[PATCH AUTOSEL 4.14 018/108] usblp: poison URBs upon disconnect

[PATCH AUTOSEL 4.14 018/108] usblp: poison URBs upon disconnect

[Sasha Levin]

From: Oliver Neukum <oneukum@suse.com>

[ Upstream commit 296a193b06120aa6ae7cf5c0d7b5e5b55968026e ]

syzkaller reported an URB that should have been killed to be active.
We do not understand it, but this should fix the issue if it is real.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reported-by: syzbot+be5b5f86a162a6c281e6@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20200507085806.5793-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/class/usblp.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index 5e456a83779d..b0471ce34011 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -481,7 +481,8 @@ static int usblp_release(struct inode *inode, struct file *file)
 	usb_autopm_put_interface(usblp->intf);
 
 	if (!usblp->present)		/* finish cleanup from disconnect */
-		usblp_cleanup(usblp);
+		usblp_cleanup(usblp);	/* any URBs must be dead */
+
 	mutex_unlock(&usblp_mutex);
 	return 0;
 }
@@ -1388,9 +1389,11 @@ static void usblp_disconnect(struct usb_interface *intf)
 
 	usblp_unlink_urbs(usblp);
 	mutex_unlock(&usblp->mut);
+	usb_poison_anchored_urbs(&usblp->urbs);
 
 	if (!usblp->used)
 		usblp_cleanup(usblp);
+
 	mutex_unlock(&usblp_mutex);
 }
 
-- 
2.25.1

[PATCH AUTOSEL 4.14 063/108] usb/ohci-platform: Fix a warning when hibernating

[Sasha Levin]

From: Qais Yousef <qais.yousef@arm.com>

[ Upstream commit 1cb3b0095c3d0bb96912bfbbce4fc006d41f367c ]

The following warning was observed when attempting to suspend to disk
using a USB flash as a swap device.

[  111.779649] ------------[ cut here ]------------
[  111.788382] URB (____ptrval____) submitted while active
[  111.796646] WARNING: CPU: 3 PID: 365 at drivers/usb/core/urb.c:363 usb_submit_urb+0x3d8/0x590
[  111.805417] Modules linked in:
[  111.808584] CPU: 3 PID: 365 Comm: kworker/3:2 Not tainted 5.6.0-rc6-00002-gdfd1731f9a3e-dirty #545
[  111.817796] Hardware name: ARM Juno development board (r2) (DT)
[  111.823896] Workqueue: usb_hub_wq hub_event
[  111.828217] pstate: 60000005 (nZCv daif -PAN -UAO)
[  111.833156] pc : usb_submit_urb+0x3d8/0x590
[  111.837471] lr : usb_submit_urb+0x3d8/0x590
[  111.841783] sp : ffff800018de38b0
[  111.845205] x29: ffff800018de38b0 x28: 0000000000000003
[  111.850682] x27: ffff000970530b20 x26: ffff8000133fd000
[  111.856159] x25: ffff8000133fd000 x24: ffff800018de3b38
[  111.861635] x23: 0000000000000004 x22: 0000000000000c00
[  111.867112] x21: 0000000000000000 x20: 00000000fffffff0
[  111.872589] x19: ffff0009704e7a00 x18: ffffffffffffffff
[  111.878065] x17: 00000000a7c8f4bc x16: 000000002af33de8
[  111.883542] x15: ffff8000133fda88 x14: 0720072007200720
[  111.889019] x13: 0720072007200720 x12: 0720072007200720
[  111.894496] x11: 0000000000000000 x10: 00000000a5286134
[  111.899973] x9 : 0000000000000002 x8 : ffff000970c837a0
[  111.905449] x7 : 0000000000000000 x6 : ffff800018de3570
[  111.910926] x5 : 0000000000000001 x4 : 0000000000000003
[  111.916401] x3 : 0000000000000000 x2 : ffff800013427118
[  111.921879] x1 : 9d4e965b4b7d7c00 x0 : 0000000000000000
[  111.927356] Call trace:
[  111.929892]  usb_submit_urb+0x3d8/0x590
[  111.933852]  hub_activate+0x108/0x7f0
[  111.937633]  hub_resume+0xac/0x148
[  111.941149]  usb_resume_interface.isra.10+0x60/0x138
[  111.946265]  usb_resume_both+0xe4/0x140
[  111.950225]  usb_runtime_resume+0x24/0x30
[  111.954365]  __rpm_callback+0xdc/0x138
[  111.958236]  rpm_callback+0x34/0x98
[  111.961841]  rpm_resume+0x4a8/0x720
[  111.965445]  rpm_resume+0x50c/0x720
[  111.969049]  __pm_runtime_resume+0x4c/0xb8
[  111.973276]  usb_autopm_get_interface+0x28/0x60
[  111.977948]  hub_event+0x80/0x16d8
[  111.981466]  process_one_work+0x2a4/0x748
[  111.985604]  worker_thread+0x48/0x498
[  111.989387]  kthread+0x13c/0x140
[  111.992725]  ret_from_fork+0x10/0x18
[  111.996415] irq event stamp: 354
[  111.999756] hardirqs last  enabled at (353): [<ffff80001019ea1c>] console_unlock+0x504/0x5b8
[  112.008441] hardirqs last disabled at (354): [<ffff8000100a95d0>] do_debug_exception+0x1a8/0x258
[  112.017479] softirqs last  enabled at (350): [<ffff8000100818a4>] __do_softirq+0x4bc/0x568
[  112.025984] softirqs last disabled at (343): [<ffff8000101145a4>] irq_exit+0x144/0x150
[  112.034129] ---[ end trace dc96030b9cf6c8a3 ]---

