mmc: sdhci: SDMA may use Auto-CMD23 in v4 mode

When Host Version 4 Enable is set to 1, SDMA uses ADMA System Address
register (05Fh-058h) instead of using register (000h-004h) to indicate
its system address of data location. The register (000h-004h) is
re-assigned to 32-bit Block Count and Auto CMD23 argument, so then SDMA
may use Auto CMD23.
Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci.c

@@ -3844,10 +3844,13 @@ int sdhci_setup_host(struct sdhci_host *host)
 	if (host->quirks & SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12)
 		host->flags |= SDHCI_AUTO_CMD12;
 
-	/* Auto-CMD23 stuff only works in ADMA or PIO. */
+	/*
+	 * For v3 mode, Auto-CMD23 stuff only works in ADMA or PIO.
+	 * For v4 mode, SDMA may use Auto-CMD23 as well.
+	 */
 	if ((host->version >= SDHCI_SPEC_300) &&
 	    ((host->flags & SDHCI_USE_ADMA) ||
-	     !(host->flags & SDHCI_USE_SDMA)) &&
+	     !(host->flags & SDHCI_USE_SDMA) || host->v4_mode) &&
 	     !(host->quirks2 & SDHCI_QUIRK2_ACMD23_BROKEN)) {
 		host->flags |= SDHCI_AUTO_CMD23;
 		DBG("Auto-CMD23 available\n");