[v3] usb: gadget: uvc: add bulk transfer support

Commit Message

Jing Leng May 13, 2022, 12:42 a.m. UTC

From: Jing Leng <[e-mail]>

The video data endpoint of uvc can be implemented as either an
isochronous or a bulk endpoint.

The transmission speed of bulk mode is faster than isochronous mode.
I tested the speed with cdns3 (USB 3.2 Gen1), it's difficult to reach
2 Gbps in the isochronous mode, and it can exceed 4 Gbps in the bulk
mode.

A VideoStreaming interface with isochronous endpoints must have alternate
settings that can be used to change certain characteristics of the
interface and underlying endpoint(s). A typical use of alternate settings
is to provide a way to change the bandwidth requirements an active
isochronous pipe imposes on the USB.

A VideoStreaming interface containing a bulk endpoint for streaming shall
support only alternate setting zero. Additional alternate settings
containing bulk endpoints are not permitted in a device that is compliant
with the Video Class specification.

In user space, isochronous/bulk modes are handled a little differently:

1. APP prepares buffers and streams when it receives an UVC_EVENT_STREAMON
message in the isochronous mode, but APP should do them when it receives a
SET_CUR request of UVC_VS_COMMIT_CONTROL due to no UVC_EVENT_STREAMON
message reported from the kernel in the bulk mode (Do them only once).

2. In Addition, APP should set the value of dwMaxPayloadTransferSize to
streaming_maxpacket in the isochronous mode or streaming_bulk_mult * 1024
in the bulk mode.

Here shows an example of the configfs differences:
  if [ $BULK -eq 1 ]; then
      echo 128 > functions/$FUNC/streaming_bulk_mult
  else
      echo 1024 > functions/$FUNC/streaming_maxpacket
  fi

Signed-off-by: Jing Leng <[e-mail]>
---
ChangeLog v2->v3:
- Mistakenly deleted the definition of i and USBDHDR when porting from my workdir.
- Reported-by: kernel test robot <[e-mail]>
ChangeLog v1->v2:
- Handle imagesize in uvc_v4l2_set_format. If it's not handled,
- switching from low resolution to high resolution will fail to play.
---
 .../ABI/testing/configfs-usb-gadget-uvc       |   1 +
 Documentation/usb/gadget-testing.rst          |   4 +
 drivers/usb/gadget/function/f_uvc.c           | 248 ++++++++++++------
 drivers/usb/gadget/function/u_uvc.h           |   1 +
 drivers/usb/gadget/function/uvc_configfs.c    |   2 +
 drivers/usb/gadget/function/uvc_queue.c       |   4 +-
 drivers/usb/gadget/function/uvc_v4l2.c        |   8 +
 7 files changed, 186 insertions(+), 82 deletions(-)

Comments

Greg KH Oct. 25, 2022, 10:32 a.m. UTC | #1

On Tue, Oct 25, 2022 at 05:05:01PM +0800, [e-mail] wrote:
> From: Jing Leng <[e-mail]>

This email address does not match your From: address on the email, _AND_
that email address does not validate as actually being from that
address.

So this really looks like a "fake" email sent to us.  How can we know
differently?

Please work with your company email admins to fix up their systems so
you can properly send from your domain.  Then we can take your patches.

thanks,

greg k-h

Patch

diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uvc b/Documentation/ABI/testing/configfs-usb-gadget-uvc
index 889ed45be4ca..52ca04a619ff 100644
--- a/Documentation/ABI/testing/configfs-usb-gadget-uvc
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uvc
@@ -7,6 +7,7 @@  Description:	UVC function directory
 		streaming_maxburst	0..15 (ss only)
 		streaming_maxpacket	1..1023 (fs), 1..3072 (hs/ss)
 		streaming_interval	1..16
+		streaming_bulk_mult	0..0x3fffffU
 		===================	=============================
 
