_sd_card_using_v18(card)) {

		if (mmc_host_set_uhs_voltage(host) ||

		    mmc_sd_init_uhs_card(card)) {

			v18_fixup_failed = true;
@@ -1500,7 +1491,6 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr, 
		}

		goto cont;

	}

	}



	/* Initialization sequence for UHS-I cards */

	if (rocr & SD_ROCR_S18A && mmc_host_uhs(host)) {