Merge tag 'usb-for-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-next

Felipe writes:

USB: changes for v5.8 merge window

Rather busy cycle. We have a total 99 non-merge commits going into v5.8
merge window. The majority of the changes are in dwc3 this around (31.7%
of all changes). It's composed mostly Thinh's recent updates to get dwc3
to behave correctly with stream transfers. We have also have Roger's for
Keystone platforms and Neil's updates for the meson glue layer.

Apart from those, we have the usual set of non-critical fixes, new
device IDs, spelling fixes all over the place.

Signed-off-by: Felipe Balbi <balbi@kernel.org>

* tag 'usb-for-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb: (99 commits)
  usb: dwc3: keystone: Turn on USB3 PHY before controller
  dt-bindings: usb: ti,keystone-dwc3.yaml: Add USB3.0 PHY property
  dt-bindings: usb: convert keystone-usb.txt to YAML
  usb: dwc3: gadget: Check for prepared TRBs
  usb: gadget: Fix issue with config_ep_by_speed function
  usb: cdns3: ep0: delete the redundant status stage
  usb: dwc2: Update Core Reset programming flow.
  usb: gadget: fsl: Fix a wrong judgment in fsl_udc_probe()
  usb: gadget: fix potential double-free in m66592_probe.
  usb: cdns3: Fix runtime PM imbalance on error
  usb: gadget: lpc32xx_udc: don't dereference ep pointer before null check
  usb: dwc3: Increase timeout for CmdAct cleared by device controller
  USB: dummy-hcd: use configurable endpoint naming scheme
  usb: cdns3: gadget: assign interrupt number to USB gadget structure
  usb: gadget: core: sync interrupt before unbind the udc
  arm64: dts: qcom: sc7180: Add interconnect properties for USB
  arm64: dts: qcom: sdm845: Add interconnect properties for USB
  dt-bindings: usb: qcom,dwc3: Introduce interconnect properties for Qualcomm DWC3 driver
  ARM: dts: at91: Remove the USB EP child node
  dt-bindings: usb: atmel: Mark EP child node as deprecated
  ...

33 files changed, 131 insertions, 101 deletions

diff --git a/drivers/usb/gadget/function/f_acm.c b/drivers/usb/gadget/function/f_acm.c
index 7c152c28b26c..200596ea9557 100644
--- a/drivers/usb/gadget/function/f_acm.c
+++ b/drivers/usb/gadget/function/f_acm.c
@@ -723,6 +723,20 @@ static void acm_free_func(struct usb_function *f)
 	kfree(acm);
 }
 
+static void acm_resume(struct usb_function *f)
+{
+	struct f_acm *acm = func_to_acm(f);
+
+	gserial_resume(&acm->port);
+}
+
+static void acm_suspend(struct usb_function *f)
+{
+	struct f_acm *acm = func_to_acm(f);
+
+	gserial_suspend(&acm->port);
+}
+
 static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
 {
 	struct f_serial_opts *opts;
@@ -750,6 +764,8 @@ static struct usb_function *acm_alloc_func(struct usb_function_instance *fi)
 	acm->port_num = opts->port_num;
 	acm->port.func.unbind = acm_unbind;
 	acm->port.func.free_func = acm_free_func;
+	acm->port.func.resume = acm_resume;
+	acm->port.func.suspend = acm_suspend;
 
 	return &acm->port.func;
 }
diff --git a/drivers/usb/gadget/function/f_eem.c b/drivers/usb/gadget/function/f_eem.c
index b81a91d504bd..cfcc4e81fb77 100644
--- a/drivers/usb/gadget/function/f_eem.c
+++ b/drivers/usb/gadget/function/f_eem.c
@@ -291,8 +291,6 @@ static int eem_bind(struct usb_configuration *c, struct usb_function *f)
 		goto fail;
 	eem->port.out_ep = ep;
 
-	status = -ENOMEM;
-
 	/* support all relevant hardware speeds... we expect that when
 	 * hardware is dual speed, all bulk-capable endpoints work at
 	 * both speeds
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 10f01f974f67..494f853f2206 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -2508,7 +2508,7 @@ static int __ffs_data_got_descs(struct ffs_data *ffs,
 		os_descs_count = get_unaligned_le32(data);
 		data += 4;
 		len -= 4;
-	};
+	}
 
