[PATCH 0/3] mmc: meson-gx: fixes for v4.14

[PATCH 0/3] mmc: meson-gx: fixes for v4.14

[Jerome Brunet]

This patchset fixes the issues reported by Heiner [0] with the odroid-c2.
In a nutshell, this series does the following:

* Make sure the mmc clock rate is not set higher than what is requested
* Reset the tuning values on mmc power cycle instead of POWER_ON
* Add tuning of the tx phase to the tuning function.

This fixes the problem seen on the odroid-c2, both for hs200 and hs400.
To check for regression, this series has also been tested on the gxl
libretech-cc

Ulf, could you please pick this as fixes for v4.14 ?

[0]: https://lkml.kernel.org/r/e2171288-84ef-82db-2efc-300935e6c062@gmail.com

Jerome Brunet (3):
  mmc: meson-gx: make sure the clock is rounded down
  mmc: meson-gx: fix rx phase reset
  mmc: meson-gx: include tx phase in the tuning process

 drivers/mmc/host/meson-gx-mmc.c | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

-- 
2.13.5

[PATCH 1/3] mmc: meson-gx: make sure the clock is rounded down

[Jerome Brunet]

Using CLK_DIVIDER_ROUND_CLOSEST is unsafe as the mmc clock could be
rounded to a rate higher the specified rate. Removing this flag ensure
that, if the rate needs to be rounded, it will be rounded down.

Fixes: 51c5d8447bd7 ("MMC: meson: initial support for GX platforms")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/mmc/host/meson-gx-mmc.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index c885c2d4b904..421c8719c202 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -531,8 +531,7 @@ static int meson_mmc_clk_init(struct meson_host *host)
 	div->shift = __ffs(CLK_DIV_MASK);
 	div->width = __builtin_popcountl(CLK_DIV_MASK);
 	div->hw.init = &init;
-	div->flags = (CLK_DIVIDER_ONE_BASED |
-		      CLK_DIVIDER_ROUND_CLOSEST);
+	div->flags = CLK_DIVIDER_ONE_BASED;
 
 	clk = devm_clk_register(host->dev, &div->hw);
 	if (WARN_ON(IS_ERR(clk)))
-- 
2.13.5

[PATCH 2/3] mmc: meson-gx: fix rx phase reset

[Jerome Brunet]

Resetting the phase when POWER_ON is set the set_ios() call means that the
phase is reset almost every time the set_ios() is called, while the
expected behavior was to reset the phase on a power cycle.

This had gone unnoticed until now because in all mode (except hs400) the
tuning is done after the last to set_ios(). In such case, the tuning
result is used anyway.  In HS400, there are a few calls to set_ios() after
the tuning is done, overwriting the tuning result.

Resetting the phase on POWER_UP instead of POWER_ON solve the problem.

Fixes: d341ca88eead ("mmc: meson-gx: rework tuning function")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/mmc/host/meson-gx-mmc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 421c8719c202..08a55c2e96e1 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -745,6 +745,10 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 	case MMC_POWER_UP:
 		if (!IS_ERR(mmc->supply.vmmc))
 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
+
+		/* Reset rx phase */
+		clk_set_phase(host->rx_clk, 0);
+
 		break;
 
 	case MMC_POWER_ON:
@@ -758,8 +762,6 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 				host->vqmmc_enabled = true;
 		}
 
-		/* Reset rx phase */
-		clk_set_phase(host->rx_clk, 0);
 		break;
 	}
 
-- 
2.13.5

[PATCH 3/3] mmc: meson-gx: include tx phase in the tuning process

[Jerome Brunet]

It has been reported that some platforms (odroid-c2) may require
a different tx phase setting to operate at high speed (hs200 and hs400)

To improve the situation, this patch includes tx phase in the tuning
process.

Fixes: d341ca88eead ("mmc: meson-gx: rework tuning function")
Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/mmc/host/meson-gx-mmc.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 08a55c2e96e1..85745ef179e2 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -716,6 +716,22 @@ 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);
 }
@@ -746,8 +762,9 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		if (!IS_ERR(mmc->supply.vmmc))
 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
 
-		/* Reset rx phase */
+		/* Reset phases */
 		clk_set_phase(host->rx_clk, 0);
+		clk_set_phase(host->tx_clk, 270);
 
 		break;
 
-- 
2.13.5

Re: [PATCH 0/3] mmc: meson-gx: fixes for v4.14

[Kevin Hilman]

Jerome Brunet <jbrunet@baylibre.com> writes:

> This patchset fixes the issues reported by Heiner [0] with the odroid-c2.
> In a nutshell, this series does the following:
>
> * Make sure the mmc clock rate is not set higher than what is requested
> * Reset the tuning values on mmc power cycle instead of POWER_ON
> * Add tuning of the tx phase to the tuning function.
>
> This fixes the problem seen on the odroid-c2, both for hs200 and hs400.
> To check for regression, this series has also been tested on the gxl
> libretech-cc
>
> Ulf, could you please pick this as fixes for v4.14 ?
>
> [0]: https://lkml.kernel.org/r/e2171288-84ef-82db-2efc-300935e6c062@gmail.com
>
> Jerome Brunet (3):
>   mmc: meson-gx: make sure the clock is rounded down
>   mmc: meson-gx: fix rx phase reset
>   mmc: meson-gx: include tx phase in the tuning process
>
>  drivers/mmc/host/meson-gx-mmc.c | 26 ++++++++++++++++++++++----
>  1 file changed, 22 insertions(+), 4 deletions(-)

Reviewed-by: Kevin Hilman <khilman@baylibre.com>

Re: [PATCH 0/3] mmc: meson-gx: fixes for v4.14

[Ulf Hansson]

On 2 October 2017 at 14:27, Jerome Brunet <jbrunet@baylibre.com> wrote:
> This patchset fixes the issues reported by Heiner [0] with the odroid-c2.
> In a nutshell, this series does the following:
>
> * Make sure the mmc clock rate is not set higher than what is requested
> * Reset the tuning values on mmc power cycle instead of POWER_ON
> * Add tuning of the tx phase to the tuning function.
>
> This fixes the problem seen on the odroid-c2, both for hs200 and hs400.
> To check for regression, this series has also been tested on the gxl
> libretech-cc
>
> Ulf, could you please pick this as fixes for v4.14 ?

Thanks, applied for fixes!

Kind regards
Uffe

>
> [0]: https://lkml.kernel.org/r/e2171288-84ef-82db-2efc-300935e6c062@gmail.com
>
> Jerome Brunet (3):
>   mmc: meson-gx: make sure the clock is rounded down
>   mmc: meson-gx: fix rx phase reset
>   mmc: meson-gx: include tx phase in the tuning process
>
>  drivers/mmc/host/meson-gx-mmc.c | 26 ++++++++++++++++++++++----
>  1 file changed, 22 insertions(+), 4 deletions(-)
>
> --
> 2.13.5
>