[PATCH 00/10] xhci features for usb-next

[PATCH 00/10] xhci features for usb-next

[Mathias Nyman]

Hi Greg

A few minor xhci improvements for usb-next
-Mathias 

Li Jun (1):
  usb: xhci: add debugfs support for ep with stream

Mathias Nyman (2):
  xhci: Tune interrupt blocking for isochronous transfers
  xhci: don't create endpoint debugfs entry before ring buffer is set.

Peter Chen (7):
  usb: host: xhci-plat: add platform data support
  usb: host: xhci-plat: add .suspend_quirk for struct xhci_plat_priv
  usb: host: xhci-plat: delete the unnecessary code
  usb: host: xhci-plat: add priv quirk for skip PHY initialization
  usb: host: xhci-plat: add wakeup entry at sysfs
  usb: host: xhci-plat: improve the comments for xhci_plat_suspend
  usb: xhci: omit duplicate actions when suspending a runtime suspended
    host.

 drivers/usb/host/xhci-debugfs.c | 109 +++++++++++++++++++++++++++++++-
 drivers/usb/host/xhci-debugfs.h |  10 +++
 drivers/usb/host/xhci-plat.c    |  44 +++++++++----
 drivers/usb/host/xhci-plat.h    |   1 +
 drivers/usb/host/xhci-ring.c    |  23 +++++--
 drivers/usb/host/xhci.c         |  11 ++--
 drivers/usb/host/xhci.h         |   1 +
 7 files changed, 179 insertions(+), 20 deletions(-)

-- 
2.17.1

[PATCH 01/10] usb: host: xhci-plat: add platform data support

[Mathias Nyman]

From: Peter Chen <peter.chen@nxp.com>

Some xhci hosts (eg dwc3 and cdns3) do not use OF to create
platform device, they create xhci-plat platform device runtime.
And these platforms may also have quirks, and the quirks could
be supplied by their parent device through platform data.

Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-plat.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 3057cfc76d6a..c7f98edc5678 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -264,7 +264,11 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	if (ret)
 		goto disable_reg_clk;
 
-	priv_match = of_device_get_match_data(&pdev->dev);
+	if (pdev->dev.of_node)
+		priv_match = of_device_get_match_data(&pdev->dev);
+	else
+		priv_match = dev_get_platdata(&pdev->dev);
+
 	if (priv_match) {
 		struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
 
-- 
2.17.1

[PATCH 02/10] usb: host: xhci-plat: add .suspend_quirk for struct xhci_plat_priv

[Mathias Nyman]

From: Peter Chen <peter.chen@nxp.com>

Some platforms (eg cdns3) may have special sequences between
xhci_bus_suspend and xhci_suspend, add .suspend_quick for it.

Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-plat.c | 19 +++++++++++++++++++
 drivers/usb/host/xhci-plat.h |  1 +
 2 files changed, 20 insertions(+)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index c7f98edc5678..c3ce4d762adf 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -54,6 +54,16 @@ static int xhci_priv_init_quirk(struct usb_hcd *hcd)
 	return priv->init_quirk(hcd);
 }
 
+static int xhci_priv_suspend_quirk(struct usb_hcd *hcd)
+{
+	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
+
+	if (!priv->suspend_quirk)
+		return 0;
+
+	return priv->suspend_quirk(hcd);
+}
+
 static int xhci_priv_resume_quirk(struct usb_hcd *hcd)
 {
 	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
@@ -401,7 +411,11 @@ static int __maybe_unused xhci_plat_suspend(struct device *dev)
 {
 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
+	int ret;
 