The problem was tracked down to a missing call to
pm_runtime_set_active() on resume in ohci-platform.

Link: https://lore.kernel.org/lkml/20200323143857.db5zphxhq4hz3hmd@e107158-lin.cambridge.arm.com/
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
CC: Tony Prisk <linux@prisktech.co.nz>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Mathias Nyman <mathias.nyman@intel.com>
CC: Oliver Neukum <oneukum@suse.de>
CC: linux-arm-kernel@lists.infradead.org
CC: linux-usb@vger.kernel.org
CC: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20200518154931.6144-1-qais.yousef@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/host/ohci-platform.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/usb/host/ohci-platform.c b/drivers/usb/host/ohci-platform.c
index 61fe2b985070..742cefa22c2b 100644
--- a/drivers/usb/host/ohci-platform.c
+++ b/drivers/usb/host/ohci-platform.c
@@ -355,6 +355,11 @@ static int ohci_platform_resume(struct device *dev)
 	}
 
 	ohci_resume(hcd, false);
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
 	return 0;
 }
 #endif /* CONFIG_PM_SLEEP */
-- 
2.25.1

[PATCH AUTOSEL 4.14 065/108] USB: host: ehci-mxc: Add error handling in ehci_mxc_drv_probe()

[Sasha Levin]

From: Tang Bin <tangbin@cmss.chinamobile.com>

[ Upstream commit d49292025f79693d3348f8e2029a8b4703be0f0a ]

The function ehci_mxc_drv_probe() does not perform sufficient error
checking after executing platform_get_irq(), thus fix it.

Fixes: 7e8d5cd93fac ("USB: Add EHCI support for MX27 and MX31 based boards")
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Link: https://lore.kernel.org/r/20200513132647.5456-1-tangbin@cmss.chinamobile.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/host/ehci-mxc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
index c7a9b31eeaef..637079a35003 100644
--- a/drivers/usb/host/ehci-mxc.c
+++ b/drivers/usb/host/ehci-mxc.c
@@ -63,6 +63,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
 	}
 
 	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
 	hcd = usb_create_hcd(&ehci_mxc_hc_driver, dev, dev_name(dev));
 	if (!hcd)
-- 
2.25.1

[PATCH AUTOSEL 4.14 073/108] usb: dwc2: gadget: move gadget resume after the core is in L0 state

[Sasha Levin]

From: Fabrice Gasnier <fabrice.gasnier@st.com>

[ Upstream commit 8c935deacebb8fac8f41378701eb79d12f3c2e2d ]

When the remote wakeup interrupt is triggered, lx_state is resumed from L2
to L0 state. But when the gadget resume is called, lx_state is still L2.
This prevents the resume callback to queue any request. Any attempt
to queue a request from resume callback will result in:
- "submit request only in active state" debug message to be issued
- dwc2_hsotg_ep_queue() returns -EAGAIN

Call the gadget resume routine after the core is in L0 state.

