2015-08-18 1:11 GMT+08:00 Ulf Hansson [off-list ref]:

On 11 August 2015 at 10:41, Barry Song [off-list ref] wrote:

quoted

From: Weijun Yang <redacted>

As SD Specifications Part1 Physical Layer Specification Version
3.01 says, CMD19 tuning is available for unlocked cards in transfer
state of 1.8V signaling mode. The small difference between v3.00
and 3.01 spec means that CMD19 tuning is also available for DDR50
mode.

So what happens with cards following the 3.0 spec version, those
doesn't need to support the tuning CMD right? Perhaps that needs to be
addressed in this patch well!?

from HW registers of the card, we cann't know whether the HW needs
tuning. it is said 3.0.x need tuning, but 3.0 doesn't need.  @weijun,
pls fix me if i am wrong.
if so, it seems we need a static flag somewhere to indicate whether
the tuning is needed. we can't detect to find the tuning requirement.

Kind regards
Uffe

quoted

Signed-off-by: Weijun Yang <redacted>
Signed-off-by: Barry Song <redacted>
---
 drivers/mmc/core/sd.c    | 1 +
 drivers/mmc/host/sdhci.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 4e7366a..a1ed24d 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c

@@ -629,6 +629,7 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card)
         */
        if (!mmc_host_is_spi(card->host) &&
            (card->sd_bus_speed == UHS_SDR50_BUS_SPEED ||
+            card->sd_bus_speed == UHS_DDR50_BUS_SPEED ||
             card->sd_bus_speed == UHS_SDR104_BUS_SPEED))
                err = mmc_execute_tuning(card);
 out:

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 1dbe932..812c19b 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c

@@ -1891,6 +1891,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
                break;

        case MMC_TIMING_UHS_SDR104:
+       case MMC_TIMING_UHS_DDR50:
                break;

        case MMC_TIMING_UHS_SDR50:
--

1.9.1

-barry