 What:		/config/usb-gadget/gadget/functions/uvc.name/control
diff --git a/Documentation/usb/gadget-testing.rst b/Documentation/usb/gadget-testing.rst
index c6d034abce3a..2cbe3e2e05c3 100644
--- a/Documentation/usb/gadget-testing.rst
+++ b/Documentation/usb/gadget-testing.rst
@@ -787,6 +787,10 @@  The uvc function provides these attributes in its function directory:
 	streaming_maxpacket maximum packet size this endpoint is capable of
 			    sending or receiving when this configuration is
 			    selected
+	streaming_bulk_mult Multiples to configure max_payload_size. If it's
+			    0, the transport mode is isochronous; otherwise
+			    the transport mode is bulk and max_payload_size
+			    is equal to streaming_bulk_mult * 1024.
 	=================== ================================================
 
 There are also "control" and "streaming" subdirectories, each of which contain
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 71bb5e477dba..2c54b482a902 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -30,6 +30,8 @@ 
 #include "uvc_v4l2.h"
 #include "uvc_video.h"
 
+#define USBDHDR(p) ((struct usb_descriptor_header *)(p))
+
 unsigned int uvc_gadget_trace_param;
 module_param_named(trace, uvc_gadget_trace_param, uint, 0644);
 MODULE_PARM_DESC(trace, "Trace level bitmask");
@@ -178,19 +180,19 @@  static struct usb_ss_ep_comp_descriptor uvc_ss_streaming_comp = {
 	 */
 };
 
-static const struct usb_descriptor_header * const uvc_fs_streaming[] = {
+static const struct usb_descriptor_header *uvc_fs_streaming[] = {
 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
 	(struct usb_descriptor_header *) &uvc_fs_streaming_ep,
 	NULL,
 };
 
-static const struct usb_descriptor_header * const uvc_hs_streaming[] = {
+static const struct usb_descriptor_header *uvc_hs_streaming[] = {
 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
 	(struct usb_descriptor_header *) &uvc_hs_streaming_ep,
 	NULL,
 };
 
-static const struct usb_descriptor_header * const uvc_ss_streaming[] = {
+static const struct usb_descriptor_header *uvc_ss_streaming[] = {
 	(struct usb_descriptor_header *) &uvc_streaming_intf_alt1,
 	(struct usb_descriptor_header *) &uvc_ss_streaming_ep,
 	(struct usb_descriptor_header *) &uvc_ss_streaming_comp,
@@ -251,9 +253,12 @@  uvc_function_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 
 void uvc_function_setup_continue(struct uvc_device *uvc)
 {
+	struct f_uvc_opts *opts = fi_to_f_uvc_opts(uvc->func.fi);
 	struct usb_composite_dev *cdev = uvc->func.config->cdev;
 
-	usb_composite_setup_continue(cdev);
+	/* delayed_status in bulk mode is 0, so it doesn't need to continue. */
+	if (!opts->streaming_bulk_mult)
+		usb_composite_setup_continue(cdev);
 }
 
 static int
@@ -278,6 +283,7 @@  uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
 	struct usb_composite_dev *cdev = f->config->cdev;
 	struct v4l2_event v4l2_event;
 	struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;
+	struct f_uvc_opts *opts = fi_to_f_uvc_opts(f->fi);
 	int ret;
 
 	uvcg_info(f, "%s(%u, %u)\n", __func__, interface, alt);
@@ -310,49 +316,72 @@  uvc_function_set_alt(struct usb_function *f, unsigned interface, unsigned alt)
 	if (interface != uvc->streaming_intf)
 		return -EINVAL;
 
-	/* TODO
-	if (usb_endpoint_xfer_bulk(&uvc->desc.vs_ep))
-		return alt ? -EINVAL : 0;
-	*/
+	if (opts->streaming_bulk_mult) {
+		switch (alt) {
+		case 0:
+			if (uvc->state != UVC_STATE_CONNECTED)
+				return 0;
 
-	switch (alt) {
-	case 0:
-		if (uvc->state != UVC_STATE_STREAMING)
-			return 0;
+			if (!uvc->video.ep)
+				return -EINVAL;
 
-		if (uvc->video.ep)
+			uvcg_info(f, "reset UVC\n");
 			usb_ep_disable(uvc->video.ep);
 
