Volume switcher: USB link speed indicator

vdavid · vdavid · commit 637b152e5206 · 2026-05-15T16:05:39.000+02:00
- Color-coded dot on the volume chip and on each dropdown row for MTP volumes, mirroring the SMB indicator placement and tooltip pattern.
- Five tiers: USB 1.0 low / 1.1 full / 2.0 / 3.2 Gen 1 / 3.2 Gen 2 → red, orange, yellow, light green, dark green. Dark green is `--color-allow`, same shade as SMB direct.
- Tooltip shows the generation name, theoretical max MB/s, and a "Negotiated for this cable, port, and device" line on a second row.
- Backend: `usb_speed: Option&lt;UsbSpeed&gt;` plumbed from `mtp-rs` through MTP discovery and `MtpConnectionManager::connect` into `LocationInfo`. New `crate::usb_speed` module mirrors `mtp_rs::UsbSpeed` cross-platform so macOS, Linux, and stub volumes share one shape.
- Bug: the `commands/volumes.rs` and `volume_broadcast.rs` MTP enrichment paths are duplicated; the IPC variant hardcoded `usb_speed: None`, leaving the dot missing on bootstrap until a `volumes-changed` push refreshed it. Both call sites now read from `ConnectedDeviceInfo`. Documented in `volumes/CLAUDE.md` so future agents catch the two-site contract.
- Bumped `mtp-rs` to 0.14.0.
- Docs: new "USB link-speed indicator (MTP)" section in `navigation/CLAUDE.md`; `mtp/CLAUDE.md` notes the field; `volumes/CLAUDE.md` gains the two-site `append_mtp_volumes` gotcha.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/apps/desktop/src-tauri/Cargo.toml b/apps/desktop/src-tauri/Cargo.toml
@@ -161,7 +161,7 @@ mime_guess = "2"
 
 [target.'cfg(any(target_os = "macos", target_os = "linux"))'.dependencies]
 # MTP (Android device) support via pure Rust implementation
-mtp-rs = "0.13.2"
+mtp-rs = "0.14.0"
 # USB hotplug detection for MTP device watcher
 nusb = "0.2.3"
 bytes = "1"
diff --git a/apps/desktop/src-tauri/src/commands/volumes.rs b/apps/desktop/src-tauri/src/commands/volumes.rs
@@ -104,6 +104,7 @@ pub async fn resolve_path_volume(path: String) -> PathVolumeResolution {
                 supports_trash: false,
                 is_read_only: false,
                 smb_connection_state: None,
+                usb_speed: None,
             }),
             timed_out: false,
         };
@@ -163,6 +164,7 @@ async fn append_mtp_volumes(volumes: &mut Vec<VolumeInfo>) {
                 fs_type: Some("mtp".to_string()),
                 supports_trash: false,
                 smb_connection_state: None,
+                usb_speed: device.device.usb_speed,
             });
         }
     }
diff --git a/apps/desktop/src-tauri/src/commands/volumes_linux.rs b/apps/desktop/src-tauri/src/commands/volumes_linux.rs
@@ -78,6 +78,7 @@ pub async fn resolve_path_volume(path: String) -> PathVolumeResolution {
                 supports_trash: false,
                 is_read_only: false,
                 smb_connection_state: None,
+                usb_speed: None,
             }),
             timed_out: false,
         };
@@ -138,6 +139,7 @@ async fn append_mtp_volumes(volumes: &mut Vec<VolumeInfo>) {
                 fs_type: Some("mtp".to_string()),
                 supports_trash: false,
                 smb_connection_state: None,
+                usb_speed: device.device.usb_speed,
             });
         }
     }
diff --git a/apps/desktop/src-tauri/src/lib.rs b/apps/desktop/src-tauri/src/lib.rs
@@ -127,6 +127,7 @@ pub mod test_mode;
 mod text_size;
 #[cfg(target_os = "macos")]
 mod updater;
+mod usb_speed;
 mod volume_broadcast;
 #[cfg(target_os = "macos")]
 mod volumes;
diff --git a/apps/desktop/src-tauri/src/mtp/CLAUDE.md b/apps/desktop/src-tauri/src/mtp/CLAUDE.md
@@ -9,11 +9,11 @@ On Linux, users may need udev rules for USB device permissions (see `resources/9
 | File | Purpose |
 |------|---------|
 | `mod.rs` | Re-exports public surface; module-level doc |
-| `types.rs` | `MtpDeviceInfo`, `MtpStorageInfo`: camelCase JSON via `serde(rename_all)` |
+| `types.rs` | `MtpDeviceInfo`, `MtpStorageInfo`: camelCase JSON via `serde(rename_all)`. `MtpDeviceInfo::usb_speed` mirrors `mtp_rs::UsbSpeed` via the shared `crate::usb_speed::UsbSpeed` (also surfaced on `LocationInfo` for MTP volumes so the volume switcher can show a colored dot). |
 | `discovery.rs` | `list_mtp_devices()` via `mtp_rs::MtpDevice::list_devices()`; device IDs formatted as `"mtp-{location_id}"` |
 | `watcher.rs` | `start_mtp_watcher()`: nusb hotplug watcher; 500 ms delay on connect before re-checking; auto-connects detected devices via `MtpConnectionManager::connect()` and auto-disconnects removed ones |
 | `macos_workaround.rs` | macOS-only (`#[cfg(target_os = "macos")]`). Auto-suppresses `ptpcamerad` via `launchctl disable` + `pkill`; restores on disconnect/exit; `ensure_ptpcamerad_enabled()` on startup for crash recovery. Falls back to manual `PTPCAMERAD_WORKAROUND_COMMAND` dialog if suppression fails |
-| `connection/mod.rs` | `MtpConnectionManager` singleton (`LazyLock`); `DeviceEntry` map; `connect()` (idempotent, probes write capability, registers `MtpVolume`); `disconnect()` |
+| `connection/mod.rs` | `MtpConnectionManager` singleton (`LazyLock`); `DeviceEntry` map; `connect()` (idempotent, probes write capability, registers `MtpVolume`, re-runs `MtpDevice::list_devices()` once to fetch the negotiated USB link speed since the open `MtpDevice` doesn't expose it); `disconnect()` |
 | `connection/cache.rs` | `PathHandleCache` (path → MTP object handle), `ListingCache` (5 s TTL), `EventDebouncer` (500 ms per device) |
 | `connection/errors.rs` | `MtpConnectionError` enum with typed variants and `map_mtp_error()` from `mtp_rs::Error` |
 | `connection/event_loop.rs` | Background tokio task per device: polls `device.next_event()`, computes diffs, emits `directory-diff` events using the unified diff system |
diff --git a/apps/desktop/src-tauri/src/mtp/connection/mod.rs b/apps/desktop/src-tauri/src/mtp/connection/mod.rs
@@ -249,6 +249,15 @@ impl MtpConnectionManager {
 