Fixes: f81f46e1f530 ("usb: dwc2: implement hibernation during bus suspend/resume")

Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/dwc2/core_intr.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
index b8bcb007c92a..e3e0a3ab31da 100644
--- a/drivers/usb/dwc2/core_intr.c
+++ b/drivers/usb/dwc2/core_intr.c
@@ -364,10 +364,13 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
 			if (ret && (ret != -ENOTSUPP))
 				dev_err(hsotg->dev, "exit hibernation failed\n");
 
+			/* Change to L0 state */
+			hsotg->lx_state = DWC2_L0;
 			call_gadget(hsotg, resume);
+		} else {
+			/* Change to L0 state */
+			hsotg->lx_state = DWC2_L0;
 		}
-		/* Change to L0 state */
-		hsotg->lx_state = DWC2_L0;
 	} else {
 		if (hsotg->params.hibernation)
 			return;
-- 
2.25.1

[PATCH AUTOSEL 4.14 074/108] USB: gadget: udc: s3c2410_udc: Remove pointless NULL check in s3c2410_udc_nuke

[Sasha Levin]

From: Nathan Chancellor <natechancellor@gmail.com>

[ Upstream commit 7a0fbcf7c308920bc6116b3a5fb21c8cc5fec128 ]

Clang warns:

drivers/usb/gadget/udc/s3c2410_udc.c:255:11: warning: comparison of
address of 'ep->queue' equal to a null pointer is always false
[-Wtautological-pointer-compare]
        if (&ep->queue == NULL)
             ~~~~^~~~~    ~~~~
1 warning generated.

It is not wrong, queue is not a pointer so if ep is not NULL, the
address of queue cannot be NULL. No other driver does a check like this
and this check has been around since the driver was first introduced,
presumably with no issues so it does not seem like this check should be
something else. Just remove it.

Commit afe956c577b2d ("kbuild: Enable -Wtautological-compare") exposed
this but it is not the root cause of the warning.

Fixes: 3fc154b6b8134 ("USB Gadget driver for Samsung s3c2410 ARM SoC")
Link: https://github.com/ClangBuiltLinux/linux/issues/1004
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/gadget/udc/s3c2410_udc.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/usb/gadget/udc/s3c2410_udc.c b/drivers/usb/gadget/udc/s3c2410_udc.c
index 394abd5d65c0..cf12ca567e69 100644
--- a/drivers/usb/gadget/udc/s3c2410_udc.c
+++ b/drivers/usb/gadget/udc/s3c2410_udc.c
@@ -268,10 +268,6 @@ static void s3c2410_udc_done(struct s3c2410_ep *ep,
 static void s3c2410_udc_nuke(struct s3c2410_udc *udc,
 		struct s3c2410_ep *ep, int status)
 {
-	/* Sanity check */
-	if (&ep->queue == NULL)
-		return;
-
 	while (!list_empty(&ep->queue)) {
 		struct s3c2410_request *req;
 		req = list_entry(ep->queue.next, struct s3c2410_request,
-- 
2.25.1

[PATCH AUTOSEL 4.14 075/108] usb: gadget: lpc32xx_udc: don't dereference ep pointer before null check

[Sasha Levin]

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit eafa80041645cd7604c4357b1a0cd4a3c81f2227 ]

Currently pointer ep is being dereferenced before it is null checked
leading to a null pointer dereference issue.  Fix this by only assigning
pointer udc once ep is known to be not null.  Also remove a debug
message that requires a valid udc which may not be possible at that
point.