-		memset(&v4l2_event, 0, sizeof(v4l2_event));
-		v4l2_event.type = UVC_EVENT_STREAMOFF;
-		v4l2_event_queue(&uvc->vdev, &v4l2_event);
-
-		uvc->state = UVC_STATE_CONNECTED;
-		return 0;
+			ret = config_ep_by_speed(f->config->cdev->gadget,
+					&(uvc->func), uvc->video.ep);
+			if (ret)
+				return ret;
+			usb_ep_enable(uvc->video.ep);
 
-	case 1:
-		if (uvc->state != UVC_STATE_CONNECTED)
+			memset(&v4l2_event, 0, sizeof(v4l2_event));
+			v4l2_event.type = UVC_EVENT_STREAMOFF;
+			v4l2_event_queue(&uvc->vdev, &v4l2_event);
 			return 0;
 
-		if (!uvc->video.ep)
+		default:
 			return -EINVAL;
+		}
+	} else {
+		switch (alt) {
+		case 0:
+			if (uvc->state != UVC_STATE_STREAMING)
+				return 0;
+
+			if (uvc->video.ep)
+				usb_ep_disable(uvc->video.ep);
+
+			memset(&v4l2_event, 0, sizeof(v4l2_event));
+			v4l2_event.type = UVC_EVENT_STREAMOFF;
+			v4l2_event_queue(&uvc->vdev, &v4l2_event);
 
-		uvcg_info(f, "reset UVC\n");
-		usb_ep_disable(uvc->video.ep);
+			uvc->state = UVC_STATE_CONNECTED;
+			return 0;
 
-		ret = config_ep_by_speed(f->config->cdev->gadget,
-				&(uvc->func), uvc->video.ep);
-		if (ret)
-			return ret;
-		usb_ep_enable(uvc->video.ep);
+		case 1:
+			if (uvc->state != UVC_STATE_CONNECTED)
+				return 0;
 
-		memset(&v4l2_event, 0, sizeof(v4l2_event));
-		v4l2_event.type = UVC_EVENT_STREAMON;
-		v4l2_event_queue(&uvc->vdev, &v4l2_event);
-		return USB_GADGET_DELAYED_STATUS;
+			if (!uvc->video.ep)
+				return -EINVAL;
 
-	default:
-		return -EINVAL;
+			uvcg_info(f, "reset UVC\n");
+			usb_ep_disable(uvc->video.ep);
+
+			ret = config_ep_by_speed(f->config->cdev->gadget,
+					&(uvc->func), uvc->video.ep);
+			if (ret)
+				return ret;
+			usb_ep_enable(uvc->video.ep);
+
+			memset(&v4l2_event, 0, sizeof(v4l2_event));
+			v4l2_event.type = UVC_EVENT_STREAMON;
+			v4l2_event_queue(&uvc->vdev, &v4l2_event);
+			return USB_GADGET_DELAYED_STATUS;
+
+		default:
+			return -EINVAL;
+		}
 	}
 }
 
@@ -593,62 +622,96 @@  uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 	unsigned int max_packet_size;
 	struct usb_ep *ep;
 	struct f_uvc_opts *opts;
+	int i = 0;
 	int ret = -EINVAL;
 
 	uvcg_info(f, "%s()\n", __func__);
 
 	opts = fi_to_f_uvc_opts(f->fi);
-	/* Sanity check the streaming endpoint module parameters.
-	 */
-	opts->streaming_interval = clamp(opts->streaming_interval, 1U, 16U);
-	opts->streaming_maxpacket = clamp(opts->streaming_maxpacket, 1U, 3072U);
-	opts->streaming_maxburst = min(opts->streaming_maxburst, 15U);
-
-	/* For SS, wMaxPacketSize has to be 1024 if bMaxBurst is not 0 */
-	if (opts->streaming_maxburst &&
-	    (opts->streaming_maxpacket % 1024) != 0) {
-		opts->streaming_maxpacket = roundup(opts->streaming_maxpacket, 1024);
-		uvcg_info(f, "overriding streaming_maxpacket to %d\n",
-			  opts->streaming_maxpacket);
-	}
 
