On Mon, 27 Jan 2020, Yoshihiro Shimoda wrote: > Since EHCI/OHCI controllers on R-Car Gen3 SoCs are possible to > be getting stuck very rarely after a full/low usb device was > disconnected. To detect/recover from such a situation, the controllers > require a special way which poll the EHCI PORTSC register and changes > the OHCI functional state. > > So, this patch adds a polling timer into the ehci-platform driver, > and if the ehci driver detects the issue by the EHCI PORTSC register, > the ehci driver removes a companion device (= the OHCI controller) > to change the OHCI functional state to USB Reset once. And then, > the ehci driver adds the companion device again. > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > --- > Changes from v3: > - Fix the comment of PORT_LS_MASK. > - Remove a comment about the bit 11:10 of PORTSC register. > https://patchwork.kernel.org/patch/11349733/ > > Changes from v2: > - Use .family instead of .soc_id members on quirk_poll_match. > https://patchwork.kernel.org/patch/11347521/ > > Changes from v1: > - Remove adding a new property into the generic-ehci.yaml. > - Add kerneldoc sections. > - Remove prefix "ehci_platform_" from function names. > - Rename quirk_poll_check_condition() with quirk_poll_check_port_status(). > - Fix some coding style. > - Remove "start_timer" function and use HZ on mod_timer(). > - Use delayed_work instead of usleep_range(). > https://patchwork.kernel.org/project/linux-renesas-soc/list/?series=229861 > > drivers/usb/host/ehci-platform.c | 127 +++++++++++++++++++++++++++++++++++++++ > include/linux/usb/ehci_def.h | 2 +- > 2 files changed, 128 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-platform.c > index 769749c..e4fc3f6 100644 > --- a/drivers/usb/host/ehci-platform.c > +++ b/drivers/usb/host/ehci-platform.c > @@ -29,6 +29,8 @@ > #include <linux/of.h> > #include <linux/platform_device.h> > #include <linux/reset.h> > +#include <linux/sys_soc.h> > +#include <linux/timer.h> > #include <linux/usb.h> > #include <linux/usb/hcd.h> > #include <linux/usb/ehci_pdriver.h> > @@ -44,6 +46,9 @@ struct ehci_platform_priv { > struct clk *clks[EHCI_MAX_CLKS]; > struct reset_control *rsts; > bool reset_on_resume; > + bool quirk_poll; > + struct timer_list poll_timer; > + struct delayed_work poll_work; > }; > > static const char hcd_name[] = "ehci-platform"; > @@ -118,6 +123,111 @@ static struct usb_ehci_pdata ehci_platform_defaults = { > .power_off = ehci_platform_power_off, > }; > > +/** > + * quirk_poll_check_port_status - Poll port_status if the device sticks > + * @ehci: the ehci hcd pointer > + * > + * Since EHCI/OHCI controllers on R-Car Gen3 SoCs are possible to be getting > + * stuck very rarely after a full/low usb device was disconnected. To > + * detect such a situation, the controllers require a special way which poll > + * the EHCI PORTSC register. > + * > + * Return: true if the controller's port_status indicated getting stuck > + */ > +static bool quirk_poll_check_port_status(struct ehci_hcd *ehci) > +{ > + u32 port_status = ehci_readl(ehci, &ehci->regs->port_status[0]); > + > + if (!(port_status & PORT_OWNER) && > + (port_status & PORT_POWER) && > + !(port_status & PORT_CONNECT) && > + (port_status & PORT_LS_MASK)) > + return true; > + > + return false; > +} > + > +/** > + * quirk_poll_rebind_companion - rebind comanion device to recover > + * @ehci: the ehci hcd pointer > + * > + * Since EHCI/OHCI controllers on R-Car Gen3 SoCs are possible to be getting > + * stuck very rarely after a full/low usb device was disconnected. To > + * recover from such a situation, the controllers require changing the OHCI > + * functional state. > + */ > +static void quirk_poll_rebind_companion(struct ehci_hcd *ehci) > +{ > + struct device *companion_dev; > + struct usb_hcd *hcd = ehci_to_hcd(ehci); > + > + companion_dev = usb_of_get_companion_dev(hcd->self.controller); > + if (!companion_dev) > + return; > + > + device_release_driver(companion_dev); > + if (device_attach(companion_dev) < 0) > + ehci_err(ehci, "%s: failed\n", __func__); > + > + put_device(companion_dev); > +} > + > +static void quirk_poll_work(struct work_struct *work) > +{ > + struct ehci_platform_priv *priv = > + container_of(to_delayed_work(work), struct ehci_platform_priv, > + poll_work); > + struct ehci_hcd *ehci = container_of((void *)priv, struct ehci_hcd, > + priv); > + > + /* check the status twice to reduce misdetection rate */ > + if (!quirk_poll_check_port_status(ehci)) > + return; > + udelay(10); > + if (!quirk_poll_check_port_status(ehci)) > + return; > + > + ehci_dbg(ehci, "%s: detected getting stuck. rebind now!