Addresses-Coverity: ("Dereference before null check")
Fixes: 24a28e428351 ("USB: gadget driver for LPC32xx")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/gadget/udc/lpc32xx_udc.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/gadget/udc/lpc32xx_udc.c b/drivers/usb/gadget/udc/lpc32xx_udc.c
index ac2aa04ca657..710793161795 100644
--- a/drivers/usb/gadget/udc/lpc32xx_udc.c
+++ b/drivers/usb/gadget/udc/lpc32xx_udc.c
@@ -1615,17 +1615,17 @@ static int lpc32xx_ep_enable(struct usb_ep *_ep,
 			     const struct usb_endpoint_descriptor *desc)
 {
 	struct lpc32xx_ep *ep = container_of(_ep, struct lpc32xx_ep, ep);
-	struct lpc32xx_udc *udc = ep->udc;
+	struct lpc32xx_udc *udc;
 	u16 maxpacket;
 	u32 tmp;
 	unsigned long flags;
 
 	/* Verify EP data */
 	if ((!_ep) || (!ep) || (!desc) ||
-	    (desc->bDescriptorType != USB_DT_ENDPOINT)) {
-		dev_dbg(udc->dev, "bad ep or descriptor\n");
+	    (desc->bDescriptorType != USB_DT_ENDPOINT))
 		return -EINVAL;
-	}
+
+	udc = ep->udc;
 	maxpacket = usb_endpoint_maxp(desc);
 	if ((maxpacket == 0) || (maxpacket > ep->maxpacket)) {
 		dev_dbg(udc->dev, "bad ep descriptor's packet size\n");
@@ -1873,7 +1873,7 @@ static int lpc32xx_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
 static int lpc32xx_ep_set_halt(struct usb_ep *_ep, int value)
 {
 	struct lpc32xx_ep *ep = container_of(_ep, struct lpc32xx_ep, ep);
-	struct lpc32xx_udc *udc = ep->udc;
+	struct lpc32xx_udc *udc;
 	unsigned long flags;
 
 	if ((!ep) || (ep->hwep_num <= 1))
@@ -1883,6 +1883,7 @@ static int lpc32xx_ep_set_halt(struct usb_ep *_ep, int value)
 	if (ep->is_in)
 		return -EAGAIN;
 
+	udc = ep->udc;
 	spin_lock_irqsave(&udc->lock, flags);
 
 	if (value == 1) {
-- 
2.25.1

[PATCH AUTOSEL 4.14 076/108] usb: gadget: fix potential double-free in m66592_probe.

[Sasha Levin]

From: Qiushi Wu <wu000273@umn.edu>

[ Upstream commit 44734a594196bf1d474212f38fe3a0d37a73278b ]

m66592_free_request() is called under label "err_add_udc"
and "clean_up", and m66592->ep0_req is not set to NULL after
first free, leading to a double-free. Fix this issue by
setting m66592->ep0_req to NULL after the first free.

Fixes: 0f91349b89f3 ("usb: gadget: convert all users to the new udc infrastructure")
Signed-off-by: Qiushi Wu <wu000273@umn.edu>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/gadget/udc/m66592-udc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/udc/m66592-udc.c b/drivers/usb/gadget/udc/m66592-udc.c
index 46ce7bc15f2b..53abad98af6d 100644
--- a/drivers/usb/gadget/udc/m66592-udc.c
+++ b/drivers/usb/gadget/udc/m66592-udc.c
@@ -1672,7 +1672,7 @@ static int m66592_probe(struct platform_device *pdev)
 
 err_add_udc:
 	m66592_free_request(&m66592->ep[0].ep, m66592->ep0_req);
-
+	m66592->ep0_req = NULL;
 clean_up3:
 	if (m66592->pdata->on_chip) {
 		clk_disable(m66592->clk);
-- 
2.25.1

[PATCH AUTOSEL 4.14 077/108] usb: gadget: Fix issue with config_ep_by_speed function

[Sasha Levin]

From: Pawel Laszczak <pawell@cadence.com>

[ Upstream commit 5d363120aa548ba52d58907a295eee25f8207ed2 ]

This patch adds new config_ep_by_speed_and_alt function which
extends the config_ep_by_speed about alt parameter.
This additional parameter allows to find proper usb_ss_ep_comp_descriptor.

