Commit 1dc5a615 authored by Ulf Hansson's avatar Ulf Hansson
Browse files

mmc: sdio: Align the initialization commands in retry path for UHS-I 



According to the comment in mmc_sdio_reinit_card(), some SDIO cards may
require a "[CMD5,5,3,7] init sequence", which isn't always obeyed in
mmc_sdio_init_card(). Especially, when we end up retrying the UHS-I
specific initialization, there is a missing CMD5.

Let's update the code to make the behaviour consistent and let's also take
the opportunity to clean up the code a bit, to avoid open coding.

Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20200430091640.455-5-ulf.hansson@linaro.org
parent fa1e3191

drivers/mmc/core/sdio.c

+26 −27
Original line number Diff line number Diff line
@@ -543,13 +543,33 @@ out: 
	return err;

}



static void mmc_sdio_resend_if_cond(struct mmc_host *host, u32 ocr,

static int mmc_sdio_pre_init(struct mmc_host *host, u32 ocr,

			     struct mmc_card *card)

{

	if (card)

		mmc_remove_card(card);



	/*

	 * Reset the card by performing the same steps that are taken by

	 * mmc_rescan_try_freq() and mmc_attach_sdio() during a "normal" probe.

	 *

	 * sdio_reset() is technically not needed. Having just powered up the

	 * hardware, it should already be in reset state. However, some

	 * platforms (such as SD8686 on OLPC) do not instantly cut power,

	 * meaning that a reset is required when restoring power soon after

	 * powering off. It is harmless in other cases.

	 *

	 * The CMD5 reset (mmc_send_io_op_cond()), according to the SDIO spec,

	 * is not necessary for non-removable cards. However, it is required

	 * for OLPC SD8686 (which expects a [CMD5,5,3,7] init sequence), and

	 * harmless in other situations.

	 *

	 */



	sdio_reset(host);

	mmc_go_idle(host);

	mmc_send_if_cond(host, ocr);

	mmc_remove_card(card);

	return mmc_send_io_op_cond(host, 0, NULL);

}



/*
@@ -640,7 +660,7 @@ try_again: 
	if (rocr & ocr & R4_18V_PRESENT) {

		err = mmc_set_uhs_voltage(host, ocr_card);

		if (err == -EAGAIN) {

			mmc_sdio_resend_if_cond(host, ocr_card, card);

			mmc_sdio_pre_init(host, ocr_card, card);

			retries--;

			goto try_again;

		} else if (err) {
@@ -712,7 +732,7 @@ try_again: 
	 */

	err = sdio_read_cccr(card, ocr);

	if (err) {

		mmc_sdio_resend_if_cond(host, ocr_card, card);

		mmc_sdio_pre_init(host, ocr_card, card);

		if (ocr & R4_18V_PRESENT) {

			/* Retry init sequence, but without R4_18V_PRESENT. */

			retries = 0;
@@ -813,28 +833,7 @@ static int mmc_sdio_reinit_card(struct mmc_host *host) 
{

	int ret;



	/*

	 * Reset the card by performing the same steps that are taken by

	 * mmc_rescan_try_freq() and mmc_attach_sdio() during a "normal" probe.

	 *

	 * sdio_reset() is technically not needed. Having just powered up the

	 * hardware, it should already be in reset state. However, some

	 * platforms (such as SD8686 on OLPC) do not instantly cut power,

	 * meaning that a reset is required when restoring power soon after

	 * powering off. It is harmless in other cases.

	 *

	 * The CMD5 reset (mmc_send_io_op_cond()), according to the SDIO spec,

	 * is not necessary for non-removable cards. However, it is required

	 * for OLPC SD8686 (which expects a [CMD5,5,3,7] init sequence), and

	 * harmless in other situations.

	 *

	 */



	sdio_reset(host);

	mmc_go_idle(host);

	mmc_send_if_cond(host, host->card->ocr);



	ret = mmc_send_io_op_cond(host, 0, NULL);

	ret = mmc_sdio_pre_init(host, host->card->ocr, NULL);

	if (ret)

		return ret;

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