2022-01-11 09:53:19

by Amjad Ouled-Ameur

[permalink] [raw]
Subject: [PATCH v6 0/3] phy: amlogic: fix shared reset control use

This patchset fixes a usb suspend warning seen on the libretech-cc by
using reset_control_rearm() call of the reset framework API.
This call allows a reset consummer to release the reset line even when
just triggered so that it may be triggered again by other reset
consummers.

reset_control_(de)assert() calls are called, in some meson usb drivers,
on a shared reset line when reset_control_reset has been used. This is not
allowed by the reset framework.

Finally the meson usb drivers are updated to use this new call, which
solves the suspend issue addressed by the previous reverted
commit 7a410953d1fb ("usb: dwc3: meson-g12a: fix shared reset control
use").

changes since v5:
- No changes.

Amjad Ouled-Ameur (3):
phy: amlogic: phy-meson-gxl-usb2: fix shared reset controller use
phy: amlogic: meson8b-usb2: Use dev_err_probe()
phy: amlogic: meson8b-usb2: fix shared reset control use

drivers/phy/amlogic/phy-meson-gxl-usb2.c | 5 ++++-
drivers/phy/amlogic/phy-meson8b-usb2.c | 9 +++++++--
2 files changed, 11 insertions(+), 3 deletions(-)

--
2.25.1



2022-01-11 09:53:26

by Amjad Ouled-Ameur

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Subject: [PATCH v6 1/3] phy: amlogic: phy-meson-gxl-usb2: fix shared reset controller use

Use reset_control_rearm() call if an error occurs in case
phy_meson_gxl_usb2_init() fails after reset() has been called ; or in case
phy_meson_gxl_usb2_exit() is called i.e the resource is no longer used
and the reset line may be triggered again by other devices.

reset_control_rearm() keeps use of triggered_count sane in the reset
framework. Therefore, use of reset_control_reset() on shared reset line
should be balanced with reset_control_rearm().

Signed-off-by: Amjad Ouled-Ameur <[email protected]>
Reported-by: Jerome Brunet <[email protected]>
Reviewed-by: Martin Blumenstingl <[email protected]>
Reviewed-by: Philipp Zabel <[email protected]>
Acked-by: Neil Armstrong <[email protected]>
---
drivers/phy/amlogic/phy-meson-gxl-usb2.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/amlogic/phy-meson-gxl-usb2.c b/drivers/phy/amlogic/phy-meson-gxl-usb2.c
index 2b3c0d730f20..db17c3448bfe 100644
--- a/drivers/phy/amlogic/phy-meson-gxl-usb2.c
+++ b/drivers/phy/amlogic/phy-meson-gxl-usb2.c
@@ -114,8 +114,10 @@ static int phy_meson_gxl_usb2_init(struct phy *phy)
return ret;

ret = clk_prepare_enable(priv->clk);
- if (ret)
+ if (ret) {
+ reset_control_rearm(priv->reset);
return ret;
+ }

return 0;
}
@@ -125,6 +127,7 @@ static int phy_meson_gxl_usb2_exit(struct phy *phy)
struct phy_meson_gxl_usb2_priv *priv = phy_get_drvdata(phy);

clk_disable_unprepare(priv->clk);
+ reset_control_rearm(priv->reset);

return 0;
}
--
2.25.1


2022-01-11 09:53:31

by Amjad Ouled-Ameur

[permalink] [raw]
Subject: [PATCH v6 2/3] phy: amlogic: meson8b-usb2: Use dev_err_probe()

Use the existing dev_err_probe() helper instead of open-coding the same
operation.

Signed-off-by: Amjad Ouled-Ameur <[email protected]>
Reported-by: Martin Blumenstingl <[email protected]>
Reviewed-by: Martin Blumenstingl <[email protected]>
Acked-by: Neil Armstrong <[email protected]>
---
drivers/phy/amlogic/phy-meson8b-usb2.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/amlogic/phy-meson8b-usb2.c b/drivers/phy/amlogic/phy-meson8b-usb2.c
index cf10bed40528..77e7e9b1428c 100644
--- a/drivers/phy/amlogic/phy-meson8b-usb2.c
+++ b/drivers/phy/amlogic/phy-meson8b-usb2.c
@@ -265,8 +265,9 @@ static int phy_meson8b_usb2_probe(struct platform_device *pdev)
return PTR_ERR(priv->clk_usb);

