When the eMMC device does not support/allow sending RST_n signal,
try to do a brute force power cycle instead of returning EOPNOTSUPP.
If power cycle is not supported by the hardware, mmc_init_card still
send a CMD0, performing a Software Reset.
Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
---
Changes in v3:
- clock setting in already done in power_cycle.
- clarify behavior when power cycle is not implemented. .
drivers/mmc/core/core.c | 5 +++--
drivers/mmc/core/mmc.c | 24 +++++++++++-------------
2 files changed, 14 insertions(+), 15 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index d8bbc78..d5bc2d8 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2468,8 +2468,9 @@ int mmc_hw_reset(struct mmc_host *host)
ret = host->bus_ops->reset(host);
mmc_bus_put(host);
- if (ret != -EOPNOTSUPP)
- pr_warn("%s: tried to reset card\n", mmc_hostname(host));
+ if (ret)
+ pr_warn("%s: tried to reset card, got error %d\n",
+ mmc_hostname(host), ret);
return ret;
}
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 96cc7e2..92b7bea 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1988,19 +1988,17 @@ static int mmc_reset(struct mmc_host *host)
{
struct mmc_card *card = host->card;
- if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->hw_reset)
- return -EOPNOTSUPP;
-
- if (!mmc_can_reset(card))
- return -EOPNOTSUPP;
-
- mmc_set_clock(host, host->f_init);
-
- host->ops->hw_reset(host);
-
- /* Set initial state and call mmc_set_ios */
- mmc_set_initial_state(host);
-
+ if ((host->caps & MMC_CAP_HW_RESET) && host->ops->hw_reset &&
+ mmc_can_reset(card)) {
+ /* If the card accept RST_n signal, send it. */
+ mmc_set_clock(host, host->f_init);
+ host->ops->hw_reset(host);
+ /* Set initial state and call mmc_set_ios */
+ mmc_set_initial_state(host);
+ } else {
+ /* Do a brute force power cycle */
+ mmc_power_cycle(host, card->ocr);
+ }
return mmc_init_card(host, card->ocr, card);
}
--
2.8.0.rc3.226.g39d4020
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