 	/* Read descriptors */
 	raw_descs = data;
diff --git a/drivers/usb/gadget/function/f_serial.c b/drivers/usb/gadget/function/f_serial.c
index 1406255d0865..e62713846350 100644
--- a/drivers/usb/gadget/function/f_serial.c
+++ b/drivers/usb/gadget/function/f_serial.c
@@ -348,6 +348,20 @@ static void gser_unbind(struct usb_configuration *c, struct usb_function *f)
 	usb_free_all_descriptors(f);
 }
 
+static void gser_resume(struct usb_function *f)
+{
+	struct f_gser *gser = func_to_gser(f);
+
+	gserial_resume(&gser->port);
+}
+
+static void gser_suspend(struct usb_function *f)
+{
+	struct f_gser *gser = func_to_gser(f);
+
+	gserial_suspend(&gser->port);
+}
+
 static struct usb_function *gser_alloc(struct usb_function_instance *fi)
 {
 	struct f_gser	*gser;
@@ -369,6 +383,8 @@ static struct usb_function *gser_alloc(struct usb_function_instance *fi)
 	gser->port.func.set_alt = gser_set_alt;
 	gser->port.func.disable = gser_disable;
 	gser->port.func.free_func = gser_free;
+	gser->port.func.resume = gser_resume;
+	gser->port.func.suspend = gser_suspend;
 
 	return &gser->port.func;
 }
diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c
index 36504931b2d1..2979cbe4d95f 100644
--- a/drivers/usb/gadget/function/f_tcm.c
+++ b/drivers/usb/gadget/function/f_tcm.c
@@ -531,6 +531,7 @@ static int uasp_prepare_r_request(struct usbg_cmd *cmd)
 		stream->req_in->sg = se_cmd->t_data_sg;
 	}
 
+	stream->req_in->is_last = 1;
 	stream->req_in->complete = uasp_status_data_cmpl;
 	stream->req_in->length = se_cmd->data_length;
 	stream->req_in->context = cmd;
@@ -554,6 +555,7 @@ static void uasp_prepare_status(struct usbg_cmd *cmd)
 	 */
 	iu->len = cpu_to_be16(se_cmd->scsi_sense_length);
 	iu->status = se_cmd->scsi_status;
+	stream->req_status->is_last = 1;
 	stream->req_status->context = cmd;
 	stream->req_status->length = se_cmd->scsi_sense_length + 16;
 	stream->req_status->buf = iu;
@@ -991,6 +993,7 @@ static int usbg_prepare_w_request(struct usbg_cmd *cmd, struct usb_request *req)
 		req->sg = se_cmd->t_data_sg;
 	}
 
