It has been reported that some platforms (odroid-c2) may require
a different tx phase setting to operate at high speed.
To improve the situation, this patch includes tx phase in the tuning
process.
Reported-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
---
Hi Heiner,
Would you mind trying this change with your setup and letting us know
if it helps ?
It seems like a good idea to add an initial Rx tuning before doing the
actual tuning but, honestly, I don't know if it is really necessary.
Regards
Jerome
drivers/mmc/host/meson-gx-mmc.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index c885c2d4b904..0254d8bfd536 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -717,6 +717,22 @@ static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode,
static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
{
struct meson_host *host = mmc_priv(mmc);
+ int ret;
+
+ /*
+ * If this is the initial tuning, try to get a sane Rx starting
+ * phase before doing the actual tuning.
+ */
+ if (!mmc->doing_retune) {
+ ret = meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
+
+ if (ret)
+ return ret;
+ }
+
+ ret = meson_mmc_clk_phase_tuning(mmc, opcode, host->tx_clk);
+ if (ret)
+ return ret;
return meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
}
--
2.13.5
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