         // Get device info
         let mtp_info = device.device_info();
+
+        // Speed isn't exposed by the open MTP session — read it from a fresh USB
+        // enumeration. `list_devices()` is a cheap syscall (no device open).
+        let usb_speed = MtpDevice::list_devices()
+            .ok()
+            .and_then(|devs| devs.into_iter().find(|d| d.location_id == location_id))
+            .and_then(|d| d.speed)
+            .map(crate::mtp::types::UsbSpeed::from);
+
         let device_info = MtpDeviceInfo {
             id: device_id.to_string(),
             location_id,
@@ -269,6 +278,7 @@ impl MtpConnectionManager {
             } else {
                 Some(mtp_info.serial_number.clone())
             },
+            usb_speed,
         };
 
         debug!(
@@ -1007,6 +1017,7 @@ mod tests {
                 manufacturer: Some("Google".to_string()),
                 product: Some("Pixel 8".to_string()),
                 serial_number: None,
+                usb_speed: None,
             },
             storages: vec![MtpStorageInfo {
                 id: 65537,
diff --git a/apps/desktop/src-tauri/src/mtp/discovery.rs b/apps/desktop/src-tauri/src/mtp/discovery.rs
@@ -41,6 +41,7 @@ pub fn list_mtp_devices() -> Vec<MtpDeviceInfo> {
                         manufacturer: d.manufacturer,
                         product: d.product,
                         serial_number: d.serial_number,
+                        usb_speed: d.speed.map(Into::into),
                     }
                 })
                 .collect()
diff --git a/apps/desktop/src-tauri/src/mtp/types.rs b/apps/desktop/src-tauri/src/mtp/types.rs
@@ -4,6 +4,8 @@
 
 use serde::Serialize;
 
+pub use crate::usb_speed::UsbSpeed;
+
 /// Information about a connected MTP device.
 ///
 /// This represents a device detected via USB, before opening an MTP session.
@@ -25,6 +27,9 @@ pub struct MtpDeviceInfo {
     pub manufacturer: Option<String>,
     pub product: Option<String>,
     pub serial_number: Option<String>,
+    /// Negotiated USB link speed (slowest of host port, cable, device).
+    /// `None` if the OS doesn't report it.
+    pub usb_speed: Option<UsbSpeed>,
 }
 
