From 7bda9482e7ed4d27d83c1f9cb5cbe3b34ddac3e8 Mon Sep 17 00:00:00 2001
From: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Date: Fri, 22 Mar 2019 12:38:05 +0100
Subject: [PATCH] mmc: sdhci-of-arasan: Add DTS property to disable DCMDs.
Direct commands (DCMDs) are an optional feature of eMMC 5.1's command
queue engine (CQE). The Arasan eMMC 5.1 controller uses the CQHCI,
which exposes a control register bit to enable the feature.
The current implementation sets this bit unconditionally.
This patch allows to suppress the feature activation,
by specifying the property disable-cqe-dcmd.
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Fixes: 84362d79f436 ("mmc: sdhci-of-arasan: Add CQHCI support for arasan,sdhci-5.1")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
drivers/mmc/host/sdhci-of-arasan.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index c9e3e050ccc86..88dc3f00a5be7 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -832,7 +832,10 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
host->mmc_host_ops.start_signal_voltage_switch =
sdhci_arasan_voltage_switch;
sdhci_arasan->has_cqe = true;
- host->mmc->caps2 |= MMC_CAP2_CQE | MMC_CAP2_CQE_DCMD;
+ host->mmc->caps2 |= MMC_CAP2_CQE;
+
+ if (!of_property_read_bool(np, "disable-cqe-dcmd"))
+ host->mmc->caps2 |= MMC_CAP2_CQE_DCMD;
}
ret = sdhci_arasan_add_host(sdhci_arasan);
--
2.30.2