[PATCH] phy: allwinner: sun4i-usb: disable the PHY2 PMU clock after SIDDQ setup

[PATCH] phy: allwinner: sun4i-usb: disable the PHY2 PMU clock after SIDDQ setup

[raoxu]

From: Xu Rao <raoxu@uniontech.com>

sun4i_usb_phy_init() temporarily enables PHY2's clk2 when a SoC needs
PHY2 SIDDQ setup while initializing another PHY. However, after updating
PHY2's PMU register it disables the clk2 pointer from the PHY currently
being initialized.

This leaves PHY2's clk2 enabled and also drops an extra reference from
the current PHY's clk2, causing the prepare/enable accounting to become
unbalanced.

Disable the same PHY2 clk2 that was enabled for the auxiliary PMU access.

Signed-off-by: Xu Rao <raoxu@uniontech.com>
---
 drivers/phy/allwinner/phy-sun4i-usb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c
index e2fbf8ccf99e..839856c09e30 100644
--- a/drivers/phy/allwinner/phy-sun4i-usb.c
+++ b/drivers/phy/allwinner/phy-sun4i-usb.c
@@ -318,7 +318,7 @@ static int sun4i_usb_phy_init(struct phy *_phy)
 			writel(val, phy2->pmu + REG_HCI_PHY_CTL);
 		}

-		clk_disable_unprepare(phy->clk2);
+		clk_disable_unprepare(phy2->clk2);
 	}

 	if (phy->pmu && data->cfg->hci_phy_ctl_clear) {
--
2.50.1

Re: [PATCH] phy: allwinner: sun4i-usb: disable the PHY2 PMU clock after SIDDQ setup

[Andre Przywara]

Hi,

On 7/6/26 11:35, raoxu wrote:
> From: Xu Rao <raoxu@uniontech.com>
> 
> sun4i_usb_phy_init() temporarily enables PHY2's clk2 when a SoC needs
> PHY2 SIDDQ setup while initializing another PHY. However, after updating
> PHY2's PMU register it disables the clk2 pointer from the PHY currently
> being initialized.
> 
> This leaves PHY2's clk2 enabled and also drops an extra reference from
> the current PHY's clk2, causing the prepare/enable accounting to become
> unbalanced.
> 
> Disable the same PHY2 clk2 that was enabled for the auxiliary PMU access.
> 
> Signed-off-by: Xu Rao <raoxu@uniontech.com>
> ---
>   drivers/phy/allwinner/phy-sun4i-usb.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c
> index e2fbf8ccf99e..839856c09e30 100644
> --- a/drivers/phy/allwinner/phy-sun4i-usb.c
> +++ b/drivers/phy/allwinner/phy-sun4i-usb.c
> @@ -318,7 +318,7 @@ static int sun4i_usb_phy_init(struct phy *_phy)
>   			writel(val, phy2->pmu + REG_HCI_PHY_CTL);
>   		}
> 
> -		clk_disable_unprepare(phy->clk2);
> +		clk_disable_unprepare(phy2->clk2);

Interesting, this looks about right, and matches the comment above, 
noting that phy2->clk2 is just temporarily needed. I don't remember 
further details, only that this workaround was quite annoying and messy ;-)

However I am wondering how this worked so far: This should sabotage the 
access to the local REG_HCI_PHY_CTL access in the next few lines ...
Any idea why this worked nevertheless?

Thanks,
Andre

>   	}
> 
>   	if (phy->pmu && data->cfg->hci_phy_ctl_clear) {
> --
> 2.50.1
>