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| author |  Cliff L. Biffle <cliff@oxide.computer>
| 2020-05-24 17:19:57 -0700 |
|---|---|---|
| committer | Cliff L. Biffle <cliff@oxide.computer>
| 2020-05-24 17:19:57 -0700 |
| commit | 97141b951b044bd4a06478454a179d633f28d148 (patch) | |
| tree | 6283febb39959b153502e95f5dbba327875c52b9 | |
| parent | fc19f3e1588e7486716667dbd0db37c6dc41d0ed (diff) | |
| download | cortex-m-97141b951b044bd4a06478454a179d633f28d148.tar.gz cortex-m-97141b951b044bd4a06478454a179d633f28d148.tar.zst cortex-m-97141b951b044bd4a06478454a179d633f28d148.zip | |
ITM: don't test reserved bits in is_fifo_ready
On ARMv7-M, bits 31:1 of the value read from STIMx are reserved, so
comparing them against zero is a bad idea.
On ARMv8-M, bit 1 has been repurposed to indicate DISABLED. This means
that the is_fifo_ready impl hangs forever when ITM is disabled on a
Cortex-M33 (for example).
Changed to test only the FIFOREADY bit.
| -rw-r--r-- | src/peripheral/itm.rs | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/peripheral/itm.rs b/src/peripheral/itm.rs index 0b63524..57d2ff8 100644 --- a/src/peripheral/itm.rs +++ b/src/peripheral/itm.rs @@ -55,6 +55,6 @@ impl Stim { /// Returns `true` if the stimulus port is ready to accept more data #[inline] pub fn is_fifo_ready(&self) -> bool { - unsafe { ptr::read_volatile(self.register.get()) == 1 } + unsafe { ptr::read_volatile(self.register.get()) & 1 == 1 } } } |