Problem has appeared during testing f_tcm (BOT/UAS) driver function.

f_tcm function for SS use array of headers for both  BOT/UAS alternate
setting:

static struct usb_descriptor_header *uasp_ss_function_desc[] = {
        (struct usb_descriptor_header *) &bot_intf_desc,
        (struct usb_descriptor_header *) &uasp_ss_bi_desc,
        (struct usb_descriptor_header *) &bot_bi_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_ss_bo_desc,
        (struct usb_descriptor_header *) &bot_bo_ep_comp_desc,

        (struct usb_descriptor_header *) &uasp_intf_desc,
        (struct usb_descriptor_header *) &uasp_ss_bi_desc,
        (struct usb_descriptor_header *) &uasp_bi_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_bi_pipe_desc,
        (struct usb_descriptor_header *) &uasp_ss_bo_desc,
        (struct usb_descriptor_header *) &uasp_bo_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_bo_pipe_desc,
        (struct usb_descriptor_header *) &uasp_ss_status_desc,
        (struct usb_descriptor_header *) &uasp_status_in_ep_comp_desc,
        (struct usb_descriptor_header *) &uasp_status_pipe_desc,
        (struct usb_descriptor_header *) &uasp_ss_cmd_desc,
        (struct usb_descriptor_header *) &uasp_cmd_comp_desc,
        (struct usb_descriptor_header *) &uasp_cmd_pipe_desc,
        NULL,
};

The first 5 descriptors are associated with BOT alternate setting,
and others are associated with UAS.

During handling UAS alternate setting f_tcm driver invokes
config_ep_by_speed and this function sets incorrect companion endpoint
descriptor in usb_ep object.

Instead setting ep->comp_desc to uasp_bi_ep_comp_desc function in this
case set ep->comp_desc to uasp_ss_bi_desc.

This is due to the fact that it searches endpoint based on endpoint
address:

        for_each_ep_desc(speed_desc, d_spd) {
                chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
                if (chosen_desc->bEndpoitAddress == _ep->address)
                        goto ep_found;
        }

And in result it uses the descriptor from BOT alternate setting
instead UAS.

Finally, it causes that controller driver during enabling endpoints
detect that just enabled endpoint for bot.

Signed-off-by: Jayshri Pawar <jpawar@cadence.com>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/gadget/composite.c | 78 ++++++++++++++++++++++++++--------
 include/linux/usb/composite.h  |  3 ++
 2 files changed, 64 insertions(+), 17 deletions(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index c1f037af9702..7d2715e899bb 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -100,40 +100,43 @@ function_descriptors(struct usb_function *f,
 }
 
 /**
- * next_ep_desc() - advance to the next EP descriptor
+ * next_desc() - advance to the next desc_type descriptor
  * @t: currect pointer within descriptor array
+ * @desc_type: descriptor type
  *
- * Return: next EP descriptor or NULL
+ * Return: next desc_type descriptor or NULL
  *
- * Iterate over @t until either EP descriptor found or
+ * Iterate over @t until either desc_type descriptor found or
  * NULL (that indicates end of list) encountered
  */
 static struct usb_descriptor_header**
-next_ep_desc(struct usb_descriptor_header **t)
+next_desc(struct usb_descriptor_header **t, u8 desc_type)
 {
 	for (; *t; t++) {
-		if ((*t)->bDescriptorType == USB_DT_ENDPOINT)
+		if ((*t)->bDescriptorType == desc_type)
 			return t;
 	}
 	return NULL;
 }
 
