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Message-Id: <20200623195351.423914561@linuxfoundation.org>
Date: Tue, 23 Jun 2020 21:57:36 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>,
Alan Stern <stern@...land.harvard.edu>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.4 261/314] usb: host: ehci-platform: add a quirk to avoid stuck
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>
[ Upstream commit cc7eac1e4afdd151085be4d0341a155760388653 ]
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@...esas.com>
Acked-by: Alan Stern <stern@...land.harvard.edu>
Link: https://lore.kernel.org/r/1580114262-25029-1-git-send-email-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
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 769749ca5961a..e4fc3f66d43bf 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 a15ce99dfc2d6..78e0063555575 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 */
--
2.25.1
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