From ffc79982fce692570c017fc914cb639b3e76c173 Mon Sep 17 00:00:00 2001
From: Brad Stein <Brad.Stein@gmail.com>
Date: Fri, 23 Jan 2026 03:04:34 -0300
Subject: [PATCH] kernel: log uvc prep request sizing

---
 scripts/kernel/uvc-debug.patch | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/scripts/kernel/uvc-debug.patch b/scripts/kernel/uvc-debug.patch
index 0c5d266..ce2416e 100644
--- a/scripts/kernel/uvc-debug.patch
+++ b/scripts/kernel/uvc-debug.patch
@@ -45,3 +45,25 @@
  	/*
  	 * Safe to access request related fields without req_lock because
  	 * this is the only thread currently active, and no other
+
+@@ -510,6 +532,19 @@
+ 	if (req_size > max_req_size) {
+ 		/* The prepared interval length and expected buffer size
+ 		 * is not possible to stream with the currently configured
+ 		 * isoc bandwidth. Fallback to the maximum.
+ 		 */
+ 		req_size = max_req_size;
+ 	}
+ 	video->req_size = req_size;
+
+ 	if (!req_size || !video->max_payload_size || !video->imagesize || !nreq) {
+ 		uvcg_info(&uvc->func,
+ 			"Video prep requests: imagesize=%u interval=%u interval_dur=%u nreq=%u header=%u req_size=%u max_req=%u max_payload=%u ep_maxpacket=%u maxburst=%u mult=%u bInterval=%u speed=%u\n",
+ 			video->imagesize, video->interval, interval_duration, nreq,
+ 			header_size, req_size, max_req_size,
+ 			video->max_payload_size, video->ep->maxpacket,
+ 			video->ep->maxburst, video->ep->mult,
+ 			video->ep->desc->bInterval, cdev->gadget->speed);
+ 	}
+
+ 	/* We need to compensate the amount of requests to be