-	/* Fill in the FS/HS/SS Video Streaming specific descriptors from the
-	 * module parameters.
-	 *
-	 * NOTE: We assume that the user knows what they are doing and won't
-	 * give parameters that their UDC doesn't support.
-	 */
-	if (opts->streaming_maxpacket <= 1024) {
-		max_packet_mult = 1;
-		max_packet_size = opts->streaming_maxpacket;
-	} else if (opts->streaming_maxpacket <= 2048) {
-		max_packet_mult = 2;
-		max_packet_size = opts->streaming_maxpacket / 2;
+	/* Handle different transfer mode for stream endpoints */
+	if (opts->streaming_bulk_mult) {
+		uvc_fs_streaming_ep.bmAttributes = USB_ENDPOINT_XFER_BULK;
+		uvc_hs_streaming_ep.bmAttributes = uvc_fs_streaming_ep.bmAttributes;
+		uvc_ss_streaming_ep.bmAttributes = uvc_fs_streaming_ep.bmAttributes;
+
+		opts->streaming_maxburst = min(opts->streaming_maxburst, 15U);
+
+		uvc_fs_streaming_ep.wMaxPacketSize = cpu_to_le16(64);
+		uvc_fs_streaming_ep.bInterval = 0;
+
+		uvc_hs_streaming_ep.wMaxPacketSize = cpu_to_le16(512);
+		uvc_hs_streaming_ep.bInterval = 0;
+
+		uvc_ss_streaming_ep.wMaxPacketSize = cpu_to_le16(1024);
+		uvc_ss_streaming_ep.bInterval = 0;
+
+		uvc_ss_streaming_comp.bmAttributes = 0;
+		uvc_ss_streaming_comp.bMaxBurst = opts->streaming_maxburst;
+		uvc_ss_streaming_comp.wBytesPerInterval = 0;
+
+		uvc->video.max_payload_size = opts->streaming_bulk_mult * 1024;
 	} else {
-		max_packet_mult = 3;
-		max_packet_size = opts->streaming_maxpacket / 3;
-	}
+		uvc_fs_streaming_ep.bmAttributes = USB_ENDPOINT_SYNC_ASYNC
+						| USB_ENDPOINT_XFER_ISOC;
+		uvc_hs_streaming_ep.bmAttributes = uvc_fs_streaming_ep.bmAttributes;
+		uvc_ss_streaming_ep.bmAttributes = uvc_fs_streaming_ep.bmAttributes;
+
+		/* Sanity check the streaming endpoint module parameters.
+		 */
+		opts->streaming_interval = clamp(opts->streaming_interval, 1U, 16U);
+		opts->streaming_maxpacket = clamp(opts->streaming_maxpacket, 1U, 3072U);
+		opts->streaming_maxburst = min(opts->streaming_maxburst, 15U);
+
+		/* For SS, wMaxPacketSize has to be 1024 if bMaxBurst is not 0 */
+		if (opts->streaming_maxburst &&
+			(opts->streaming_maxpacket % 1024) != 0) {
+			opts->streaming_maxpacket = roundup(opts->streaming_maxpacket, 1024);
+			uvcg_info(f, "overriding streaming_maxpacket to %d\n",
+				opts->streaming_maxpacket);
+		}
 
-	uvc_fs_streaming_ep.wMaxPacketSize =
-		cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
-	uvc_fs_streaming_ep.bInterval = opts->streaming_interval;
+		/* Fill in the FS/HS/SS Video Streaming specific descriptors from the
+		 * module parameters.
+		 *
+		 * NOTE: We assume that the user knows what they are doing and won't
+		 * give parameters that their UDC doesn't support.
+		 */
+
+		if (opts->streaming_maxpacket <= 1024) {
+			max_packet_mult = 0;
+			max_packet_size = opts->streaming_maxpacket;
+		} else if (opts->streaming_maxpacket <= 2048) {
+			max_packet_mult = 1;
+			max_packet_size = opts->streaming_maxpacket / 2;
+		} else {
+			max_packet_mult = 2;
+			max_packet_size = opts->streaming_maxpacket / 3;
+		}
 
