diff options
| author | Sujit Reddy Thumma <sthumma@codeaurora.org> | 2014-01-21 17:22:05 +0530 |
|---|---|---|
| committer | Subhash Jadavani <subhashj@codeaurora.org> | 2016-05-27 10:29:00 -0700 |
| commit | d621731e5f48f9fc29c5058163e7668b63060f9e (patch) | |
| tree | 20b3ca880f1d4173439ac021839edee4658372e4 /drivers | |
| parent | d90d5901faba22e9bc67ade166de12b63412c44c (diff) | |
mmc: sdhci: Fix possible spec. violation during voltage switch sequence
With commit 0797e5f145 (mmc: core: Fixup signal voltage switch), voltage
switch sequence for UHS-I cards is broken if used with sdhci driver.
The commit expects the SD clock to be disabled when mmc_set_ios() is
issued but sdhci_do_set_ios() re-enables the SD clock for few cycles
after disabling which is a specification violation during voltage
switch sequence. This failure is observed only for a small group of
cards where they ultimately fall-back into high-speed mode even if
UHS-I modes are supported.
Change-Id: Ie275326627a84bfcd4352637a043296c01c175a6
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mmc/host/sdhci.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 34678c4e9c31..022c6319a0c8 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1814,7 +1814,8 @@ static void sdhci_do_set_ios(struct sdhci_host *host, struct mmc_ios *ios) sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL); /* Re-enable SD Clock */ - host->ops->set_clock(host, host->clock); + if (ios->clock) + host->ops->set_clock(host, host->clock); } /* Reset SD Clock Enable */ @@ -1841,7 +1842,8 @@ static void sdhci_do_set_ios(struct sdhci_host *host, struct mmc_ios *ios) } /* Re-enable SD Clock */ - host->ops->set_clock(host, host->clock); + if (ios->clock) + host->ops->set_clock(host, host->clock); } else sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL); |