[PATCH v5 10/15] gpu: nova-core: return ENOMSG for an unmatched GSP message

[John Hubbard <jhubbard@nvidia.com>]

The GSP posts unsolicited events on the same queue as command replies,
so a receive that asks for one message type has to report that the
message at the queue head was a different one.

That case returned ERANGE, which means a value outside a valid range and
says nothing about a message.

Return ENOMSG, no message of the desired type, instead.

Suggested-by: Gary Guo <gary@garyguo.net>
Suggested-by: Alexandre Courbot <acourbot@nvidia.com>
Assisted-by: LLM
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 drivers/gpu/nova-core/gsp/cmdq.rs      | 6 +++---
 drivers/gpu/nova-core/gsp/commands.rs  | 2 +-
 drivers/gpu/nova-core/gsp/sequencer.rs | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/nova-core/gsp/cmdq.rs b/drivers/gpu/nova-core/gsp/cmdq.rs
index 4591f6c61ce6..ad2a14d08cb0 100644
--- a/drivers/gpu/nova-core/gsp/cmdq.rs
+++ b/drivers/gpu/nova-core/gsp/cmdq.rs
@@ -585,7 +585,7 @@ pub(crate) fn send_command<M>(&self, command: M) -> Result<M::Reply>
         loop {
             match inner.receive_msg::<M::Reply>(Self::RECEIVE_TIMEOUT) {
                 Ok(reply) => break Ok(reply),
-                Err(ERANGE) => continue,
+                Err(ENOMSG) => continue,
                 Err(e) => break Err(e),
             }
         }
@@ -828,7 +828,7 @@ fn wait_for_msg(&self, timeout: Delta) -> Result<GspMessage<'_>> {
     /// - `ETIMEDOUT` if `timeout` has elapsed before any message becomes available.
     /// - `EIO` if there was some inconsistency (e.g. message shorter than advertised) on the
     ///   message queue.
-    /// - `ERANGE` if the message was not the awaited reply.
+    /// - `ENOMSG` if the message was not the awaited reply.
     ///
     /// Error codes returned by [`MessageFromGsp::read`] are propagated as-is.
     fn receive_msg<M: MessageFromGsp>(&mut self, timeout: Delta) -> Result<M>
@@ -859,7 +859,7 @@ fn receive_msg<M: MessageFromGsp>(&mut self, timeout: Delta) -> Result<M>
         } else {
             self.log_event(function, seq);
 
-            Err(ERANGE)
+            Err(ENOMSG)
         };
 
         // Advance the read pointer past this message.
diff --git a/drivers/gpu/nova-core/gsp/commands.rs b/drivers/gpu/nova-core/gsp/commands.rs
index 59d7d7fb15e8..0c787fd689bf 100644
--- a/drivers/gpu/nova-core/gsp/commands.rs
+++ b/drivers/gpu/nova-core/gsp/commands.rs
@@ -191,7 +191,7 @@ pub(crate) fn wait_gsp_init_done(cmdq: &Cmdq<'_>) -> Result {
     loop {
         match cmdq.receive_msg::<GspInitDone>(Cmdq::RECEIVE_TIMEOUT) {
             Ok(_) => break Ok(()),
-            Err(ERANGE) => continue,
+            Err(ENOMSG) => continue,
             Err(e) => break Err(e),
         }
     }
diff --git a/drivers/gpu/nova-core/gsp/sequencer.rs b/drivers/gpu/nova-core/gsp/sequencer.rs
index dae34c11eb05..1782ed7d7ca6 100644
--- a/drivers/gpu/nova-core/gsp/sequencer.rs
+++ b/drivers/gpu/nova-core/gsp/sequencer.rs
@@ -346,7 +346,7 @@ pub(crate) fn run(
         let seq_info = loop {
             match cmdq.receive_msg::<GspSequence>(Cmdq::RECEIVE_TIMEOUT) {
                 Ok(seq_info) => break seq_info,
-                Err(ERANGE) => continue,
+                Err(ENOMSG) => continue,
                 Err(e) => return Err(e),
             }
         };
-- 
2.55.0