+	req->is_last = 1;
 	req->complete = usbg_data_write_cmpl;
 	req->length = se_cmd->data_length;
 	req->context = cmd;
diff --git a/drivers/usb/gadget/function/f_uvc.h b/drivers/usb/gadget/function/f_uvc.h
index a81a17765558..1db972d4beeb 100644
--- a/drivers/usb/gadget/function/f_uvc.h
+++ b/drivers/usb/gadget/function/f_uvc.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  *	f_uvc.h  --  USB Video Class Gadget driver
  *
diff --git a/drivers/usb/gadget/function/rndis.h b/drivers/usb/gadget/function/rndis.h
index c7e3a70ce6c1..f6167f7fea82 100644
--- a/drivers/usb/gadget/function/rndis.h
+++ b/drivers/usb/gadget/function/rndis.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * RNDIS	Definitions for Remote NDIS
  *
diff --git a/drivers/usb/gadget/function/u_audio.h b/drivers/usb/gadget/function/u_audio.h
index 81d3d4ed6dfb..5ea6b86f1fda 100644
--- a/drivers/usb/gadget/function/u_audio.h
+++ b/drivers/usb/gadget/function/u_audio.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * u_audio.h -- interface to USB gadget "ALSA sound card" utilities
  *
diff --git a/drivers/usb/gadget/function/u_ecm.h b/drivers/usb/gadget/function/u_ecm.h
index 098ece573a5e..77cfb89932be 100644
--- a/drivers/usb/gadget/function/u_ecm.h
+++ b/drivers/usb/gadget/function/u_ecm.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_ecm.h
  *
diff --git a/drivers/usb/gadget/function/u_eem.h b/drivers/usb/gadget/function/u_eem.h
index 921386a375cf..3bd85dfcd71c 100644
--- a/drivers/usb/gadget/function/u_eem.h
+++ b/drivers/usb/gadget/function/u_eem.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_eem.h
  *
diff --git a/drivers/usb/gadget/function/u_ether.h b/drivers/usb/gadget/function/u_ether.h
index 332307d54292..10dd640684e2 100644
--- a/drivers/usb/gadget/function/u_ether.h
+++ b/drivers/usb/gadget/function/u_ether.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * u_ether.h -- interface to USB gadget "ethernet link" utilities
  *
diff --git a/drivers/usb/gadget/function/u_ether_configfs.h b/drivers/usb/gadget/function/u_ether_configfs.h
index d8b92485b727..bd92b5703013 100644
--- a/drivers/usb/gadget/function/u_ether_configfs.h
+++ b/drivers/usb/gadget/function/u_ether_configfs.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_ether_configfs.h
  *
diff --git a/drivers/usb/gadget/function/u_fs.h b/drivers/usb/gadget/function/u_fs.h
index f9b0cf67360d..f102ec23f3af 100644
--- a/drivers/usb/gadget/function/u_fs.h
+++ b/drivers/usb/gadget/function/u_fs.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_fs.h
  *
diff --git a/drivers/usb/gadget/function/u_gether.h b/drivers/usb/gadget/function/u_gether.h
index ce4f07626f96..2f7a373ed449 100644
--- a/drivers/usb/gadget/function/u_gether.h
+++ b/drivers/usb/gadget/function/u_gether.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_gether.h
  *
diff --git a/drivers/usb/gadget/function/u_hid.h b/drivers/usb/gadget/function/u_hid.h
index 1594bfa312eb..84e6da302499 100644
--- a/drivers/usb/gadget/function/u_hid.h
+++ b/drivers/usb/gadget/function/u_hid.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_hid.h
  *
diff --git a/drivers/usb/gadget/function/u_midi.h b/drivers/usb/gadget/function/u_midi.h
index 29bf006c0a13..f6e14af7f566 100644
--- a/drivers/usb/gadget/function/u_midi.h
+++ b/drivers/usb/gadget/function/u_midi.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_midi.h
  *
diff --git a/drivers/usb/gadget/function/u_ncm.h b/drivers/usb/gadget/function/u_ncm.h
index 70da3201a1d0..5408854d8407 100644
--- a/drivers/usb/gadget/function/u_ncm.h
+++ b/drivers/usb/gadget/function/u_ncm.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_ncm.h
  *
diff --git a/drivers/usb/gadget/function/u_phonet.h b/drivers/usb/gadget/function/u_phonet.h
index 12fb613f85d1..c53233b37192 100644
--- a/drivers/usb/gadget/function/u_phonet.h
+++ b/drivers/usb/gadget/function/u_phonet.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * u_phonet.h - interface to Phonet
  *
diff --git a/drivers/usb/gadget/function/u_printer.h b/drivers/usb/gadget/function/u_printer.h
index 78797764f478..318205fb778e 100644
--- a/drivers/usb/gadget/function/u_printer.h
+++ b/drivers/usb/gadget/function/u_printer.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_printer.h
  *
diff --git a/drivers/usb/gadget/function/u_rndis.h b/drivers/usb/gadget/function/u_rndis.h
index 1e148b76f339..a8c409b2f52f 100644
--- a/drivers/usb/gadget/function/u_rndis.h
+++ b/drivers/usb/gadget/function/u_rndis.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_rndis.h
  *
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index 8167d379e115..3cfc6e2eba71 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -120,6 +120,8 @@ struct gs_port {
 	wait_queue_head_t	drain_wait;	/* wait while writes drain */
 	bool                    write_busy;
 	wait_queue_head_t	close_wait;
+	bool			suspended;	/* port suspended */
+	bool			start_delayed;	/* delay start when suspended */
 
 	/* REVISIT this state ... */
 	struct usb_cdc_line_coding port_line_coding;	/* 8-N-1 etc */
@@ -630,13 +632,19 @@ static int gs_open(struct tty_struct *tty, struct file *file)
 
