uvc: read fifo caps from debugfs

scripts/daemon/lesavka-core.sh

@@ -131,12 +131,50 @@ uvc_fifo_min() {
         END { if (min != "") print min }'
 }
 
+uvc_fifo_min_debugfs() {
+    local path="$1"
+    awk -F': ' '/^g_tx_fifo_size\\[/{print $2}' "$path" 2>/dev/null | awk '
+        $1 > 0 { if (min == "" || $1 < min) min = $1 }
+        END { if (min != "") print min }'
+}
+
+uvc_fifo_np_debugfs() {
+    local path="$1"
+    awk -F': ' '/^g_np_tx_fifo_size/{print $2; exit}' "$path" 2>/dev/null
+}
+
 compute_uvc_payload_cap() {
     UVC_PAYLOAD_CAP=""
     UVC_PAYLOAD_SRC=""
     UVC_PAYLOAD_PCT=""
     UVC_FIFO_PERIODIC="$(uvc_fifo_min /sys/module/dwc2/parameters/g_tx_fifo_size)"
     UVC_FIFO_NP="$(uvc_fifo_min /sys/module/dwc2/parameters/g_np_tx_fifo_size)"
+    UVC_FIFO_SRC_PERIODIC=""
+    UVC_FIFO_SRC_NP=""
+    if [[ -n $UVC_FIFO_PERIODIC ]]; then
+        UVC_FIFO_SRC_PERIODIC="dwc2.params"
+    fi
+    if [[ -n $UVC_FIFO_NP ]]; then
+        UVC_FIFO_SRC_NP="dwc2.params"
+    fi
+    UVC_UDC="$(ls /sys/class/udc 2>/dev/null | head -n1 || true)"
+    if [[ -n $UVC_UDC ]]; then
+        local params="/sys/kernel/debug/usb/$UVC_UDC/params"
+        if [[ -r $params ]]; then
+            if [[ -z $UVC_FIFO_PERIODIC ]]; then
+                UVC_FIFO_PERIODIC="$(uvc_fifo_min_debugfs "$params")"
+                if [[ -n $UVC_FIFO_PERIODIC ]]; then
+                    UVC_FIFO_SRC_PERIODIC="debugfs.params"
+                fi
+            fi
+            if [[ -z $UVC_FIFO_NP ]]; then
+                UVC_FIFO_NP="$(uvc_fifo_np_debugfs "$params")"
+                if [[ -n $UVC_FIFO_NP ]]; then
+                    UVC_FIFO_SRC_NP="debugfs.params"
+                fi
+            fi
+        fi
+    fi
 
     if [[ -n ${LESAVKA_UVC_MAXPAYLOAD_LIMIT:-} ]]; then
         UVC_PAYLOAD_CAP="${LESAVKA_UVC_MAXPAYLOAD_LIMIT}"
@@ -149,18 +187,18 @@ compute_uvc_payload_cap() {
     if [[ -n $UVC_BULK ]]; then
         if [[ -n $UVC_FIFO_NP ]]; then
             chosen="$UVC_FIFO_NP"
-            UVC_PAYLOAD_SRC="dwc2.g_np_tx_fifo_size"
+            UVC_PAYLOAD_SRC="${UVC_FIFO_SRC_NP:-dwc2.g_np_tx_fifo_size}"
         elif [[ -n $UVC_FIFO_PERIODIC ]]; then
             chosen="$UVC_FIFO_PERIODIC"
-            UVC_PAYLOAD_SRC="dwc2.g_tx_fifo_size"
+            UVC_PAYLOAD_SRC="${UVC_FIFO_SRC_PERIODIC:-dwc2.g_tx_fifo_size}"
         fi
     else
         if [[ -n $UVC_FIFO_PERIODIC ]]; then
             chosen="$UVC_FIFO_PERIODIC"
-            UVC_PAYLOAD_SRC="dwc2.g_tx_fifo_size"
+            UVC_PAYLOAD_SRC="${UVC_FIFO_SRC_PERIODIC:-dwc2.g_tx_fifo_size}"
         elif [[ -n $UVC_FIFO_NP ]]; then
             chosen="$UVC_FIFO_NP"
-            UVC_PAYLOAD_SRC="dwc2.g_np_tx_fifo_size"
+            UVC_PAYLOAD_SRC="${UVC_FIFO_SRC_NP:-dwc2.g_np_tx_fifo_size}"
         fi
     fi
 
