From mboxrd@z Thu Jan 1 00:00:00 1970 From: Icenowy Zheng Date: Wed, 07 Apr 2021 14:43:56 +0800 Subject: [PATCH] phy: rockchip: inno-usb2: fix hang when multiple controllers exit In-Reply-To: <4e48a1c9-fd01-48c8-fc5d-ebdfb626ee42@rock-chips.com> References: <20210406151059.1187379-1-icenowy@aosc.io> <4e48a1c9-fd01-48c8-fc5d-ebdfb626ee42@rock-chips.com> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de ? 2021?4?7? GMT+08:00 ??2:42:34, Frank Wang ??: >Hi Icenowy Zheng, > >In my view, it is better to implement this mechanism in phy-uclass >which >resemble Linux Kernel have implemented that can avoid do duplication of > >work in each SoC's PHY driver. I'm afraid of breaking existing drivers when implementing it in uclass, although I agree this will be more clean. > > >BR. >Frank > >On 2021/4/6 23:10, Icenowy Zheng wrote: >> The OHCI and EHCI controllers are both bound to the same PHY. They >will >> both do init and power_on operations when the controller is brought >up >> and both do power_off and exit when the controller is stopped. >However, >> the PHY uclass of U-Boot is not as sane as we thought -- they won't >> maintain a status mark for PHYs, and thus the functions of the PHYs >> could be called for multiple times. Calling init/power_on for >multiple >> times have no severe problems, however calling power_off/exit for >> multiple times have a problem -- the first exit call will stop the >PHY >> clock, and power_off/exit calls after it still trying to write to PHY >> registers. The write operation to PHY registers will fail because >clock >> is already stopped. >> >> Adapt the count mechanism from phy-sun4i-usb to both init/exit and >> power_on/power_off functions to phy-rockchip-inno-usb2 to fix this >> problem. With this stopping USB controllers (manually or before >booting >> a kernel) will work. >> >> Signed-off-by: Icenowy Zheng >> Fixes: ac97a9ece14e ("phy: rockchip: Add Rockchip USB2PHY driver") >> --- >> drivers/phy/rockchip/phy-rockchip-inno-usb2.c | 21 >+++++++++++++++++++ >> 1 file changed, 21 insertions(+) >> >> diff --git a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c >b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c >> index 62b8ba3a4a..be9cc99d90 100644 >> --- a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c >> +++ b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c >> @@ -62,6 +62,8 @@ struct rockchip_usb2phy { >> void *reg_base; >> struct clk phyclk; >> const struct rockchip_usb2phy_cfg *phy_cfg; >> + int init_count; >> + int power_on_count; >> }; >> >> static inline int property_enable(void *reg_base, >> @@ -92,6 +94,10 @@ static int rockchip_usb2phy_power_on(struct phy >*phy) >> struct rockchip_usb2phy *priv = dev_get_priv(parent); >> const struct rockchip_usb2phy_port_cfg *port_cfg = >us2phy_get_port(phy); >> >> + priv->power_on_count++; >> + if (priv->power_on_count != 1) >> + return 0; >> + >> property_enable(priv->reg_base, &port_cfg->phy_sus, false); >> >> /* waiting for the utmi_clk to become stable */ >> @@ -106,6 +112,10 @@ static int rockchip_usb2phy_power_off(struct phy >*phy) >> struct rockchip_usb2phy *priv = dev_get_priv(parent); >> const struct rockchip_usb2phy_port_cfg *port_cfg = >us2phy_get_port(phy); >> >> + priv->power_on_count--; >> + if (priv->power_on_count != 0) >> + return 0; >> + >> property_enable(priv->reg_base, &port_cfg->phy_sus, true); >> >> return 0; >> @@ -118,6 +128,10 @@ static int rockchip_usb2phy_init(struct phy >*phy) >> const struct rockchip_usb2phy_port_cfg *port_cfg = >us2phy_get_port(phy); >> int ret; >> >> + priv->init_count++; >> + if (priv->init_count != 1) >> + return 0; >> + >> ret = clk_enable(&priv->phyclk); >> if (ret) { >> dev_err(phy->dev, "failed to enable phyclk (ret=%d)\n", ret); >> @@ -140,6 +154,10 @@ static int rockchip_usb2phy_exit(struct phy >*phy) >> struct udevice *parent = dev_get_parent(phy->dev); >> struct rockchip_usb2phy *priv = dev_get_priv(parent); >> >> + priv->init_count--; >> + if (priv->init_count != 0) >> + return 0; >> + >> clk_disable(&priv->phyclk); >> >> return 0; >> @@ -212,6 +230,9 @@ static int rockchip_usb2phy_probe(struct udevice >*dev) >> return ret; >> } >> >> + priv->power_on_count = 0; >> + priv->init_count = 0; >> + >> return 0; >> } >>