[PATCH V6 7/9] mmc: sdhci: SDMA may use Auto-CMD23 in v4 mode

[Chunyan Zhang]

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@xxxxxxxxxx>
---
 drivers/mmc/host/sdhci.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 7e01601..1cb55f2 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3828,10 +3828,14 @@ 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->v4_mode && !(host->flags & SDHCI_USE_SDMA)) ||
+	     (host->v4_mode && (host->flags & SDHCI_USE_SDMA))) &&
 	     !(host->quirks2 & SDHCI_QUIRK2_ACMD23_BROKEN)) {
 		host->flags |= SDHCI_AUTO_CMD23;
 		DBG("Auto-CMD23 available\n");
-- 
2.7.4