 	/* if connected, start the I/O stream */
 	if (port->port_usb) {
-		struct gserial	*gser = port->port_usb;
-
-		pr_debug("gs_open: start ttyGS%d\n", port->port_num);
-		gs_start_io(port);
-
-		if (gser->connect)
-			gser->connect(gser);
+		/* if port is suspended, wait resume to start I/0 stream */
+		if (!port->suspended) {
+			struct gserial	*gser = port->port_usb;
+
+			pr_debug("gs_open: start ttyGS%d\n", port->port_num);
+			gs_start_io(port);
+
+			if (gser->connect)
+				gser->connect(gser);
+		} else {
+			pr_debug("delay start of ttyGS%d\n", port->port_num);
+			port->start_delayed = true;
+		}
 	}
 
 	pr_debug("gs_open: ttyGS%d (%p,%p)\n", port->port_num, tty, file);
@@ -680,7 +688,7 @@ raced_with_open:
 	pr_debug("gs_close: ttyGS%d (%p,%p) ...\n", port->port_num, tty, file);
 
 	gser = port->port_usb;
-	if (gser && gser->disconnect)
+	if (gser && !port->suspended && gser->disconnect)
 		gser->disconnect(gser);
 
 	/* wait for circular write buffer to drain, disconnect, or at
@@ -708,6 +716,7 @@ raced_with_open:
 	else
 		kfifo_reset(&port->port_write_buf);
 
+	port->start_delayed = false;
 	port->port.count = 0;
 	port->port.tty = NULL;
 
@@ -1403,6 +1412,38 @@ void gserial_disconnect(struct gserial *gser)
 }
 EXPORT_SYMBOL_GPL(gserial_disconnect);
 
+void gserial_suspend(struct gserial *gser)
+{
+	struct gs_port	*port = gser->ioport;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&port->port_lock, flags);
+	port->suspended = true;
+	spin_unlock_irqrestore(&port->port_lock, flags);
+}
+EXPORT_SYMBOL_GPL(gserial_suspend);
+
+void gserial_resume(struct gserial *gser)
+{
+	struct gs_port *port = gser->ioport;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&port->port_lock, flags);
+	port->suspended = false;
+	if (!port->start_delayed) {
+		spin_unlock_irqrestore(&port->port_lock, flags);
+		return;
+	}
+
+	pr_debug("delayed start ttyGS%d\n", port->port_num);
+	gs_start_io(port);
+	if (gser->connect)
+		gser->connect(gser);
+	port->start_delayed = false;
+	spin_unlock_irqrestore(&port->port_lock, flags);
+}
+EXPORT_SYMBOL_GPL(gserial_resume);
+
 static int userial_init(void)
 {
 	unsigned			i;
diff --git a/drivers/usb/gadget/function/u_serial.h b/drivers/usb/gadget/function/u_serial.h
index e5b08ab8cf7a..cadb76eecbc7 100644
--- a/drivers/usb/gadget/function/u_serial.h
+++ b/drivers/usb/gadget/function/u_serial.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * u_serial.h - interface to USB gadget "serial port"/TTY utilities
  *
@@ -68,6 +68,8 @@ ssize_t gserial_get_console(unsigned char port_num, char *page);
 /* connect/disconnect is handled by individual functions */
 int gserial_connect(struct gserial *, u8 port_num);
 void gserial_disconnect(struct gserial *);
+void gserial_suspend(struct gserial *p);
+void gserial_resume(struct gserial *p);
 