+	ret = xhci_priv_suspend_quirk(hcd);
+	if (ret)
+		return ret;
 	/*
 	 * xhci_suspend() needs `do_wakeup` to know whether host is allowed
 	 * to do wakeup during suspend. Since xhci_plat_suspend is currently
@@ -438,6 +452,11 @@ static int __maybe_unused xhci_plat_runtime_suspend(struct device *dev)
 {
 	struct usb_hcd  *hcd = dev_get_drvdata(dev);
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	int ret;
+
+	ret = xhci_priv_suspend_quirk(hcd);
+	if (ret)
+		return ret;
 
 	return xhci_suspend(xhci, true);
 }
diff --git a/drivers/usb/host/xhci-plat.h b/drivers/usb/host/xhci-plat.h
index b49f6447bd3a..1fb149d1fbce 100644
--- a/drivers/usb/host/xhci-plat.h
+++ b/drivers/usb/host/xhci-plat.h
@@ -15,6 +15,7 @@ struct xhci_plat_priv {
 	unsigned long long quirks;
 	void (*plat_start)(struct usb_hcd *);
 	int (*init_quirk)(struct usb_hcd *);
+	int (*suspend_quirk)(struct usb_hcd *);
 	int (*resume_quirk)(struct usb_hcd *);
 };
 
-- 
2.17.1

[PATCH 03/10] usb: host: xhci-plat: delete the unnecessary code

[Mathias Nyman]

From: Peter Chen <peter.chen@nxp.com>

The if {} condition is duplicated with outer if {} condition.

Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-plat.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index c3ce4d762adf..07ca000a0084 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -283,8 +283,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
 		struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
 
 		/* Just copy data for now */
-		if (priv_match)
-			*priv = *priv_match;
+		*priv = *priv_match;
 	}
 
 	device_wakeup_enable(hcd->self.controller);
-- 
2.17.1

[PATCH 04/10] usb: host: xhci-plat: add priv quirk for skip PHY initialization

[Mathias Nyman]

From: Peter Chen <peter.chen@nxp.com>

Some DRD controllers (eg, dwc3 & cdns3) have PHY management at
their own driver to cover both device and host mode, so add one
priv quirk for such users to skip PHY management from HCD core.

Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-plat.c | 8 ++++++--
 drivers/usb/host/xhci.h      | 1 +
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 07ca000a0084..14ff65a387e8 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -183,6 +183,8 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	struct usb_hcd		*hcd;
 	int			ret;
 	int			irq;
+	struct xhci_plat_priv	*priv = NULL;
+
 
 	if (usb_disabled())
 		return -ENODEV;
@@ -280,8 +282,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
 		priv_match = dev_get_platdata(&pdev->dev);
 
 	if (priv_match) {
-		struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
-
+		priv = hcd_to_xhci_priv(hcd);
 		/* Just copy data for now */
 		*priv = *priv_match;
 	}
@@ -329,6 +330,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
 
 	hcd->tpl_support = of_usb_host_tpl_support(sysdev->of_node);
 	xhci->shared_hcd->tpl_support = hcd->tpl_support;
+	if (priv && (priv->quirks & XHCI_SKIP_PHY_INIT))
+		hcd->skip_phy_initialization = 1;
+
 	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (ret)
 		goto disable_usb_phy;
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index ea1754f185a2..7658abdfca28 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1874,6 +1874,7 @@ struct xhci_hcd {
 #define XHCI_RESET_PLL_ON_DISCONNECT	BIT_ULL(34)
 #define XHCI_SNPS_BROKEN_SUSPEND    BIT_ULL(35)
 #define XHCI_RENESAS_FW_QUIRK	BIT_ULL(36)
+#define XHCI_SKIP_PHY_INIT	BIT_ULL(37)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
-- 
2.17.1

[PATCH 05/10] usb: host: xhci-plat: add wakeup entry at sysfs

[Mathias Nyman]

From: Peter Chen <peter.chen@nxp.com>

With this change, there will be a wakeup entry at /sys/../power/wakeup,
and the user could use this entry to choose whether enable xhci wakeup
features (wake up system from suspend) or not.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-plat.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 14ff65a387e8..cfca6fc8947c 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -287,7 +287,7 @@ static int xhci_plat_probe(struct platform_device *pdev)
 		*priv = *priv_match;
 	}
 