priv->reset = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
- if (PTR_ERR(priv->reset) == -EPROBE_DEFER)
- return PTR_ERR(priv->reset);
+ if (IS_ERR(priv->reset))
+ return dev_err_probe(&pdev->dev, PTR_ERR(priv->reset),
+ "Failed to get the reset line");

priv->dr_mode = of_usb_get_dr_mode_by_phy(pdev->dev.of_node, -1);
if (priv->dr_mode == USB_DR_MODE_UNKNOWN) {
--
2.25.1


2022-01-11 09:53:35

by Amjad Ouled-Ameur

[permalink] [raw]
Subject: [PATCH v6 3/3] phy: amlogic: meson8b-usb2: fix shared reset control use

Use reset_control_rearm() call if an error occurs in case
phy_meson8b_usb2_power_on() fails after reset() has been called, or in
case phy_meson8b_usb2_power_off() is called i.e the resource is no longer
used and the reset line may be triggered again by other devices.

reset_control_rearm() keeps use of triggered_count sane in the reset
framework, use of reset_control_reset() on shared reset line should
be balanced with reset_control_rearm().

Signed-off-by: Amjad Ouled-Ameur <[email protected]>
Reported-by: Jerome Brunet <[email protected]>
Reviewed-by: Martin Blumenstingl <[email protected]>
Acked-by: Neil Armstrong <[email protected]>
---
drivers/phy/amlogic/phy-meson8b-usb2.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/phy/amlogic/phy-meson8b-usb2.c b/drivers/phy/amlogic/phy-meson8b-usb2.c
index 77e7e9b1428c..dd96763911b8 100644
--- a/drivers/phy/amlogic/phy-meson8b-usb2.c
+++ b/drivers/phy/amlogic/phy-meson8b-usb2.c
@@ -154,6 +154,7 @@ static int phy_meson8b_usb2_power_on(struct phy *phy)
ret = clk_prepare_enable(priv->clk_usb_general);
if (ret) {
dev_err(&phy->dev, "Failed to enable USB general clock\n");
+ reset_control_rearm(priv->reset);
return ret;
}

@@ -161,6 +162,7 @@ static int phy_meson8b_usb2_power_on(struct phy *phy)
if (ret) {
dev_err(&phy->dev, "Failed to enable USB DDR clock\n");
clk_disable_unprepare(priv->clk_usb_general);
+ reset_control_rearm(priv->reset);
return ret;
}

@@ -199,6 +201,7 @@ static int phy_meson8b_usb2_power_on(struct phy *phy)
dev_warn(&phy->dev, "USB ID detect failed!\n");
clk_disable_unprepare(priv->clk_usb);
clk_disable_unprepare(priv->clk_usb_general);
+ reset_control_rearm(priv->reset);
return -EINVAL;
}
}
@@ -218,6 +221,7 @@ static int phy_meson8b_usb2_power_off(struct phy *phy)

clk_disable_unprepare(priv->clk_usb);
clk_disable_unprepare(priv->clk_usb_general);
+ reset_control_rearm(priv->reset);

/* power off the PHY by putting it into reset mode */
regmap_update_bits(priv->regmap, REG_CTRL, REG_CTRL_POWER_ON_RESET,
--
2.25.1


2022-01-27 12:12:24

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH v6 0/3] phy: amlogic: fix shared reset control use

On 11-01-22, 10:52, Amjad Ouled-Ameur wrote:
> This patchset fixes a usb suspend warning seen on the libretech-cc by
> using reset_control_rearm() call of the reset framework API.
> This call allows a reset consummer to release the reset line even when
> just triggered so that it may be triggered again by other reset
> consummers.
>
> reset_control_(de)assert() calls are called, in some meson usb drivers,
> on a shared reset line when reset_control_reset has been used. This is not
> allowed by the reset framework.
>
> Finally the meson usb drivers are updated to use this new call, which
> solves the suspend issue addressed by the previous reverted
> commit 7a410953d1fb ("usb: dwc3: meson-g12a: fix shared reset control
> use").

Applied, thanks

--
~Vinod