Commit cb962e04 authored by Ulf Hansson's avatar Ulf Hansson Committed by Chris Ball
Browse files

mmc: core: Respect host's max_busy_timeout when sending sleep cmd 



When sending the sleep command for host drivers supporting
MMC_CAP_WAIT_WHILE_BUSY, we need to confirm that max_busy_timeout is
big enough comparing to the sleep timeout specified from card's
EXT_CSD. If this isn't case, we use a R1 response instead of R1B and
fallback to use a delay instead.

Do note that a max_busy_timeout set to zero by the host, is interpreted
as it can cope with whatever timeout the mmc core provides it with.

Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: default avatarChris Ball <chris@printf.net>
parent 57de31f6

drivers/mmc/core/mmc.c

+16 −3
Original line number Diff line number Diff line
@@ -1358,6 +1358,7 @@ static int mmc_sleep(struct mmc_host *host) 
{

	struct mmc_command cmd = {0};

	struct mmc_card *card = host->card;

	unsigned int timeout_ms = DIV_ROUND_UP(card->ext_csd.sa_timeout, 10000);

	int err;



	err = mmc_deselect_cards(host);
@@ -1368,7 +1369,19 @@ static int mmc_sleep(struct mmc_host *host) 
	cmd.arg = card->rca << 16;

	cmd.arg |= 1 << 15;



	/*

	 * If the max_busy_timeout of the host is specified, validate it against

	 * the sleep cmd timeout. A failure means we need to prevent the host

	 * from doing hw busy detection, which is done by converting to a R1

	 * response instead of a R1B.

	 */

	if (host->max_busy_timeout && (timeout_ms > host->max_busy_timeout)) {

		cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;

	} else {

		cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;

		cmd.busy_timeout = timeout_ms;

	}



	err = mmc_wait_for_cmd(host, &cmd, 0);

	if (err)

		return err;
@@ -1379,8 +1392,8 @@ static int mmc_sleep(struct mmc_host *host) 
	 * SEND_STATUS command to poll the status because that command (and most

	 * others) is invalid while the card sleeps.

	 */

	if (!(host->caps & MMC_CAP_WAIT_WHILE_BUSY))

		mmc_delay(DIV_ROUND_UP(card->ext_csd.sa_timeout, 10000));

	if (!cmd.busy_timeout || !(host->caps & MMC_CAP_WAIT_WHILE_BUSY))

		mmc_delay(timeout_ms);



	return err;

}

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