-	device_wakeup_enable(hcd->self.controller);
+	device_set_wakeup_capable(&pdev->dev, true);
 
 	xhci->main_hcd = hcd;
 	xhci->shared_hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
-- 
2.17.1

[PATCH 06/10] usb: host: xhci-plat: improve the comments for xhci_plat_suspend

[Mathias Nyman]

From: Peter Chen <peter.chen@nxp.com>

To reflect the current code status.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-plat.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index cfca6fc8947c..aa2d35f98200 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -421,11 +421,7 @@ static int __maybe_unused xhci_plat_suspend(struct device *dev)
 		return ret;
 	/*
 	 * xhci_suspend() needs `do_wakeup` to know whether host is allowed
-	 * to do wakeup during suspend. Since xhci_plat_suspend is currently
-	 * only designed for system suspend, device_may_wakeup() is enough
-	 * to dertermine whether host is allowed to do wakeup. Need to
-	 * reconsider this when xhci_plat_suspend enlarges its scope, e.g.,
-	 * also applies to runtime suspend.
+	 * to do wakeup during suspend.
 	 */
 	return xhci_suspend(xhci, device_may_wakeup(dev));
 }
-- 
2.17.1

[PATCH 07/10] usb: xhci: omit duplicate actions when suspending a runtime suspended host.

[Mathias Nyman]

From: Peter Chen <peter.chen@nxp.com>

If the xhci-plat.c is the platform driver, after the runtime pm is
enabled, the xhci_suspend is called if nothing is connected on
the port. When the system goes to suspend, it will call xhci_suspend again
if USB wakeup is enabled.

Since the runtime suspend wakeup setting is not always the same as
system suspend wakeup setting, eg, at runtime suspend we always need
wakeup if the controller is in low power mode; but at system suspend,
we may not need wakeup. So, we move the judgement after changing
wakeup setting.

[commit message rewording -Mathias]
Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f4cedcaee14b..4cfb95104c26 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -982,12 +982,15 @@ int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup)
 			xhci->shared_hcd->state != HC_STATE_SUSPENDED)
 		return -EINVAL;
 
-	xhci_dbc_suspend(xhci);
-
 	/* Clear root port wake on bits if wakeup not allowed. */
 	if (!do_wakeup)
 		xhci_disable_port_wake_on_bits(xhci);
 
+	if (!HCD_HW_ACCESSIBLE(hcd))
+		return 0;
+
+	xhci_dbc_suspend(xhci);
+
 	/* Don't poll the roothubs on bus suspend. */
 	xhci_dbg(xhci, "%s: stopping port polling.\n", __func__);
 	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
-- 
2.17.1

[PATCH 08/10] xhci: Tune interrupt blocking for isochronous transfers

[Mathias Nyman]

controllers with XHCI_AVOID_BEI quirk cause too frequent interrupts
and affect power management.

To avoid interrupting on every isochronous interval the BEI (Block
Event Interrupt) flag is set for all except the last Isoch TRB in a URB.
This lead to event ring filling up in case several isoc URB were
queued and cancelled rapidly, which some controllers didn't
handle well, and thus the XHCI_AVOID_BEI quirk was introduced.
see commit 227a4fd801c8 ("usb: xhci: apply XHCI_AVOID_BEI quirk to all
Intel xHCI controllers")

With the XHCI_AVOID_BEI quirk each Isoch TRB will trigger an interrupt.
This can cause up to 8000 interrupts per second for isochronous transfers
with HD USB3 cameras, affecting power saving.

