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> --- 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 */ -- 2.7.4
