[PATCH v3 6/6] usb: gadget: uvc: add configfs option for sg support
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STALE956d
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From: Dan Vacura <hidden>
Date: 2022-10-17 20:56:12
Also in:
linux-usb, lkml
Subsystem:
documentation, the rest, usb subsystem, usb webcam gadget · Maintainers:
Jonathan Corbet, Linus Torvalds, Greg Kroah-Hartman
Revision v3 of 2 in this series.
Revisions (2)
- v3 current
- v4 [diff vs current]
The scatter gather support doesn't appear to work well with some UDC hw. Add the ability to turn on the feature depending on the controller in use. Signed-off-by: Dan Vacura <redacted> --- V1 -> V2: - no change, new patch in serie V2 -> V3: - default on, same as baseline Documentation/ABI/testing/configfs-usb-gadget-uvc | 1 + Documentation/usb/gadget-testing.rst | 2 ++ drivers/usb/gadget/function/f_uvc.c | 2 ++ drivers/usb/gadget/function/u_uvc.h | 1 + drivers/usb/gadget/function/uvc_configfs.c | 2 ++ drivers/usb/gadget/function/uvc_queue.c | 4 ++-- 6 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uvc b/Documentation/ABI/testing/configfs-usb-gadget-uvc
index 5dfaa3f7f6a4..839a75fc28ee 100644
--- a/Documentation/ABI/testing/configfs-usb-gadget-uvc
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uvc@@ -9,6 +9,7 @@ Description: UVC function directory streaming_interval 1..16 function_name string [32] req_int_skip_div unsigned int + sg_supported 0..1 =================== ============================= What: /config/usb-gadget/gadget/functions/uvc.name/control
diff --git a/Documentation/usb/gadget-testing.rst b/Documentation/usb/gadget-testing.rst
index f9b5a09be1f4..8e3072d6a590 100644
--- a/Documentation/usb/gadget-testing.rst
+++ b/Documentation/usb/gadget-testing.rst@@ -796,6 +796,8 @@ The uvc function provides these attributes in its function directory: function_name name of the interface req_int_skip_div divisor of total requests to aid in calculating interrupt frequency, 0 indicates all interrupt + sg_supported allow for scatter gather to be used if the UDC + hw supports it =================== ================================================ 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 e40ca26b9c55..d08ebe3ffeb2 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c@@ -656,6 +656,7 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f) (opts->streaming_maxburst + 1)); uvc->config_skip_int_div = opts->req_int_skip_div; + uvc->video.queue.use_sg = opts->sg_supported; /* Allocate endpoints. */ ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
@@ -875,6 +876,7 @@ static struct usb_function_instance *uvc_alloc_inst(void) opts->streaming_interval = 1; opts->streaming_maxpacket = 1024; opts->req_int_skip_div = 4; + opts->sg_supported = 1; snprintf(opts->function_name, sizeof(opts->function_name), "UVC Camera"); ret = uvcg_attach_configfs(opts);
diff --git a/drivers/usb/gadget/function/u_uvc.h b/drivers/usb/gadget/function/u_uvc.h
index 6f73bd5638ed..5ccced629925 100644
--- a/drivers/usb/gadget/function/u_uvc.h
+++ b/drivers/usb/gadget/function/u_uvc.h@@ -25,6 +25,7 @@ struct f_uvc_opts { unsigned int streaming_maxpacket; unsigned int streaming_maxburst; unsigned int req_int_skip_div; + unsigned int sg_supported; 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 419e926ab57e..3784c0e02d01 100644
--- a/drivers/usb/gadget/function/uvc_configfs.c
+++ b/drivers/usb/gadget/function/uvc_configfs.c@@ -2351,6 +2351,7 @@ 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(req_int_skip_div, req_int_skip_div, UINT_MAX); +UVCG_OPTS_ATTR(sg_supported, sg_supported, 1); #undef UVCG_OPTS_ATTR
@@ -2401,6 +2402,7 @@ static struct configfs_attribute *uvc_attrs[] = { &f_uvc_opts_attr_streaming_maxpacket, &f_uvc_opts_attr_streaming_maxburst, &f_uvc_opts_attr_req_int_skip_div, + &f_uvc_opts_attr_sg_supported, &f_uvc_opts_string_attr_function_name, NULL, };
diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c
index 02559906a55a..3c7aa5c4bba2 100644
--- a/drivers/usb/gadget/function/uvc_queue.c
+++ b/drivers/usb/gadget/function/uvc_queue.c@@ -149,11 +149,11 @@ 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) { + if (queue->use_sg && cdev->gadget->sg_supported) { queue->queue.mem_ops = &vb2_dma_sg_memops; - queue->use_sg = 1; } else { queue->queue.mem_ops = &vb2_vmalloc_memops; + queue->use_sg = false; } queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY
--
2.34.1