The event ring fits 256 events, instead of interrupting on every
isochronous TRB if XHCI_AVOID_BEI is set we make sure at least every
8th Isochronous TRB asserts an interrupt, clearing the event ring.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-ring.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index a741a38a4c69..167dae117f73 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -3736,6 +3736,24 @@ static int xhci_get_isoc_frame_id(struct xhci_hcd *xhci,
 	return start_frame;
 }
 
+/* Check if we should generate event interrupt for a TD in an isoc URB */
+static bool trb_block_event_intr(struct xhci_hcd *xhci, int num_tds, int i)
+{
+	if (xhci->hci_version < 0x100)
+		return false;
+	/* always generate an event interrupt for the last TD */
+	if (i == num_tds - 1)
+		return false;
+	/*
+	 * If AVOID_BEI is set the host handles full event rings poorly,
+	 * generate an event at least every 8th TD to clear the event ring
+	 */
+	if (i && xhci->quirks & XHCI_AVOID_BEI)
+		return !!(i % 8);
+
+	return true;
+}
+
 /* This is for isoc transfer */
 static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 		struct urb *urb, int slot_id, unsigned int ep_index)
@@ -3843,10 +3861,7 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 				more_trbs_coming = false;
 				td->last_trb = ep_ring->enqueue;
 				field |= TRB_IOC;
-				/* set BEI, except for the last TD */
-				if (xhci->hci_version >= 0x100 &&
-				    !(xhci->quirks & XHCI_AVOID_BEI) &&
-				    i < num_tds - 1)
+				if (trb_block_event_intr(xhci, num_tds, i))
 					field |= TRB_BEI;
 			}
 			/* Calculate TRB length */
-- 
2.17.1

[PATCH 09/10] xhci: don't create endpoint debugfs entry before ring buffer is set.

[Mathias Nyman]

Make sure xHC completes the configure endpoint command and xhci driver
sets the ring pointers correctly before we create the user readable
debugfs file.

In theory there was a small gap where a user could have read the
debugfs file and cause a NULL pointer dereference error as ring
pointer was not yet set, in practise we want this change to simplify
the upcoming streams debugfs support.

Fixes: 02b6fdc2a153 ("usb: xhci: Add debugfs interface for xHCI driver")
Cc: stable@vger.kernel.org #v4.19+
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 4cfb95104c26..e88f4f953995 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1918,8 +1918,6 @@ static int xhci_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
 	ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
 	trace_xhci_add_endpoint(ep_ctx);
 
-	xhci_debugfs_create_endpoint(xhci, virt_dev, ep_index);
-
 	xhci_dbg(xhci, "add ep 0x%x, slot id %d, new drop flags = %#x, new add flags = %#x\n",
 			(unsigned int) ep->desc.bEndpointAddress,
 			udev->slot_id,
@@ -2952,6 +2950,7 @@ static int xhci_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
 		xhci_check_bw_drop_ep_streams(xhci, virt_dev, i);
 		virt_dev->eps[i].ring = virt_dev->eps[i].new_ring;
 		virt_dev->eps[i].new_ring = NULL;
+		xhci_debugfs_create_endpoint(xhci, virt_dev, i);
 	}
 command_cleanup:
 	kfree(command->completion);
-- 
2.17.1

Re: [PATCH 09/10] xhci: don't create endpoint debugfs entry before ring buffer is set.

[Sasha Levin]

Hi

[This is an automated email]

This commit has been processed because it contains a "Fixes:" tag
fixing commit: 02b6fdc2a153 ("usb: xhci: Add debugfs interface for xHCI driver").

The bot has tested the following trees: v5.8.10, v5.4.66, v4.19.146.

v5.8.10: Build OK!
v5.4.66: Build OK!
v4.19.146: Failed to apply! Possible dependencies:
    5afa0a5ed3da ("usb: xhci: add endpoint context tracing when an endpoint is added")


NOTE: The patch will not be queued to stable trees until it is upstream.

How should we proceed with this patch?

-- 
Thanks
Sasha

[PATCH 10/10] usb: xhci: add debugfs support for ep with stream

[Mathias Nyman]

From: Li Jun <jun.li@nxp.com>

To show the trb ring of streams, use the exsiting ring files of bulk ep
to show trb ring of one specific stream ID, which stream ID's trb ring
will be shown, is controlled by a new debugfs file stream_id, this is to
avoid to create a large number of dir for every allocate stream IDs,
another debugfs file stream_context_array is created to show all the
allocated stream context array entries.

Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-debugfs.c | 109 +++++++++++++++++++++++++++++++-
 drivers/usb/host/xhci-debugfs.h |  10 +++
 drivers/usb/host/xhci.c         |   1 +
 3 files changed, 119 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-debugfs.c b/drivers/usb/host/xhci-debugfs.c
index c88bffd68742..2c0fda57869e 100644
--- a/drivers/usb/host/xhci-debugfs.c
+++ b/drivers/usb/host/xhci-debugfs.c
@@ -451,9 +451,11 @@ void xhci_debugfs_create_endpoint(struct xhci_hcd *xhci,
 	if (!epriv)
 		return;
 
+	epriv->show_ring = dev->eps[ep_index].ring;
+
 	snprintf(epriv->name, sizeof(epriv->name), "ep%02d", ep_index);
 	epriv->root = xhci_debugfs_create_ring_dir(xhci,
-						   &dev->eps[ep_index].ring,
+						   &epriv->show_ring,
 						   epriv->name,
 						   spriv->root);
 	spriv->eps[ep_index] = epriv;
@@ -475,6 +477,111 @@ void xhci_debugfs_remove_endpoint(struct xhci_hcd *xhci,
 	kfree(epriv);
 }
 
+static int xhci_stream_id_show(struct seq_file *s, void *unused)
+{
+	struct xhci_ep_priv	*epriv = s->private;
+
+	if (!epriv->stream_info)
+		return -EPERM;
+
+	seq_printf(s, "Show stream ID %d trb ring, supported [1 - %d]\n",
+		   epriv->stream_id, epriv->stream_info->num_streams - 1);
+
+	return 0;
+}
+
+static int xhci_stream_id_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, xhci_stream_id_show, inode->i_private);
+}
+
+static ssize_t xhci_stream_id_write(struct file *file,  const char __user *ubuf,
+			       size_t count, loff_t *ppos)
+{
+	struct seq_file         *s = file->private_data;
+	struct xhci_ep_priv	*epriv = s->private;
+	int			ret;
+	u16			stream_id; /* MaxPStreams + 1 <= 16 */
+
+	if (!epriv->stream_info)
+		return -EPERM;
+
+	/* Decimal number */
+	ret = kstrtou16_from_user(ubuf, count, 10, &stream_id);
+	if (ret)
+		return ret;
+
+	if (stream_id == 0 || stream_id >= epriv->stream_info->num_streams)
+		return -EINVAL;
+
+	epriv->stream_id = stream_id;
+	epriv->show_ring = epriv->stream_info->stream_rings[stream_id];
+
+	return count;
+}
+
+static const struct file_operations stream_id_fops = {
+	.open			= xhci_stream_id_open,
+	.write                  = xhci_stream_id_write,
+	.read			= seq_read,
+	.llseek			= seq_lseek,
+	.release		= single_release,
+};
+
+static int xhci_stream_context_array_show(struct seq_file *s, void *unused)
+{
+	struct xhci_ep_priv	*epriv = s->private;
+	struct xhci_stream_ctx	*stream_ctx;
+	dma_addr_t		dma;
+	int			id;
+
+	if (!epriv->stream_info)
+		return -EPERM;
+
+	seq_printf(s, "Allocated %d streams and %d stream context array entries\n",
+			epriv->stream_info->num_streams,
+			epriv->stream_info->num_stream_ctxs);
+
+	for (id = 0; id < epriv->stream_info->num_stream_ctxs; id++) {
+		stream_ctx = epriv->stream_info->stream_ctx_array + id;
+		dma = epriv->stream_info->ctx_array_dma + id * 16;
+		if (id < epriv->stream_info->num_streams)
+			seq_printf(s, "%pad stream id %d deq %016llx\n", &dma,
+				   id, le64_to_cpu(stream_ctx->stream_ring));
+		else
+			seq_printf(s, "%pad stream context entry not used deq %016llx\n",
+				   &dma, le64_to_cpu(stream_ctx->stream_ring));
+	}
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(xhci_stream_context_array);
+
+void xhci_debugfs_create_stream_files(struct xhci_hcd *xhci,
+				      struct xhci_virt_device *dev,
+				      int ep_index)
+{
+	struct xhci_slot_priv	*spriv = dev->debugfs_private;
+	struct xhci_ep_priv	*epriv;
+
+	if (!spriv || !spriv->eps[ep_index] ||
+	    !dev->eps[ep_index].stream_info)
+		return;
+
+	epriv = spriv->eps[ep_index];
+	epriv->stream_info = dev->eps[ep_index].stream_info;
+
+	/* Show trb ring of stream ID 1 by default */
+	epriv->stream_id = 1;
+	epriv->show_ring = epriv->stream_info->stream_rings[1];
+	debugfs_create_file("stream_id", 0644,
+			    epriv->root, epriv,
+			    &stream_id_fops);
+	debugfs_create_file("stream_context_array", 0444,
+			    epriv->root, epriv,
+			    &xhci_stream_context_array_fops);
+}
+
 void xhci_debugfs_create_slot(struct xhci_hcd *xhci, int slot_id)
 {
 	struct xhci_slot_priv	*priv;
diff --git a/drivers/usb/host/xhci-debugfs.h b/drivers/usb/host/xhci-debugfs.h
index 56db635fcd6e..7c074b4be819 100644
--- a/drivers/usb/host/xhci-debugfs.h
+++ b/drivers/usb/host/xhci-debugfs.h
@@ -91,6 +91,9 @@ struct xhci_file_map {
 struct xhci_ep_priv {
 	char			name[DEBUGFS_NAMELEN];
 	struct dentry		*root;
+	struct xhci_stream_info *stream_info;
+	struct xhci_ring	*show_ring;
+	unsigned int		stream_id;
 };
 