-	uvc_hs_streaming_ep.wMaxPacketSize =
-		cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
+		uvc_fs_streaming_ep.wMaxPacketSize =
+			cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
+		uvc_fs_streaming_ep.bInterval = opts->streaming_interval;
 
-	/* A high-bandwidth endpoint must specify a bInterval value of 1 */
-	if (max_packet_mult > 1)
-		uvc_hs_streaming_ep.bInterval = 1;
-	else
-		uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
+		uvc_hs_streaming_ep.wMaxPacketSize =
+			cpu_to_le16(max_packet_size | (max_packet_mult << 11));
+		/* A high-bandwidth endpoint must specify a bInterval value of 1 */
+		if (max_packet_mult > 0)
+			uvc_hs_streaming_ep.bInterval = 1;
+		else
+			uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
+
+		uvc_ss_streaming_ep.wMaxPacketSize = cpu_to_le16(max_packet_size);
+		uvc_ss_streaming_ep.bInterval = opts->streaming_interval;
 
-	uvc_ss_streaming_ep.wMaxPacketSize = cpu_to_le16(max_packet_size);
-	uvc_ss_streaming_ep.bInterval = opts->streaming_interval;
-	uvc_ss_streaming_comp.bmAttributes = max_packet_mult - 1;
-	uvc_ss_streaming_comp.bMaxBurst = opts->streaming_maxburst;
-	uvc_ss_streaming_comp.wBytesPerInterval =
-		cpu_to_le16(max_packet_size * max_packet_mult *
-			    (opts->streaming_maxburst + 1));
+		uvc_ss_streaming_comp.bmAttributes = max_packet_mult;
+		uvc_ss_streaming_comp.bMaxBurst = opts->streaming_maxburst;
+		uvc_ss_streaming_comp.wBytesPerInterval =
+			cpu_to_le16(max_packet_size * (max_packet_mult + 1) *
+				(opts->streaming_maxburst + 1));
+
+		uvc->video.max_payload_size = 0;
+	}
 
 	/* Allocate endpoints. */
 	ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
@@ -662,7 +725,7 @@  uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 		ep = usb_ep_autoconfig_ss(cdev->gadget, &uvc_ss_streaming_ep,
 					  &uvc_ss_streaming_comp);
 	else if (gadget_is_dualspeed(cdev->gadget))
-		ep = usb_ep_autoconfig(cdev->gadget, &uvc_hs_streaming_ep);
+		ep = usb_ep_autoconfig_ss(cdev->gadget, &uvc_hs_streaming_ep, NULL);
 	else
 		ep = usb_ep_autoconfig(cdev->gadget, &uvc_fs_streaming_ep);
 
@@ -703,6 +766,28 @@  uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
 	uvc->streaming_intf = ret;
 	opts->streaming_interface = ret;
 
+	/* Handle different transfer mode for descriptors */
+	i = 0;
+	if (opts->streaming_bulk_mult) {
+		uvc_streaming_intf_alt0.bNumEndpoints = 1;
+	} else {
+		uvc_streaming_intf_alt0.bNumEndpoints = 0;
+
+		uvc_fs_streaming[i] = USBDHDR(&uvc_streaming_intf_alt1);
+		uvc_hs_streaming[i] = USBDHDR(&uvc_streaming_intf_alt1);
+		uvc_ss_streaming[i] = USBDHDR(&uvc_streaming_intf_alt1);
+		++i;
+	}
+	uvc_fs_streaming[i] = USBDHDR(&uvc_fs_streaming_ep);
+	uvc_hs_streaming[i] = USBDHDR(&uvc_hs_streaming_ep);
+	uvc_ss_streaming[i] = USBDHDR(&uvc_ss_streaming_ep);
+	++i;
+	uvc_fs_streaming[i] = NULL;
+	uvc_hs_streaming[i] = NULL;
+	uvc_ss_streaming[i] = USBDHDR(&uvc_ss_streaming_comp);
+	++i;
+	uvc_ss_streaming[i] = NULL;
+
 	/* Copy descriptors */
 	f->fs_descriptors = uvc_copy_descriptors(uvc, USB_SPEED_FULL);
 	if (IS_ERR(f->fs_descriptors)) {
@@ -866,6 +951,7 @@  static struct usb_function_instance *uvc_alloc_inst(void)
 
 	opts->streaming_interval = 1;
 	opts->streaming_maxpacket = 1024;
+	opts->streaming_bulk_mult = 0;
 
 	ret = uvcg_attach_configfs(opts);
 	if (ret < 0) {
diff --git a/drivers/usb/gadget/function/u_uvc.h b/drivers/usb/gadget/function/u_uvc.h
index 9a01a7d4f17f..5607a239d55e 100644
--- a/drivers/usb/gadget/function/u_uvc.h
+++ b/drivers/usb/gadget/function/u_uvc.h
@@ -24,6 +24,7 @@  struct f_uvc_opts {
 	unsigned int					streaming_interval;
 	unsigned int					streaming_maxpacket;
 	unsigned int					streaming_maxburst;
+	unsigned int					streaming_bulk_mult;
 
 	unsigned int					control_interface;
 	unsigned int					streaming_interface;
diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c
index 77d64031aa9c..9b08e7b25168 100644
--- a/drivers/usb/gadget/function/uvc_configfs.c
+++ b/drivers/usb/gadget/function/uvc_configfs.c
@@ -2422,6 +2422,7 @@  UVC_ATTR(f_uvc_opts_, cname, cname)
 UVCG_OPTS_ATTR(streaming_interval, streaming_interval, 16);
 UVCG_OPTS_ATTR(streaming_maxpacket, streaming_maxpacket, 3072);
 UVCG_OPTS_ATTR(streaming_maxburst, streaming_maxburst, 15);
+UVCG_OPTS_ATTR(streaming_bulk_mult, streaming_bulk_mult, 0x3fffffU);
 
 #undef UVCG_OPTS_ATTR
 
@@ -2429,6 +2430,7 @@  static struct configfs_attribute *uvc_attrs[] = {
 	&f_uvc_opts_attr_streaming_interval,
 	&f_uvc_opts_attr_streaming_maxpacket,
 	&f_uvc_opts_attr_streaming_maxburst,
+	&f_uvc_opts_attr_streaming_bulk_mult,
 	NULL,
 };
 
diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c
index 2cda982f3765..98d0e933b5e1 100644
--- a/drivers/usb/gadget/function/uvc_queue.c
+++ b/drivers/usb/gadget/function/uvc_queue.c
@@ -135,7 +135,9 @@  int uvcg_queue_init(struct uvc_video_queue *queue, struct device *dev, enum v4l2
 	queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
 	queue->queue.ops = &uvc_queue_qops;
 	queue->queue.lock = lock;
-	if (cdev->gadget->sg_supported) {
+
+	/* UDC supports scatter gather and transfer mode isn't bulk. */
+	if (cdev->gadget->sg_supported && !video->max_payload_size) {
 		queue->queue.mem_ops = &vb2_dma_sg_memops;
 		queue->use_sg = 1;
 	} else {
diff --git a/drivers/usb/gadget/function/uvc_v4l2.c b/drivers/usb/gadget/function/uvc_v4l2.c
index a2c78690c5c2..767f1a2ace04 100644
--- a/drivers/usb/gadget/function/uvc_v4l2.c
+++ b/drivers/usb/gadget/function/uvc_v4l2.c
@@ -119,6 +119,14 @@  uvc_v4l2_set_format(struct file *file, void *fh, struct v4l2_format *fmt)
 	bpl = format->bpp * fmt->fmt.pix.width / 8;
 	imagesize = bpl ? bpl * fmt->fmt.pix.height : fmt->fmt.pix.sizeimage;
 
+	/*
+	 * Bulk mode only allocates memory once, so user should give the
+	 * maximum image size in all formats and kernel should not decrease
+	 * the imagesize.
+	 */
+	if (video->max_payload_size && imagesize < fmt->fmt.pix.sizeimage)
+		imagesize = fmt->fmt.pix.sizeimage;
+
 	video->fcc = format->fcc;
 	video->bpp = format->bpp;
 	video->width = fmt->fmt.pix.width;