 /* functions are bound to configurations by a config or gadget driver */
 int gser_bind_config(struct usb_configuration *c, u8 port_num);
diff --git a/drivers/usb/gadget/function/u_tcm.h b/drivers/usb/gadget/function/u_tcm.h
index 3f7ccecb0f9b..2cd15d9a1c0d 100644
--- a/drivers/usb/gadget/function/u_tcm.h
+++ b/drivers/usb/gadget/function/u_tcm.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_tcm.h
  *
diff --git a/drivers/usb/gadget/function/u_uac1.h b/drivers/usb/gadget/function/u_uac1.h
index 6f1a9d73defe..39c0e29e1b46 100644
--- a/drivers/usb/gadget/function/u_uac1.h
+++ b/drivers/usb/gadget/function/u_uac1.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_uac1.h - Utility definitions for UAC1 function
  *
diff --git a/drivers/usb/gadget/function/u_uac1_legacy.h b/drivers/usb/gadget/function/u_uac1_legacy.h
index 5c1bdf46fe32..b5df9bcbbeba 100644
--- a/drivers/usb/gadget/function/u_uac1_legacy.h
+++ b/drivers/usb/gadget/function/u_uac1_legacy.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * u_uac1.h -- interface to USB gadget "ALSA AUDIO" utilities
  *
diff --git a/drivers/usb/gadget/function/u_uac2.h b/drivers/usb/gadget/function/u_uac2.h
index 82048791eb6e..b5035711172d 100644
--- a/drivers/usb/gadget/function/u_uac2.h
+++ b/drivers/usb/gadget/function/u_uac2.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_uac2.h
  *
diff --git a/drivers/usb/gadget/function/u_uvc.h b/drivers/usb/gadget/function/u_uvc.h
index 16da49a2fcf2..9a01a7d4f17f 100644
--- a/drivers/usb/gadget/function/u_uvc.h
+++ b/drivers/usb/gadget/function/u_uvc.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * u_uvc.h
  *
diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
index 1473d25ff17a..23ee25383c1f 100644
--- a/drivers/usb/gadget/function/uvc.h
+++ b/drivers/usb/gadget/function/uvc.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0+
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  *	uvc_gadget.h  --  USB Video Class Gadget driver
  *
@@ -77,6 +77,8 @@ struct uvc_video {
 	struct uvc_device *uvc;
 	struct usb_ep *ep;
 
+	struct work_struct pump;
+
 	/* Frame parameters */
 	u8 bpp;
 	u32 fcc;
diff --git a/drivers/usb/gadget/function/uvc_configfs.h b/drivers/usb/gadget/function/uvc_configfs.h
index 341391dbc81f..7e1d7ca29bf2 100644
--- a/drivers/usb/gadget/function/uvc_configfs.h
+++ b/drivers/usb/gadget/function/uvc_configfs.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * uvc_configfs.h
  *
diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c
index 495f0ec663ea..4ca89eab6159 100644
--- a/drivers/usb/gadget/function/uvc_v4l2.c
+++ b/drivers/usb/gadget/function/uvc_v4l2.c
@@ -169,7 +169,9 @@ uvc_v4l2_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
 	if (ret < 0)
 		return ret;
 
-	return uvcg_video_pump(video);
+	schedule_work(&video->pump);
+
+	return ret;
 }
 
 static int
diff --git a/drivers/usb/gadget/function/uvc_v4l2.h b/drivers/usb/gadget/function/uvc_v4l2.h
index 452d71059b3f..1576005b61fd 100644
--- a/drivers/usb/gadget/function/uvc_v4l2.h
+++ b/drivers/usb/gadget/function/uvc_v4l2.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  *	uvc_v4l2.h  --  USB Video Class Gadget driver
  *
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index 5c042f380708..633e23d58d86 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -142,44 +142,12 @@ static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
 	return ret;
 }
 
-/*
- * I somehow feel that synchronisation won't be easy to achieve here. We have
- * three events that control USB requests submission:
- *
- * - USB request completion: the completion handler will resubmit the request
- *   if a video buffer is available.
- *
- * - USB interface setting selection: in response to a SET_INTERFACE request,
- *   the handler will start streaming if a video buffer is available and if
- *   video is not currently streaming.
- *
- * - V4L2 buffer queueing: the driver will start streaming if video is not
- *   currently streaming.
- *
- * Race conditions between those 3 events might lead to deadlocks or other
- * nasty side effects.
- *
- * The "video currently streaming" condition can't be detected by the irqqueue
- * being empty, as a request can still be in flight. A separate "queue paused"
- * flag is thus needed.
- *
- * The paused flag will be set when we try to retrieve the irqqueue head if the
- * queue is empty, and cleared when we queue a buffer.
- *
- * The USB request completion handler will get the buffer at the irqqueue head
- * under protection of the queue spinlock. If the queue is empty, the streaming
- * paused flag will be set. Right after releasing the spinlock a userspace
- * application can queue a buffer. The flag will then cleared, and the ioctl
- * handler will restart the video stream.
- */
 static void
 uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
 {
 	struct uvc_video *video = req->context;
 	struct uvc_video_queue *queue = &video->queue;
-	struct uvc_buffer *buf;
 	unsigned long flags;
-	int ret;
 
 	switch (req->status) {
 	case 0:
@@ -188,39 +156,20 @@ uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
 	case -ESHUTDOWN:	/* disconnect from host. */
 		uvcg_dbg(&video->uvc->func, "VS request cancelled.\n");
 		uvcg_queue_cancel(queue, 1);
-		goto requeue;
+		break;
 
 	default:
 		uvcg_info(&video->uvc->func,
 			  "VS request completed with status %d.\n",
 			  req->status);
 		uvcg_queue_cancel(queue, 0);
-		goto requeue;
 	}
 
