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 | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 62d843ac90..606d331 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -3834,10 +3834,13 @@ 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"); -- 2.7.4