\n", __func__); > + quirk_poll_rebind_companion(ehci); > +} > + > +static void quirk_poll_timer(struct timer_list *t) > +{ > + struct ehci_platform_priv *priv = from_timer(priv, t, poll_timer); > + struct ehci_hcd *ehci = container_of((void *)priv, struct ehci_hcd, > + priv); > + > + if (quirk_poll_check_port_status(ehci)) { > + /* > + * Now scheduling the work for testing the port more. Note that > + * updating the status is possible to be delayed when > + * reconnection. So, this uses delayed work with 5 ms delay > + * to avoid misdetection. > + */ > + schedule_delayed_work(&priv->poll_work, msecs_to_jiffies(5)); > + } > + > + mod_timer(&priv->poll_timer, jiffies + HZ); > +} > + > +static void quirk_poll_init(struct ehci_platform_priv *priv) > +{ > + INIT_DELAYED_WORK(&priv->poll_work, quirk_poll_work); > + timer_setup(&priv->poll_timer, quirk_poll_timer, 0); > + mod_timer(&priv->poll_timer, jiffies + HZ); > +} > + > +static void quirk_poll_end(struct ehci_platform_priv *priv) > +{ > + del_timer_sync(&priv->poll_timer); > + cancel_delayed_work(&priv->poll_work); > +} > + > +static const struct soc_device_attribute quirk_poll_match[] = { > + { .family = "R-Car Gen3" }, > + { /* sentinel*/ } > +}; > + > static int ehci_platform_probe(struct platform_device *dev) > { > struct usb_hcd *hcd; > @@ -176,6 +286,9 @@ static int ehci_platform_probe(struct platform_device *dev) > "has-transaction-translator")) > hcd->has_tt = 1; > > + if (soc_device_match(quirk_poll_match)) > + priv->quirk_poll = true; > + > for (clk = 0; clk < EHCI_MAX_CLKS; clk++) { > priv->clks[clk] = of_clk_get(dev->dev.of_node, clk); > if (IS_ERR(priv->clks[clk])) { > @@ -247,6 +360,9 @@ static int ehci_platform_probe(struct platform_device *dev) > device_enable_async_suspend(hcd->self.controller); > platform_set_drvdata(dev, hcd); > > + if (priv->quirk_poll) > + quirk_poll_init(priv); > + > return err; > > err_power: > @@ -273,6 +389,9 @@ static int ehci_platform_remove(struct platform_device *dev) > struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd); > int clk; > > + if (priv->quirk_poll) > + quirk_poll_end(priv); > + > usb_remove_hcd(hcd); > > if (pdata->power_off) > @@ -297,9 +416,13 @@ static int ehci_platform_suspend(struct device *dev) > struct usb_hcd *hcd = dev_get_drvdata(dev); > struct usb_ehci_pdata *pdata = dev_get_platdata(dev); > struct platform_device *pdev = to_platform_device(dev); > + struct ehci_platform_priv *priv = hcd_to_ehci_priv(hcd); > bool do_wakeup = device_may_wakeup(dev); > int ret; > > + if (priv->quirk_poll) > + quirk_poll_end(priv); > + > ret = ehci_suspend(hcd, do_wakeup); > if (ret) > return ret; > @@ -331,6 +454,10 @@ static int ehci_platform_resume(struct device *dev) > } > > ehci_resume(hcd, priv->reset_on_resume); > + > + if (priv->quirk_poll) > + quirk_poll_init(priv); > + > return 0; > } > #endif /* CONFIG_PM_SLEEP */ > diff --git a/include/linux/usb/ehci_def.h b/include/linux/usb/ehci_def.h > index a15ce99..78e0063 100644 > --- a/include/linux/usb/ehci_def.h > +++ b/include/linux/usb/ehci_def.h > @@ -151,7 +151,7 @@ struct ehci_regs { > #define PORT_OWNER (1<<13) /* true: companion hc owns this port */ > #define PORT_POWER (1<<12) /* true: has power (see PPC) */ > #define PORT_USB11(x) (((x)&(3<<10)) == (1<<10)) /* USB 1.1 device */ > -/* 11:10 for detecting lowspeed devices (reset vs release ownership) */ > +#define PORT_LS_MASK (3<<10) /* Link status (SE0, K or J */ > /* 9 reserved */ > #define PORT_LPM (1<<9) /* LPM transaction */ > #define PORT_RESET (1<<8) /* reset port */ >