 /// Information about a storage area on an MTP device.
@@ -64,13 +69,15 @@ mod tests {
             manufacturer: Some("Google".to_string()),
             product: Some("Pixel".to_string()),
             serial_number: None,
+            usb_speed: Some(UsbSpeed::Super),
         };
         let json = serde_json::to_string(&device).unwrap();
         assert!(json.contains("\"vendorId\":"));
         assert!(json.contains("\"productId\":"));
         assert!(json.contains("\"locationId\":"));
         // serialNumber serializes as explicit null (no longer omitted)
         assert!(json.contains("\"serialNumber\":null"));
+        assert!(json.contains("\"usbSpeed\":\"super\""));
     }
 
     #[test]
diff --git a/apps/desktop/src-tauri/src/stubs/volumes.rs b/apps/desktop/src-tauri/src/stubs/volumes.rs
@@ -35,6 +35,8 @@ pub struct VolumeInfo {
     pub is_read_only: bool,
     /// SMB connection state indicator. Always `None` on stub platforms.
     pub smb_connection_state: Option<String>,
+    /// Negotiated USB link speed. Always `None` on stub platforms (no MTP).
+    pub usb_speed: Option<crate::usb_speed::UsbSpeed>,
 }
 
 /// Information about volume space.
@@ -75,6 +77,7 @@ pub fn list_volumes() -> Vec<VolumeInfo> {
                 supports_trash: true,
                 is_read_only: false,
                 smb_connection_state: None,
+                usb_speed: None,
             });
         }
     }
@@ -91,6 +94,7 @@ pub fn list_volumes() -> Vec<VolumeInfo> {
         supports_trash: true,
         is_read_only: false,
         smb_connection_state: None,
+        usb_speed: None,
     });
 
     // Add home directory
@@ -105,6 +109,7 @@ pub fn list_volumes() -> Vec<VolumeInfo> {
         supports_trash: true,
         is_read_only: false,
         smb_connection_state: None,
+        usb_speed: None,
     });
 
     locations
diff --git a/apps/desktop/src-tauri/src/usb_speed.rs b/apps/desktop/src-tauri/src/usb_speed.rs
@@ -0,0 +1,37 @@
+//! Negotiated USB link speed exposed to the frontend.
+//!
+//! Cross-platform mirror of `mtp_rs::UsbSpeed` so the shared `LocationInfo` /
+//! `VolumeInfo` shape stays identical across macOS, Linux, and stub platforms.
+//! Producer side (MTP discovery) lives behind `#[cfg(any(target_os = "macos",
+//! target_os = "linux"))]`; everything else carries `None`.
+
+use serde::{Deserialize, Serialize};
+
+/// Negotiated USB link speed (slowest of host port, cable, device).
+#[derive(Debug, Clone, Copy, Serialize, Deserialize, specta::Type)]
+#[serde(rename_all = "snake_case")]
+pub enum UsbSpeed {
+    /// USB 1.0 low-speed (1.5 Mbit/s).
+    Low,
+    /// USB 1.1 full-speed (12 Mbit/s).
+    Full,
+    /// USB 2.0 high-speed (480 Mbit/s).
+    High,
+    /// USB 3.2 Gen 1 / formerly USB 3.0 (5 Gbit/s).
+    Super,
+    /// USB 3.2 Gen 2 / formerly USB 3.1 Gen 2 (10 Gbit/s).
+    SuperPlus,
+}
+
+#[cfg(any(target_os = "macos", target_os = "linux"))]
+impl From<mtp_rs::UsbSpeed> for UsbSpeed {
+    fn from(s: mtp_rs::UsbSpeed) -> Self {
+        match s {
+            mtp_rs::UsbSpeed::Low => UsbSpeed::Low,
+            mtp_rs::UsbSpeed::Full => UsbSpeed::Full,
+            mtp_rs::UsbSpeed::High => UsbSpeed::High,
+            mtp_rs::UsbSpeed::Super => UsbSpeed::Super,
+            mtp_rs::UsbSpeed::SuperPlus => UsbSpeed::SuperPlus,
+        }
+    }
+}
diff --git a/apps/desktop/src-tauri/src/volume_broadcast.rs b/apps/desktop/src-tauri/src/volume_broadcast.rs
@@ -222,6 +222,7 @@ async fn append_mtp_volumes(volumes: &mut Vec<LocationInfo>) {
                 fs_type: Some("mtp".to_string()),
                 supports_trash: false,
                 smb_connection_state: None,
+                usb_speed: device.device.usb_speed,
             });
         }
     }
diff --git a/apps/desktop/src-tauri/src/volumes/CLAUDE.md b/apps/desktop/src-tauri/src/volumes/CLAUDE.md
@@ -70,6 +70,9 @@ The local `get_icon_for_path()` wrapper short-circuits to `None` while `crate::f
 **Gotcha**: `LocationInfo` enrichment with `VolumeManager` data happens in two places
 **Why**: `commands/volumes.rs::enrich_smb_connection_state` (for `list_volumes` IPC calls) and `volume_broadcast.rs::enrich_smb_connection_state` (for `volumes-changed` push events). Both must stay in sync. The pattern is: build the base `LocationInfo` from OS APIs, then cross-reference `VolumeManager` to add runtime state (`smb_connection_state`). If new enrichment fields are added, update both call sites.
 
