Diff below addresses issue with Intel SD controllers
failing to enable SD cards and eMMC devices.

  sdmmc0: can't enable card

This happens after sdmmc(4) makes a bus_power request for the
same voltage that the card is currently operating.

Change sdhc_bus_power() behavior to return successfully and not
do a power-off voltage switch sequence if both conditions are met:
 1) bus is powered on.
 2) bus is already at requested voltage.

With this change we can zap the Intel NOPWR0 quirk.

Tested on 400-series-LP (SD) and Apollo Lake (SD*,eMMC) SoCs.
(* card probed only at boot; needs GPIO card detect interrupt.)

ok?


Index: dev/sdmmc/sdhc.c
===================================================================
RCS file: /cvs/src/sys/dev/sdmmc/sdhc.c,v
retrieving revision 1.77
diff -u -p -r1.77 sdhc.c
--- dev/sdmmc/sdhc.c	6 Aug 2024 15:03:36 -0000	1.77
+++ dev/sdmmc/sdhc.c	20 Sep 2024 09:30:06 -0000
@@ -591,14 +591,9 @@ sdhc_bus_power(sdmmc_chipset_handle_t sc
 
 	s = splsdmmc();
 
-	/*
-	 * Disable bus power before voltage change.
-	 */
-	if (!(hp->sc->sc_flags & SDHC_F_NOPWR0))
-		HWRITE1(hp, SDHC_POWER_CTL, 0);
-
 	/* If power is disabled, reset the host and return now. */
 	if (ocr == 0) {
+		HWRITE1(hp, SDHC_POWER_CTL, 0);
 		splx(s);
 		(void)sdhc_host_reset(hp);
 		return 0;
@@ -619,6 +614,21 @@ sdhc_bus_power(sdmmc_chipset_handle_t sc
 		splx(s);
 		return EINVAL;
 	}
+
+	/*
+	 * Return if no change to powered bus voltage.
+	 */
+	if (HREAD1(hp, SDHC_POWER_CTL) ==
+	    ((vdd << SDHC_VOLTAGE_SHIFT) | SDHC_BUS_POWER)) {
+		splx(s);
+		return 0;
+	}
+
+	/*
+	 * Disable bus power before voltage change.
+	 */
+	if (!(hp->sc->sc_flags & SDHC_F_NOPWR0))
+		HWRITE1(hp, SDHC_POWER_CTL, 0);
 
 	/*
 	 * Enable bus power.  Wait at least 1 ms (or 74 clocks) plus
Index: dev/pci/sdhc_pci.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/sdhc_pci.c,v
retrieving revision 1.26
diff -u -p -r1.26 sdhc_pci.c
--- dev/pci/sdhc_pci.c	29 Mar 2024 02:36:49 -0000	1.26
+++ dev/pci/sdhc_pci.c	20 Sep 2024 09:30:06 -0000
@@ -126,16 +126,6 @@ sdhc_pci_attach(struct device *parent, s
 	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_ENE_SDCARD)
 		sc->sc.sc_flags |= SDHC_F_NOPWR0;
 
-	/* Some Intel controllers break if set to 0V bus power. */
-	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_INTEL &&
-	    (PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_INTEL_100SERIES_LP_EMMC ||
-	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_INTEL_APOLLOLAKE_EMMC ||
-	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_INTEL_GLK_EMMC ||
-	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_INTEL_JSL_EMMC ||
-	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_INTEL_EHL_EMMC ||
-	    PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_INTEL_ADL_N_EMMC))
-		sc->sc.sc_flags |= SDHC_F_NOPWR0;
-
 	/* Some RICOH controllers need to be bumped into the right mode. */
 	if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_RICOH &&
 	    (PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_RICOH_R5U822 ||