diff mbox series

[v4,1/3] phy: amlogic: phy-meson-gxl-usb2: fix shared reset controller use

Message ID 20211205215846.153703-2-aouledameur@baylibre.com (mailing list archive)
State Superseded
Headers show
Series usb: meson: fix shared reset control use | expand

Commit Message

Amjad Ouled-Ameur Dec. 5, 2021, 9:58 p.m. UTC
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 <aouledameur@baylibre.com>
Reported-by: Jerome Brunet <jbrunet@baylibre.com>
---
changes since v3:
- Remove unnecessary reset_control_rearm() after reset_control_reset()
failure.

 drivers/phy/amlogic/phy-meson-gxl-usb2.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Martin Blumenstingl Dec. 6, 2021, 9:19 p.m. UTC | #1
Hi Amjad,

On Sun, Dec 5, 2021 at 10:59 PM Amjad Ouled-Ameur
<aouledameur@baylibre.com> wrote:
>
> 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 <aouledameur@baylibre.com>
> Reported-by: Jerome Brunet <jbrunet@baylibre.com>
> ---
> changes since v3:
> - Remove unnecessary reset_control_rearm() after reset_control_reset()
> failure.
I double-checked your patch in v3 and Philipp was right:
reset_control_rearm() should not be right after reset_control_reset().
However, I think reset_control_rearm() is still needed
phy_meson_gxl_usb2_init() whenever clk_prepare_enable() fails.

So my suggestion is to add reset_control_rearm() in
phy_meson_gxl_usb2_init() if clk_prepare_enable() fails so we are
resetting the ref-count for the reset line (just like
phy_meson_gxl_usb2_exit() does).
The difference compared to the previous version is that the
reset_control_rearm() call needs to be placed a few lines down.


Thank you!
Martin
Amjad Ouled-Ameur Dec. 7, 2021, 11:20 a.m. UTC | #2
Hi Martin,

Thank you for the thorough review.


On 06/12/2021 22:19, Martin Blumenstingl wrote:
> Hi Amjad,
>
> On Sun, Dec 5, 2021 at 10:59 PM Amjad Ouled-Ameur
> <aouledameur@baylibre.com> wrote:
>> 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 <aouledameur@baylibre.com>
>> Reported-by: Jerome Brunet <jbrunet@baylibre.com>
>> ---
>> changes since v3:
>> - Remove unnecessary reset_control_rearm() after reset_control_reset()
>> failure.
> I double-checked your patch in v3 and Philipp was right:
> reset_control_rearm() should not be right after reset_control_reset().
> However, I think reset_control_rearm() is still needed
> phy_meson_gxl_usb2_init() whenever clk_prepare_enable() fails.

Well seen, reset_control_rearm() should actually be called after

clk_prepare_enable() fails. I will wait for any other potential reviews

before sending next version with this change you suggested.


Thank you Martin.

Amjad

> So my suggestion is to add reset_control_rearm() in
> phy_meson_gxl_usb2_init() if clk_prepare_enable() fails so we are
> resetting the ref-count for the reset line (just like
> phy_meson_gxl_usb2_exit() does).
> The difference compared to the previous version is that the
> reset_control_rearm() call needs to be placed a few lines down.
>
>
> Thank you!
> Martin
diff mbox series

Patch

diff --git a/drivers/phy/amlogic/phy-meson-gxl-usb2.c b/drivers/phy/amlogic/phy-meson-gxl-usb2.c
index 2b3c0d730f20..d2f56075dc57 100644
--- a/drivers/phy/amlogic/phy-meson-gxl-usb2.c
+++ b/drivers/phy/amlogic/phy-meson-gxl-usb2.c
@@ -125,6 +125,7 @@  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;
 }