have the core spinor routines automatically retry on failure

normally we never see these failures, but, as we are seeing
flash wear-out on the CI machine the writes can take
long enough that we get some concurrent requests. As a work-around,
just automatically retry a few times before throwing the error
back to the caller.

services/spinor/src/lib.rs

@@ -174,17 +174,25 @@ impl Spinor {
  // acquire a write lock on the unit
  #[cfg(not(test))]
  {
- let response = send_message(self.conn,
- Message::new_blocking_scalar(Opcode::AcquireExclusive.to_usize().unwrap(),
- self.token[0] as usize,
- self.token[1] as usize,
- self.token[2] as usize,
- self.token[3] as usize,
- )
- ).expect("couldn't send AcquireExclusive message to Spinor hardware!");
- if let xous::Result::Scalar1(result) = response {
- if result == 0 {
- return Err(SpinorError::BusyTryAgain)
+ const RETRY_LIMIT: usize = 5;
+ for i in 0..RETRY_LIMIT {
+ let response = send_message(self.conn,
+ Message::new_blocking_scalar(Opcode::AcquireExclusive.to_usize().unwrap(),
+ self.token[0] as usize,
+ self.token[1] as usize,
+ self.token[2] as usize,
+ self.token[3] as usize,
+ )
+ ).expect("couldn't send AcquireExclusive message to Spinor hardware!");
+ if let xous::Result::Scalar1(result) = response {
+ if result == 0 {
+ if i == RETRY_LIMIT - 1 {
+ return Err(SpinorError::BusyTryAgain)
+ }
+ xous::yield_slice();
+ } else {
+ break;
+ }
  }
  }
  }
@@ -235,17 +243,25 @@ impl Spinor {
  // acquire a write lock on the unit
  #[cfg(not(test))]
  {
- let response = send_message(self.conn,
- Message::new_blocking_scalar(Opcode::AcquireExclusive.to_usize().unwrap(),
- self.token[0] as usize,
- self.token[1] as usize,
- self.token[2] as usize,
- self.token[3] as usize,
- )
- ).expect("couldn't send AcquireExclusive message to Spinor hardware!");
- if let xous::Result::Scalar1(result) = response {
- if result == 0 {
- return Err(SpinorError::BusyTryAgain)
+ const RETRY_LIMIT: usize = 5;
+ for i in 0..RETRY_LIMIT {
+ let response = send_message(self.conn,
+ Message::new_blocking_scalar(Opcode::AcquireExclusive.to_usize().unwrap(),
+ self.token[0] as usize,
+ self.token[1] as usize,
+ self.token[2] as usize,
+ self.token[3] as usize,
+ )
+ ).expect("couldn't send AcquireExclusive message to Spinor hardware!");
+ if let xous::Result::Scalar1(result) = response {
+ if result == 0 {
+ if i == RETRY_LIMIT - 1 {
+ return Err(SpinorError::BusyTryAgain)
+ }
+ xous::yield_slice();
+ } else {
+ break;
+ }
  }
  }
  }