git: bd15d31cef50 - main - mmc(4): Don't call bridge driver for timings not requiring tuning

The branch main has been updated by marius:

URL: https://cgit.FreeBSD.org/src/commit/?id=bd15d31cef50060d90356384ba7b878d398fc9f3

commit bd15d31cef50060d90356384ba7b878d398fc9f3
Author:     Marius Strobl <marius@FreeBSD.org>
AuthorDate: 2023-04-12 21:46:02 +0000
Commit:     Marius Strobl <marius@FreeBSD.org>
CommitDate: 2023-04-18 17:17:24 +0000

    mmc(4): Don't call bridge driver for timings not requiring tuning
    
    The original idea behind calling into the bridge driver was to have the
    logic deciding whether tuning is actually required for a particular bus
    timing in a given slot as well as doing the sanity checking only on the
    controller layer which also generally is better suited for these due to
    say SDHCI_SDR50_NEEDS_TUNING. On another thought, not every such driver
    should need to check whether tuning is required at all, though, and not
    everything is SDHCI in the first place.
    Adjust sdhci{,_fsl_fdt}(4) accordingly, but keep sdhci_generic_tune() a
    bit cautious still.
---
 sys/dev/mmc/mmc.c             |  9 +++++++++
 sys/dev/sdhci/sdhci.c         |  6 ++++--
 sys/dev/sdhci/sdhci_fsl_fdt.c | 17 +++--------------
 3 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/sys/dev/mmc/mmc.c b/sys/dev/mmc/mmc.c
index 5fce6cbf47a1..54caadb2b3c7 100644
--- a/sys/dev/mmc/mmc.c
+++ b/sys/dev/mmc/mmc.c
@@ -2237,6 +2237,15 @@ clock:
 		mmcbr_set_clock(dev, max_dtr);
 		mmcbr_update_ios(dev);
 
+		/*
+		 * Don't call into the bridge driver for timings definitely
+		 * not requiring tuning.  Note that it's up to the upper
+		 * layer to actually execute tuning otherwise.
+		 */
+		if (timing <= bus_timing_uhs_sdr25 ||
+		    timing == bus_timing_mmc_ddr52)
+			goto power_class;
+
 		if (mmcbr_tune(dev, hs400) != 0) {
 			device_printf(dev, "Card at relative address %d "
 			    "failed to execute initial tuning\n", rca);
diff --git a/sys/dev/sdhci/sdhci.c b/sys/dev/sdhci/sdhci.c
index a7283e66df31..69dbd3d7ffd7 100644
--- a/sys/dev/sdhci/sdhci.c
+++ b/sys/dev/sdhci/sdhci.c
@@ -1492,10 +1492,12 @@ sdhci_generic_tune(device_t brdev __unused, device_t reqdev, bool hs400)
 	case bus_timing_uhs_sdr50:
 		if (slot->opt & SDHCI_SDR50_NEEDS_TUNING)
 			break;
-		/* FALLTHROUGH */
-	default:
 		SDHCI_UNLOCK(slot);
 		return (0);
+	default:
+		slot_printf(slot, "Tuning requested but not required.\n");
+		SDHCI_UNLOCK(slot);
+		return (EINVAL);
 	}
 
 	tune_cmd = slot->tune_cmd;
diff --git a/sys/dev/sdhci/sdhci_fsl_fdt.c b/sys/dev/sdhci/sdhci_fsl_fdt.c
index 470cbd169303..2c600e1291fe 100644
--- a/sys/dev/sdhci/sdhci_fsl_fdt.c
+++ b/sys/dev/sdhci/sdhci_fsl_fdt.c
@@ -1199,22 +1199,10 @@ sdhci_fsl_fdt_tune(device_t bus, device_t child, bool hs400)
 
 	sc = device_get_softc(bus);
 	slot = device_get_ivars(child);
-	error = 0;
-	clk_divider = sc->baseclk_hz / slot->clock;
 
-	switch (sc->slot.host.ios.timing) {
-	case bus_timing_mmc_hs400:
-		return (EINVAL);
-	case bus_timing_mmc_hs200:
-	case bus_timing_uhs_ddr50:
-	case bus_timing_uhs_sdr104:
-		break;
-	case bus_timing_uhs_sdr50:
-		if (slot->opt & SDHCI_SDR50_NEEDS_TUNING)
-			break;
-	default:
+	if (sc->slot.host.ios.timing == bus_timing_uhs_sdr50 &&
+	    !(slot->opt & SDHCI_SDR50_NEEDS_TUNING))
 		return (0);
-	}
 
 	/*
 	 * For tuning mode SD clock divider must be within 3 to 16.
@@ -1222,6 +1210,7 @@ sdhci_fsl_fdt_tune(device_t bus, device_t child, bool hs400)
 	 * For that reason we're just bailing if the dividers don't match
 	 * that requirement.
 	 */
+	clk_divider = sc->baseclk_hz / slot->clock;
 	if (clk_divider < 3 || clk_divider > 16)
 		return (ENXIO);