 /*
- * for_each_ep_desc()- iterate over endpoint descriptors in the
- *		descriptors list
- * @start:	pointer within descriptor array.
- * @ep_desc:	endpoint descriptor to use as the loop cursor
+ * for_each_desc() - iterate over desc_type descriptors in the
+ * descriptors list
+ * @start: pointer within descriptor array.
+ * @iter_desc: desc_type descriptor to use as the loop cursor
+ * @desc_type: wanted descriptr type
  */
-#define for_each_ep_desc(start, ep_desc) \
-	for (ep_desc = next_ep_desc(start); \
-	      ep_desc; ep_desc = next_ep_desc(ep_desc+1))
+#define for_each_desc(start, iter_desc, desc_type) \
+	for (iter_desc = next_desc(start, desc_type); \
+	     iter_desc; iter_desc = next_desc(iter_desc + 1, desc_type))
 
 /**
- * config_ep_by_speed() - configures the given endpoint
+ * config_ep_by_speed_and_alt() - configures the given endpoint
  * according to gadget speed.
  * @g: pointer to the gadget
  * @f: usb function
  * @_ep: the endpoint to configure
+ * @alt: alternate setting number
  *
  * Return: error code, 0 on success
  *
@@ -146,11 +149,13 @@ next_ep_desc(struct usb_descriptor_header **t)
  * Note: the supplied function should hold all the descriptors
  * for supported speeds
  */
-int config_ep_by_speed(struct usb_gadget *g,
-			struct usb_function *f,
-			struct usb_ep *_ep)
+int config_ep_by_speed_and_alt(struct usb_gadget *g,
+				struct usb_function *f,
+				struct usb_ep *_ep,
+				u8 alt)
 {
 	struct usb_endpoint_descriptor *chosen_desc = NULL;
+	struct usb_interface_descriptor *int_desc = NULL;
 	struct usb_descriptor_header **speed_desc = NULL;
 
 	struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
@@ -186,8 +191,21 @@ int config_ep_by_speed(struct usb_gadget *g,
 	default:
 		speed_desc = f->fs_descriptors;
 	}
+
+	/* find correct alternate setting descriptor */
+	for_each_desc(speed_desc, d_spd, USB_DT_INTERFACE) {
+		int_desc = (struct usb_interface_descriptor *)*d_spd;
+
+		if (int_desc->bAlternateSetting == alt) {
+			speed_desc = d_spd;
+			goto intf_found;
+		}
+	}
+	return -EIO;
+
+intf_found:
 	/* find descriptors */
-	for_each_ep_desc(speed_desc, d_spd) {
+	for_each_desc(speed_desc, d_spd, USB_DT_ENDPOINT) {
 		chosen_desc = (struct usb_endpoint_descriptor *)*d_spd;
 		if (chosen_desc->bEndpointAddress == _ep->address)
 			goto ep_found;
@@ -240,6 +258,32 @@ int config_ep_by_speed(struct usb_gadget *g,
 	}
 	return 0;
 }
+EXPORT_SYMBOL_GPL(config_ep_by_speed_and_alt);
+
+/**
+ * config_ep_by_speed() - configures the given endpoint
+ * according to gadget speed.
+ * @g: pointer to the gadget
+ * @f: usb function
+ * @_ep: the endpoint to configure
+ *
+ * Return: error code, 0 on success
+ *
+ * This function chooses the right descriptors for a given
+ * endpoint according to gadget speed and saves it in the
+ * endpoint desc field. If the endpoint already has a descriptor
+ * assigned to it - overwrites it with currently corresponding
+ * descriptor. The endpoint maxpacket field is updated according
+ * to the chosen descriptor.
+ * Note: the supplied function should hold all the descriptors
+ * for supported speeds
+ */
+int config_ep_by_speed(struct usb_gadget *g,
+			struct usb_function *f,
+			struct usb_ep *_ep)
+{
+	return config_ep_by_speed_and_alt(g, f, _ep, 0);
+}
 EXPORT_SYMBOL_GPL(config_ep_by_speed);
 
 /**
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 590d313b5f39..a865698361c1 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -248,6 +248,9 @@ int usb_function_activate(struct usb_function *);
 
 int usb_interface_id(struct usb_configuration *, struct usb_function *);
 
+int config_ep_by_speed_and_alt(struct usb_gadget *g, struct usb_function *f,
+				struct usb_ep *_ep, u8 alt);
+
 int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
 			struct usb_ep *_ep);
 
-- 
2.25.1