 struct xhci_slot_priv {
@@ -113,6 +116,9 @@ void xhci_debugfs_create_endpoint(struct xhci_hcd *xhci,
 void xhci_debugfs_remove_endpoint(struct xhci_hcd *xhci,
 				  struct xhci_virt_device *virt_dev,
 				  int ep_index);
+void xhci_debugfs_create_stream_files(struct xhci_hcd *xhci,
+				      struct xhci_virt_device *virt_dev,
+				      int ep_index);
 #else
 static inline void xhci_debugfs_init(struct xhci_hcd *xhci) { }
 static inline void xhci_debugfs_exit(struct xhci_hcd *xhci) { }
@@ -128,6 +134,10 @@ static inline void
 xhci_debugfs_remove_endpoint(struct xhci_hcd *xhci,
 			     struct xhci_virt_device *virt_dev,
 			     int ep_index) { }
+static inline void
+xhci_debugfs_create_stream_files(struct xhci_hcd *xhci,
+				 struct xhci_virt_device *virt_dev,
+				 int ep_index) { }
 #endif /* CONFIG_DEBUG_FS */
 
 #endif /* __LINUX_XHCI_DEBUGFS_H */
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index e88f4f953995..482fe8c5e3b4 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3533,6 +3533,7 @@ static int xhci_alloc_streams(struct usb_hcd *hcd, struct usb_device *udev,
 		xhci_dbg(xhci, "Slot %u ep ctx %u now has streams.\n",
 			 udev->slot_id, ep_index);
 		vdev->eps[ep_index].ep_state |= EP_HAS_STREAMS;
+		xhci_debugfs_create_stream_files(xhci, vdev, ep_index);
 	}
 	xhci_free_command(xhci, config_cmd);
 	spin_unlock_irqrestore(&xhci->lock, flags);
-- 
2.17.1