From 31e75ed964582257f59156ce6a42860e1ae4cc39 Mon Sep 17 00:00:00 2001 From: Erick Shepherd Date: Fri, 14 Mar 2025 14:50:21 -0500 Subject: [PATCH] mmc: host: Wait for Vdd to settle on card power off The SD spec version 6.0 section 6.4.1.5 requires that Vdd must be lowered to less than 0.5V for a minimum of 1 ms when powering off a card. Increase wait to 15 ms so that voltage has time to drain down to 0.5V and cards can power off correctly. Issues with voltage drain time were only observed on Apollo Lake and Bay Trail host controllers so this fix is limited to those devices. Signed-off-by: Erick Shepherd Acked-by: Adrian Hunter Link: https://lore.kernel.org/r/20250314195021.1588090-1-erick.shepherd@ni.com Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci-pci-core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c index 1f0bd723f0112..13a84b9309e06 100644 --- a/drivers/mmc/host/sdhci-pci-core.c +++ b/drivers/mmc/host/sdhci-pci-core.c @@ -610,8 +610,12 @@ static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode, sdhci_set_power(host, mode, vdd); - if (mode == MMC_POWER_OFF) + if (mode == MMC_POWER_OFF) { + if (slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_APL_SD || + slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_BYT_SD) + usleep_range(15000, 17500); return; + } /* * Bus power might not enable after D3 -> D0 transition due to the -- 2.47.2