-	spin_lock_irqsave(&video->queue.irqlock, flags);
-	buf = uvcg_queue_head(&video->queue);
-	if (buf == NULL) {
-		spin_unlock_irqrestore(&video->queue.irqlock, flags);
-		goto requeue;
-	}
-
-	video->encode(req, video, buf);
-
-	ret = uvcg_video_ep_queue(video, req);
-	spin_unlock_irqrestore(&video->queue.irqlock, flags);
-
-	if (ret < 0) {
-		uvcg_queue_cancel(queue, 0);
-		goto requeue;
-	}
-
-	return;
-
-requeue:
 	spin_lock_irqsave(&video->req_lock, flags);
 	list_add_tail(&req->list, &video->req_free);
 	spin_unlock_irqrestore(&video->req_lock, flags);
+
+	schedule_work(&video->pump);
 }
 
 static int
@@ -294,18 +243,15 @@ error:
  * This function fills the available USB requests (listed in req_free) with
  * video data from the queued buffers.
  */
-int uvcg_video_pump(struct uvc_video *video)
+static void uvcg_video_pump(struct work_struct *work)
 {
+	struct uvc_video *video = container_of(work, struct uvc_video, pump);
 	struct uvc_video_queue *queue = &video->queue;
 	struct usb_request *req;
 	struct uvc_buffer *buf;
 	unsigned long flags;
 	int ret;
 
-	/* FIXME TODO Race between uvcg_video_pump and requests completion
-	 * handler ???
-	 */
-
 	while (1) {
 		/* Retrieve the first available USB request, protected by the
 		 * request lock.
@@ -313,7 +259,7 @@ int uvcg_video_pump(struct uvc_video *video)
 		spin_lock_irqsave(&video->req_lock, flags);
 		if (list_empty(&video->req_free)) {
 			spin_unlock_irqrestore(&video->req_lock, flags);
-			return 0;
+			return;
 		}
 		req = list_first_entry(&video->req_free, struct usb_request,
 					list);
@@ -345,7 +291,7 @@ int uvcg_video_pump(struct uvc_video *video)
 	spin_lock_irqsave(&video->req_lock, flags);
 	list_add_tail(&req->list, &video->req_free);
 	spin_unlock_irqrestore(&video->req_lock, flags);
-	return 0;
+	return;
 }
 
 /*
@@ -363,6 +309,9 @@ int uvcg_video_enable(struct uvc_video *video, int enable)
 	}
 
 	if (!enable) {
+		cancel_work_sync(&video->pump);
+		uvcg_queue_cancel(&video->queue, 0);
+
 		for (i = 0; i < UVC_NUM_REQUESTS; ++i)
 			if (video->req[i])
 				usb_ep_dequeue(video->ep, video->req[i]);
@@ -384,7 +333,9 @@ int uvcg_video_enable(struct uvc_video *video, int enable)
 	} else
 		video->encode = uvc_video_encode_isoc;
 
-	return uvcg_video_pump(video);
+	schedule_work(&video->pump);
+
+	return ret;
 }
 
 /*
@@ -394,6 +345,7 @@ int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc)
 {
 	INIT_LIST_HEAD(&video->req_free);
 	spin_lock_init(&video->req_lock);
+	INIT_WORK(&video->pump, uvcg_video_pump);
 
 	video->uvc = uvc;
 	video->fcc = V4L2_PIX_FMT_YUYV;
diff --git a/drivers/usb/gadget/function/uvc_video.h b/drivers/usb/gadget/function/uvc_video.h
index dff12103f696..03adeefa343b 100644
--- a/drivers/usb/gadget/function/uvc_video.h
+++ b/drivers/usb/gadget/function/uvc_video.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  *	uvc_video.h  --  USB Video Class Gadget driver
  *
@@ -14,8 +14,6 @@
 
 struct uvc_video;
 
-int uvcg_video_pump(struct uvc_video *video);
-
 int uvcg_video_enable(struct uvc_video *video, int enable);
 
 int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc);