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. Default the feature off since there are transmission problems with at least one controller, dwc3.

Fixes: e81e7f9a0eb9 ("usb: gadget: uvc: add scatter gather support") Cc: stable@vger.kernel.org Signed-off-by: Dan Vacura w36195@motorola.com --- V1 -> V2: - no change, new patch in series

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 75f524c83996..965cf5b48094 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->video.req_int_skip_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 = 0; + opts->sg_supported = 0; 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 fc65f8e73732..b11b1e4cfed6 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