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authorAdrian Hunter <adrian.hunter@intel.com>2017-04-20 16:14:43 +0800
committerUlf Hansson <ulf.hansson@linaro.org>2017-04-24 21:42:27 +0200
commit83b600b8de0e83661a8f40091a7966fac052a21b (patch)
tree4a4763e27e7814c3693c0449a9b8517def13c2da /drivers/mmc/host/sdhci.c
parentba49cbd0936e12eac245c0fb420a291e8505f639 (diff)
downloadop-kernel-dev-83b600b8de0e83661a8f40091a7966fac052a21b.zip
op-kernel-dev-83b600b8de0e83661a8f40091a7966fac052a21b.tar.gz
mmc: sdhci: Control the delay between tuning commands
The delay between tuning commands for SD cards is not part of the specification. A driver that needs it probably needs it for eMMC too, whereas most drivers would probably like to set it to 0. Make it a host member (host->tuning_delay) that defaults to the existing behaviour. Drivers can set it to zero to eliminate the delay, or set it to a positive value to always have a delay. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc/host/sdhci.c')
-rw-r--r--drivers/mmc/host/sdhci.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 4bdad89..ecd0d43 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2108,9 +2108,9 @@ static void __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
break;
}
- /* eMMC spec does not require a delay between tuning cycles */
- if (opcode == MMC_SEND_TUNING_BLOCK)
- mdelay(1);
+ /* Spec does not require a delay between tuning cycles */
+ if (host->tuning_delay > 0)
+ mdelay(host->tuning_delay);
}
pr_info("%s: Tuning failed, falling back to fixed sampling clock\n",
@@ -2172,6 +2172,9 @@ int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
host->mmc->retune_period = tuning_count;
+ if (host->tuning_delay < 0)
+ host->tuning_delay = opcode == MMC_SEND_TUNING_BLOCK;
+
sdhci_start_tuning(host);
__sdhci_execute_tuning(host, opcode);
@@ -3114,6 +3117,8 @@ struct sdhci_host *sdhci_alloc_host(struct device *dev,
host->cqe_ier = SDHCI_CQE_INT_MASK;
host->cqe_err_ier = SDHCI_CQE_INT_ERR_MASK;
+ host->tuning_delay = -1;
+
return host;
}
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