[PATCH v2 1/3] usb: gadget: uvc: make interrupt skip logic configurable
From: Dan Vacura
Date: Tue Oct 11 2022 - 14:35:35 EST
Some UDC hw may not support skipping interrupts, but still support the
request. Allow the interrupt frequency to be configurable to the user.
Default to not skip interrupts, a value of 0. This fixes a smmu panic
that is occurring on dwc3 hw.
Fixes: fc78941d8169 ("usb: gadget: uvc: decrease the interrupt load to a quarter")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Vacura <w36195@xxxxxxxxxxxx>
---
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 | 3 +++
drivers/usb/gadget/function/u_uvc.h | 1 +
drivers/usb/gadget/function/uvc.h | 1 +
drivers/usb/gadget/function/uvc_configfs.c | 2 ++
drivers/usb/gadget/function/uvc_queue.c | 6 ++++++
drivers/usb/gadget/function/uvc_video.c | 3 ++-
8 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/Documentation/ABI/testing/configfs-usb-gadget-uvc b/Documentation/ABI/testing/configfs-usb-gadget-uvc
index 611b23e6488d..5dfaa3f7f6a4 100644
--- a/Documentation/ABI/testing/configfs-usb-gadget-uvc
+++ b/Documentation/ABI/testing/configfs-usb-gadget-uvc
@@ -8,6 +8,7 @@ Description: UVC function directory
streaming_maxpacket 1..1023 (fs), 1..3072 (hs/ss)
streaming_interval 1..16
function_name string [32]
+ req_int_skip_div unsigned int
=================== =============================
What: /config/usb-gadget/gadget/functions/uvc.name/control
diff --git a/Documentation/usb/gadget-testing.rst b/Documentation/usb/gadget-testing.rst
index 2278c9ffb74a..f9b5a09be1f4 100644
--- a/Documentation/usb/gadget-testing.rst
+++ b/Documentation/usb/gadget-testing.rst
@@ -794,6 +794,8 @@ The uvc function provides these attributes in its function directory:
sending or receiving when this configuration is
selected
function_name name of the interface
+ req_int_skip_div divisor of total requests to aid in calculating
+ interrupt frequency, 0 indicates all interrupt
=================== ================================================
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 6e196e06181e..75f524c83996 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -655,6 +655,8 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
cpu_to_le16(max_packet_size * max_packet_mult *
(opts->streaming_maxburst + 1));
+ uvc->video.req_int_skip_div = opts->req_int_skip_div;
+
/* Allocate endpoints. */
ep = usb_ep_autoconfig(cdev->gadget, &uvc_control_ep);
if (!ep) {
@@ -872,6 +874,7 @@ static struct usb_function_instance *uvc_alloc_inst(void)
opts->streaming_interval = 1;
opts->streaming_maxpacket = 1024;
+ opts->req_int_skip_div = 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 24b8681b0d6f..6f73bd5638ed 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 req_int_skip_div;
unsigned int control_interface;
unsigned int streaming_interface;
diff --git a/drivers/usb/gadget/function/uvc.h b/drivers/usb/gadget/function/uvc.h
index 40226b1f7e14..53175cd564e5 100644
--- a/drivers/usb/gadget/function/uvc.h
+++ b/drivers/usb/gadget/function/uvc.h
@@ -107,6 +107,7 @@ struct uvc_video {
spinlock_t req_lock;
unsigned int req_int_count;
+ unsigned int req_int_skip_div;
void (*encode) (struct usb_request *req, struct uvc_video *video,
struct uvc_buffer *buf);
diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c
index 4303a3283ba0..419e926ab57e 100644
--- a/drivers/usb/gadget/function/uvc_configfs.c
+++ b/drivers/usb/gadget/function/uvc_configfs.c
@@ -2350,6 +2350,7 @@ 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(req_int_skip_div, req_int_skip_div, UINT_MAX);
#undef UVCG_OPTS_ATTR
@@ -2399,6 +2400,7 @@ 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_req_int_skip_div,
&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 ec500ee499ee..872d545838ee 100644
--- a/drivers/usb/gadget/function/uvc_queue.c
+++ b/drivers/usb/gadget/function/uvc_queue.c
@@ -63,6 +63,12 @@ static int uvc_queue_setup(struct vb2_queue *vq,
*/
nreq = DIV_ROUND_UP(DIV_ROUND_UP(sizes[0], 2), req_size);
nreq = clamp(nreq, 4U, 64U);
+ if (0 == video->req_int_skip_div) {
+ video->req_int_skip_div = nreq;
+ } else {
+ video->req_int_skip_div =
+ min_t(unsigned int, nreq, video->req_int_skip_div);
+ }
video->uvc_num_requests = nreq;
return 0;
diff --git a/drivers/usb/gadget/function/uvc_video.c b/drivers/usb/gadget/function/uvc_video.c
index bb037fcc90e6..241df42ce0ae 100644
--- a/drivers/usb/gadget/function/uvc_video.c
+++ b/drivers/usb/gadget/function/uvc_video.c
@@ -413,7 +413,8 @@ static void uvcg_video_pump(struct work_struct *work)
if (list_empty(&video->req_free) ||
buf->state == UVC_BUF_STATE_DONE ||
!(video->req_int_count %
- DIV_ROUND_UP(video->uvc_num_requests, 4))) {
+ DIV_ROUND_UP(video->uvc_num_requests,
+ video->req_int_skip_div))) {
video->req_int_count = 0;
req->no_interrupt = 0;
} else {
--
2.34.1