From 83b600b8de0e83661a8f40091a7966fac052a21b Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Thu, 20 Apr 2017 16:14:43 +0800 Subject: 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 Signed-off-by: Yangbo Lu Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'drivers/mmc/host/sdhci.c') 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; } -- cgit v1.1