On 2016/8/31 13:51, Jaehoon Chung wrote:
HS400 mode doesn't need to do execute_tuning, because it's already
tuned in HS200 mode. And Tuning command is optional for UHS50 mode.
In future, the general execute_tuning sequence can be included in this
function.
Maybe this isn't what we want for mmc.
I see both of sd and sdio call mmc_execute_tuning by checking
the ios.timing, and explicitly we need to do tuning for
MMC_TIMING_UHS_SDR50 as the mmc core asks we to do that.
Moreover, why mmc didn't do something like:
if (card->host->ios.timing == MMC_TIMING_XXXXX || ....)
mmc_execute_tuning()
So we don't need every host driver to add these check and I do
see some host drivers check these timing for their execute_tuning
callback..
What is your opinion? :)
Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
---
drivers/mmc/host/dw_mmc.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 22dacae..6571924 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1568,10 +1568,25 @@ static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)
struct dw_mci_slot *slot = mmc_priv(mmc);
struct dw_mci *host = slot->host;
const struct dw_mci_drv_data *drv_data = host->drv_data;
- int err = -EINVAL;
+ int err = 0;
+
+ switch (host->timing) {
+ case MMC_TIMING_MMC_HS400:
+ err = -EINVAL;
+ goto out;
+ case MMC_TIMING_MMC_HS200:
+ case MMC_TIMING_UHS_SDR104:
+ case MMC_TIMING_UHS_DDR50:
+ break;
+ case MMC_TIMING_UHS_SDR50:
+ /* Fall through */
+ default:
+ goto out;
+ }
if (drv_data && drv_data->execute_tuning)
err = drv_data->execute_tuning(slot, opcode);
+out:
return err;
}
--
Best Regards
Shawn Lin
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