openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

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: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20200430091640.455-5-ulf.hansson@linaro.org
This commit is contained in:
Ulf Hansson 2020-04-30 11:16:40 +02:00
parent fa1e319192
commit 1dc5a61559
1 changed files with 26 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
drivers/mmc/core/sdio.c
View File

@ -543,13 +543,33 @@ static int mmc_sdio_init_uhs_card(struct mmc_card *card)
return err; 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) 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); sdio_reset(host);
mmc_go_idle(host); mmc_go_idle(host);
mmc_send_if_cond(host, ocr); mmc_send_if_cond(host, ocr);
mmc_remove_card(card); return mmc_send_io_op_cond(host, 0, NULL);
} }
/* /*
@ -640,7 +660,7 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
if (rocr & ocr & R4_18V_PRESENT) { if (rocr & ocr & R4_18V_PRESENT) {
err = mmc_set_uhs_voltage(host, ocr_card); err = mmc_set_uhs_voltage(host, ocr_card);
if (err == -EAGAIN) { if (err == -EAGAIN) {
mmc_sdio_resend_if_cond(host, ocr_card, card); mmc_sdio_pre_init(host, ocr_card, card);
retries--; retries--;
goto try_again; goto try_again;
} else if (err) { } else if (err) {
@ -712,7 +732,7 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
*/ */
err = sdio_read_cccr(card, ocr); err = sdio_read_cccr(card, ocr);
if (err) { if (err) {
mmc_sdio_resend_if_cond(host, ocr_card, card); mmc_sdio_pre_init(host, ocr_card, card);
if (ocr & R4_18V_PRESENT) { if (ocr & R4_18V_PRESENT) {
/* Retry init sequence, but without R4_18V_PRESENT. */ /* Retry init sequence, but without R4_18V_PRESENT. */
retries = 0; retries = 0;
@ -813,28 +833,7 @@ static int mmc_sdio_reinit_card(struct mmc_host *host)
{ {
int ret; int ret;
/* ret = mmc_sdio_pre_init(host, host->card->ocr, NULL);
* 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);
if (ret) if (ret)
return ret; return ret;