+**Gotcha**: `append_mtp_volumes` is duplicated across `commands/volumes.rs` and `volume_broadcast.rs` (and their Linux counterparts), and both populate the MTP-only `usb_speed` field from `ConnectedDeviceInfo::device::usb_speed`
+**Why**: Same two-site sync problem as SMB enrichment, but for MTP-derived volume fields. Originally only `volume_broadcast.rs` set `usb_speed` from the device info; the `list_volumes` IPC variant hardcoded `None`, so the bootstrap call (used until the `volumes-changed` event lands) produced volumes with a missing dot until a later push refreshed them. Any new MTP-derived `LocationInfo` field needs to be set in BOTH `append_mtp_volumes` copies. The Linux variant lives in `commands/volumes_linux.rs` and mirrors the macOS one.
+
 ## Key decisions
 
 **Decision**: Gate launch-time icon fetches on the FDA decision (`crate::fda_gate::is_fda_pending_runtime()`)
diff --git a/apps/desktop/src-tauri/src/volumes/mod.rs b/apps/desktop/src-tauri/src/volumes/mod.rs
@@ -50,6 +50,10 @@ pub struct LocationInfo {
     pub is_read_only: bool,
     /// SMB connection state indicator. Only set for volumes with an active `SmbVolume`.
     pub smb_connection_state: Option<SmbConnectionState>,
+    /// Negotiated USB link speed. Set only for MTP/mobile volumes; everything
+    /// else carries `None`. Frontend maps to a label like "USB 3.2 Gen 1" and a
+    /// theoretical max MB/s for the volume switcher.
+    pub usb_speed: Option<crate::usb_speed::UsbSpeed>,
 }
 
 /// Default volume ID for the root filesystem.
@@ -257,6 +261,7 @@ pub fn resolve_path_volume_fast(path: &str) -> Option<VolumeInfo> {
             supports_trash,
             is_read_only: false,
             smb_connection_state: None,
+            usb_speed: None,
         })
     })
 }
@@ -372,6 +377,7 @@ fn get_favorites() -> Vec<LocationInfo> {
                 supports_trash,
                 is_read_only: false,
                 smb_connection_state: None,
+                usb_speed: None,
             }
         })
         .collect()
@@ -413,6 +419,7 @@ fn get_main_volume() -> Option<LocationInfo> {
                     supports_trash,
                     is_read_only: false,
                     smb_connection_state: None,
+                    usb_speed: None,
                 });
             }
         }
@@ -490,6 +497,7 @@ pub fn get_attached_volumes() -> Vec<LocationInfo> {
                 supports_trash,
                 is_read_only: false,
                 smb_connection_state: None,
+                usb_speed: None,
             });
         }
 
@@ -528,6 +536,7 @@ pub fn get_cloud_drives() -> Vec<LocationInfo> {
             supports_trash,
             is_read_only: false,
             smb_connection_state: None,
+            usb_speed: None,
         });
     }
 
@@ -556,6 +565,7 @@ pub fn get_cloud_drives() -> Vec<LocationInfo> {
                         supports_trash,
                         is_read_only: false,
                         smb_connection_state: None,
+                        usb_speed: None,
                     });
                 }
             }
diff --git a/apps/desktop/src-tauri/src/volumes_linux/mod.rs b/apps/desktop/src-tauri/src/volumes_linux/mod.rs
@@ -107,6 +107,9 @@ pub struct LocationInfo {
     pub is_read_only: bool,
     /// SMB connection state indicator. Always `None` on Linux (no smb2 session tracking yet).
     pub smb_connection_state: Option<String>,
+    /// Negotiated USB link speed. Set only for MTP/mobile volumes; everything
+    /// else carries `None`. Frontend maps to a label like "USB 3.2 Gen 1".
+    pub usb_speed: Option<crate::usb_speed::UsbSpeed>,
 }
 
