diff options
| author | Gwendal Grignou <gwendal@chromium.org> | 2016-04-01 23:04:22 (GMT) |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2016-05-02 08:33:24 (GMT) |
| commit | 4e6c71788d6bb0e5438fc9211fa6e52dcca01474 (patch) | |
| tree | ae5fce16a3076b11bd1803d67f1c61f48192dd1d | |
| parent | 6aef2eecc4d4c9edb8c8d3e3a7f6af3cee42b2ec (diff) | |
| download | linux-4e6c71788d6bb0e5438fc9211fa6e52dcca01474.tar.xz | |
mmc: core: Do regular power cycle when lacking eMMC HW reset support
The eMMC HW reset may be implemented either via the host ops ->hw_reset()
callback or through DT and the eMMC pwrseq. Additionally some eMMC cards
don't support HW reset.
To allow a reset to be done for the different combinations of mmc hosts
and eMMC/MMC cards, let's implement a fallback via trying a regular power
cycle. This improves the mmc block layer retry mechanism of failing I/O
requests.
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
[Ulf: Rewrote changelog]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
| -rw-r--r-- | drivers/mmc/core/core.c | 5 | ||||
| -rw-r--r-- | 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 f80b3ab..99275e4 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2456,8 +2456,9 @@ 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 4dbe3df..b8aa12c 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1957,19 +1957,17 @@ 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); } |