From: Christoph Muellner christoph.muellner@theobroma-systems.com
commit 7bda9482e7ed4d27d83c1f9cb5cbe3b34ddac3e8 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mmc/host/sdhci-of-arasan.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- 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 pla 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);