Merge pull request #2971 from mattico/usb-ep-send

embassy-usb-synopsys-otg: impl Sync for EpState

.vscode/settings.json

@@ -9,12 +9,14 @@
   "rust-analyzer.check.noDefaultFeatures": true,
   "rust-analyzer.cargo.noDefaultFeatures": true,
   "rust-analyzer.showUnlinkedFileNotification": false,
-  // uncomment the target of your chip.
+  // Uncomment the target of your chip.
   //"rust-analyzer.cargo.target": "thumbv6m-none-eabi",
   //"rust-analyzer.cargo.target": "thumbv7m-none-eabi",
   "rust-analyzer.cargo.target": "thumbv7em-none-eabi",
+  //"rust-analyzer.cargo.target": "thumbv7em-none-eabihf",
   //"rust-analyzer.cargo.target": "thumbv8m.main-none-eabihf",
   "rust-analyzer.cargo.features": [
+    // Comment out these features when working on the examples. Most example crates do not have any cargo features.
     "stm32f446re",
     "time-driver-any",
     "unstable-pac",
@@ -22,9 +24,10 @@
     "rt",
   ],
   "rust-analyzer.linkedProjects": [
-    // Uncomment ONE line for the chip you want to work on.
-    // This makes rust-analyzer work on the example crate and all its dependencies.
     "embassy-stm32/Cargo.toml",
+    // To work on the examples, comment the line above and all of the cargo.features lines,
+    // then uncomment ONE line below to select the chip you want to work on.
+    // This makes rust-analyzer work on the example crate and all its dependencies.
     // "examples/nrf52840-rtic/Cargo.toml",
     // "examples/nrf5340/Cargo.toml",
     // "examples/nrf-rtos-trace/Cargo.toml",

embassy-usb-synopsys-otg/src/lib.rs

@@ -221,6 +221,12 @@ struct EpState {
     out_size: AtomicU16,
 }
 
+// SAFETY: The EndpointAllocator ensures that the buffer points to valid memory exclusive for each endpoint and is
+// large enough to hold the maximum packet size. Access to the buffer is synchronized between the USB interrupt and the
+// EndpointOut impl using the out_size atomic variable.
+unsafe impl Send for EpState {}
+unsafe impl Sync for EpState {}
+
 struct ControlPipeSetupState {
     /// Holds received SETUP packets. Available if [Ep0State::setup_ready] is true.
     setup_data: UnsafeCell<[u8; 8]>,
@@ -1034,7 +1040,7 @@ impl<'d> embassy_usb_driver::EndpointOut for Endpoint<'d, Out> {
                     return Poll::Ready(Err(EndpointError::BufferOverflow));
                 }
 
-                // SAFETY: exclusive access ensured by `ep_out_size` atomic variable
+                // SAFETY: exclusive access ensured by `out_size` atomic variable
                 let data = unsafe { core::slice::from_raw_parts(*self.state.out_buffer.get(), len as usize) };
                 buf[..len as usize].copy_from_slice(data);