Thanks to ian@ who experimented a lot with his TI PCI7621 SDHC, we know

that the controller "kind-of" works, but it does not indicate completion
of the host controller reset.  Thus we cannot know whether the reset was
successful or not, so don't return an error if the reset timed out.

1 files changed, 15 insertions, 14 deletions

diff --git a/sys/dev/sdmmc/sdhc.c b/sys/dev/sdmmc/sdhc.c
index df97eac4fd7..ba1d0d55fe2 100644
--- a/sys/dev/sdmmc/sdhc.c
+++ b/sys/dev/sdmmc/sdhc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sdhc.c,v 1.4 2006/06/02 20:03:05 uwe Exp $	*/
+/*	$OpenBSD: sdhc.c,v 1.5 2006/06/29 01:32:33 uwe Exp $	*/
 
 /*
  * Copyright (c) 2006 Uwe Stuehler <uwe@openbsd.org>
@@ -105,7 +105,7 @@ void	sdhc_command_timeout(void *);
 void	sdhc_dump_regs(struct sdhc_host *);
 #define DPRINTF(s)	printf s
 #else
-#define DPRINTF(s)	/**/
+#define DPRINTF(s)	do {} while(0)
 #endif
 
 struct sdmmc_chip_functions sdhc_functions = {
@@ -176,10 +176,7 @@ sdhc_host_found(struct sdhc_softc *sc, bus_space_tag_t iot,
 	/*
 	 * Reset the host controller and enable interrupts.
 	 */
-	if (sdhc_host_reset(hp) != 0) {
-		printf("%s: host reset failed\n", sc->sc_dev.dv_xname);
-		goto err;
-	}
+	(void)sdhc_host_reset(hp);
 
 	/* Determine host capabilities. */
 	caps = HREAD4(hp, SDHC_CAPABILITIES);
@@ -358,6 +355,7 @@ sdhc_power(int why, void *arg)
 		/* Restore the host controller state. */
 		for (n = 0; n < sc->sc_nhosts; n++) {
 			hp = &sc->sc_host[n];
+			(void)sdhc_host_reset(hp);
 			for (i = 0; i < sizeof hp->regs; i++)
 				HWRITE1(hp, i, hp->regs[i]);
 		}
@@ -378,20 +376,23 @@ sdhc_shutdown(void *arg)
 	/* XXX chip locks up if we don't disable it before reboot. */
 	for (i = 0; i < sc->sc_nhosts; i++) {
 		hp = &sc->sc_host[i];
-		sdhc_host_reset(hp);
+		(void)sdhc_host_reset(hp);
 	}
 }
 
 /*
  * Reset the host controller.  Called during initialization, when
- * cards are removed and during error recovery.
+ * cards are removed, upon resume, and during error recovery.
+ *
+ * Unfortunately, at least one vendor does not follow the simplified
+ * SDHC specification: TI's PCI7621 does not clear reset bits, so we
+ * have no way to tell whether the reset was successful or timed out.
  */
 int
 sdhc_host_reset(sdmmc_chipset_handle_t sch)
 {
 	struct sdhc_host *hp = sch;
 	u_int16_t imask;
-	int error = 0;
 	int timo;
 	int s;
 
@@ -401,7 +402,8 @@ sdhc_host_reset(sdmmc_chipset_handle_t sch)
 	HWRITE2(hp, SDHC_NINTR_SIGNAL_EN, 0);
 
 	/*
-	 * Reset the entire host controller and wait up to 100ms.
+	 * Reset the entire host controller and wait up to 100ms for
+	 * the controller to clear the reset bit.
 	 */
 	HWRITE1(hp, SDHC_SOFTWARE_RESET, SDHC_RESET_MASK);
 	for (timo = 10; timo > 0; timo--) {
@@ -411,7 +413,7 @@ sdhc_host_reset(sdmmc_chipset_handle_t sch)
 	}
 	if (timo == 0) {
 		HWRITE1(hp, SDHC_SOFTWARE_RESET, 0);
-		error = ETIMEDOUT;
+		/* return ETIMEDOUT; but see above. */
 	}
 
 	/* Set data timeout counter value to max for now. */
@@ -428,7 +430,7 @@ sdhc_host_reset(sdmmc_chipset_handle_t sch)
 	HWRITE2(hp, SDHC_EINTR_SIGNAL_EN, SDHC_EINTR_SIGNAL_MASK);
 
 	splx(s);
-	return error;
+	return 0;
 }
 
 u_int32_t
@@ -477,8 +479,7 @@ sdhc_bus_power(sdmmc_chipset_handle_t sch, u_int32_t ocr)
 	/* If power is disabled, reset the host and return now. */
 	if (ocr == 0) {
 		splx(s);
-		if (sdhc_host_reset(hp) != 0)
-			DPRINTF(("%s: host reset failed\n", HDEVNAME(hp)));
+		(void)sdhc_host_reset(hp);
 		return 0;
 	}