@@ -181,7 +219,7 @@ compute_uvc_payload_cap() {
 
 compute_uvc_payload_cap
 if [[ -n $UVC_PAYLOAD_CAP && $UVC_PAYLOAD_CAP -gt 0 ]]; then
-    log "UVC fifo periodic=${UVC_FIFO_PERIODIC:-?} np=${UVC_FIFO_NP:-?} cap=${UVC_PAYLOAD_CAP}B pct=${UVC_PAYLOAD_PCT:-?} src=${UVC_PAYLOAD_SRC:-?}"
+    log "UVC fifo periodic=${UVC_FIFO_PERIODIC:-?} np=${UVC_FIFO_NP:-?} cap=${UVC_PAYLOAD_CAP}B pct=${UVC_PAYLOAD_PCT:-?} src=${UVC_PAYLOAD_SRC:-?} udc=${UVC_UDC:-?}"
     if ((UVC_MAXPACKET > UVC_PAYLOAD_CAP)); then
         log "clamping UVC maxpacket $UVC_MAXPACKET -> $UVC_PAYLOAD_CAP"
         UVC_MAXPACKET=$UVC_PAYLOAD_CAP

server/src/bin/lesavka-uvc.rs

@@ -807,21 +807,35 @@ fn compute_payload_cap(bulk: bool) -> Option<PayloadCap> {
         });
     }
 
-    let periodic_dw = read_fifo_min("/sys/module/dwc2/parameters/g_tx_fifo_size");
+    let mut periodic = read_fifo_min("/sys/module/dwc2/parameters/g_tx_fifo_size")
-    let non_periodic_dw = read_fifo_min("/sys/module/dwc2/parameters/g_np_tx_fifo_size");
+        .map(|v| (v, "dwc2.params"));
+    let mut non_periodic = read_fifo_min("/sys/module/dwc2/parameters/g_np_tx_fifo_size")
+        .map(|v| (v, "dwc2.params"));
+    if periodic.is_none() || non_periodic.is_none() {
+        if let Some((p, np)) = read_debugfs_fifos() {
+            if periodic.is_none() {
+                periodic = p.map(|v| (v, "debugfs.params"));
+            }
+            if non_periodic.is_none() {
+                non_periodic = np.map(|v| (v, "debugfs.params"));
+            }
+        }
+    }
+    let periodic_dw = periodic.map(|(v, _)| v);
+    let non_periodic_dw = non_periodic.map(|(v, _)| v);
 
     let (fifo_dw, source) = if bulk {
-        if let Some(np) = non_periodic_dw {
+        if let Some((np, src)) = non_periodic {
-            (np, "dwc2.g_np_tx_fifo_size")
+            (np, src)
-        } else if let Some(p) = periodic_dw {
+        } else if let Some((p, src)) = periodic {
-            (p, "dwc2.g_tx_fifo_size")
+            (p, src)
         } else {
             return None;
         }
-    } else if let Some(p) = periodic_dw {
+    } else if let Some((p, src)) = periodic {
-        (p, "dwc2.g_tx_fifo_size")
+        (p, src)
-    } else if let Some(np) = non_periodic_dw {
+    } else if let Some((np, src)) = non_periodic {
-        (np, "dwc2.g_np_tx_fifo_size")
+        (np, src)
     } else {
         return None;
     };
@@ -855,6 +869,36 @@ fn read_fifo_min(path: &str) -> Option<u32> {
         .min()
 }
 
+fn read_debugfs_fifos() -> Option<(Option<u32>, Option<u32>)> {
+    let udc = std::fs::read_dir("/sys/class/udc")
+        .ok()?
+        .filter_map(|e| e.ok())
+        .filter_map(|e| e.file_name().into_string().ok())
+        .next()?;
+    let path = format!("/sys/kernel/debug/usb/{udc}/params");
+    let text = std::fs::read_to_string(path).ok()?;
+    let mut periodic: Option<u32> = None;
+    let mut non_periodic: Option<u32> = None;
+    for line in text.lines() {
+        let mut parts = line.splitn(2, ':');
+        let key = parts.next()?.trim();
+        let val = parts.next()?.trim().parse::<u32>().ok()?;
+        if key == "g_np_tx_fifo_size" {
+            non_periodic = Some(val);
+        } else if key.starts_with("g_tx_fifo_size[") && val > 0 {
+            periodic = Some(match periodic {
+                Some(prev) => prev.min(val),
+                None => val,
+            });
+        }
+    }
+    if periodic.is_none() && non_periodic.is_none() {
+        None
+    } else {
+        Some((periodic, non_periodic))
+    }
+}
+
 const IOC_NRBITS: u8 = 8;
 const IOC_TYPEBITS: u8 = 8;
 const IOC_SIZEBITS: u8 = 14;