 /// Information about volume space.
@@ -262,6 +265,7 @@ fn get_favorites(mounts: &[MountEntry]) -> Vec<LocationInfo> {
                 supports_trash,
                 is_read_only: false,
                 smb_connection_state: None,
+                usb_speed: None,
             }
         })
         .collect()
@@ -282,6 +286,7 @@ fn get_main_volume(mounts: &[MountEntry]) -> Option<LocationInfo> {
         supports_trash,
         is_read_only: false,
         smb_connection_state: None,
+        usb_speed: None,
     })
 }
 
@@ -329,6 +334,7 @@ pub fn get_mounted_volumes(mounts: &[MountEntry]) -> Vec<LocationInfo> {
             supports_trash,
             is_read_only: false,
             smb_connection_state: None,
+            usb_speed: None,
         });
     }
 
@@ -364,6 +370,7 @@ fn get_cloud_drives(mounts: &[MountEntry]) -> Vec<LocationInfo> {
                 supports_trash,
                 is_read_only: false,
                 smb_connection_state: None,
+                usb_speed: None,
             });
         }
     }
@@ -431,6 +438,7 @@ fn get_network_mounts() -> Vec<LocationInfo> {
                 supports_trash: false,
                 is_read_only: false,
                 smb_connection_state: None,
+                usb_speed: None,
             });
         }
     }
@@ -500,6 +508,7 @@ pub fn resolve_path_volume_fast(path: &str) -> Option<VolumeInfo> {
         supports_trash,
         is_read_only: false,
         smb_connection_state: None,
+        usb_speed: None,
     })
 }
 
diff --git a/apps/desktop/src/lib/file-explorer/navigation/CLAUDE.md b/apps/desktop/src/lib/file-explorer/navigation/CLAUDE.md
@@ -154,6 +154,16 @@ which tries stored credentials first; if none found or they fail, the backend re
 `onSmbUpgradeLogin` callback triggers `FilePane` to show `NetworkLoginForm` inline (same pattern as `ShareBrowser`).
 Submenu supports full keyboard navigation (ArrowRight to open, ArrowLeft/Escape to close, Enter to activate).
 
+### USB link-speed indicator (MTP)
+
+MTP volumes carry `usbSpeed: UsbSpeed` (`'low' | 'full' | 'high' | 'super' | 'super_plus'`) sourced from `mtp-rs` via
+the shared `crate::usb_speed::UsbSpeed`. `describeUsbSpeed(speed)` in `$lib/file-explorer/types` maps each tier to
+`{ tier, label, maxMBps }`; the breadcrumb renders a 5-tier rainbow dot (red → orange → yellow → light green → dark
+green; dark green is `--color-allow`, same shade as SMB direct) on the right of both the closed chip and each dropdown
+row. Tooltip shows `<label> (Max. <N> MB/s)\nNegotiated for this cable, port, and device` (the global tooltip CSS uses
+`white-space: pre-line`, so `\n` becomes a real line break). The dot is the only visual — no inline text in the chip and
+no extra line under the disk-space bar, by design.
+
 ### Dropdown and submenu UI patterns
 
 These patterns emerged during the volume picker implementation and should be followed in future dropdown/submenu work:
diff --git a/apps/desktop/src/lib/file-explorer/navigation/VolumeBreadcrumb.svelte b/apps/desktop/src/lib/file-explorer/navigation/VolumeBreadcrumb.svelte
diff --git a/apps/desktop/src/lib/file-explorer/types.ts b/apps/desktop/src/lib/file-explorer/types.ts
diff --git a/apps/desktop/src/lib/ipc/bindings.ts b/apps/desktop/src/lib/ipc/bindings.ts
diff --git a/scripts/check-css-unused/allowlist.go b/scripts/check-css-unused/allowlist.go

Original file line number	Diff line number	Diff line change
`@@ -41,6 +41,7 @@ pub fn list_mtp_devices() -> Vec<MtpDeviceInfo> {`
`41`	`41`	`manufacturer: d.manufacturer,`
`42`	`42`	`product: d.product,`
`43`	`43`	`serial_number: d.serial_number,`
	`44`	`+ usb_speed: d.speed.map(Into::into),`
`44`	`45`	`}`
`45`	`46`	`})`
`46`	`47`	`.collect()`