From bc4e459e288920a20a86af620cb0302ad2010aee Mon Sep 17 00:00:00 2001
From: bunnie <bunnie@kosagi.com>
Date: Thu, 27 Nov 2025 12:34:40 +0800
Subject: [PATCH] convert spim txrx timeout from a hard-error into an error
 message

occassionally when the bus is loaded, some SPIM transactions won't
complete. this needs to be looked into a little more, i think...
---
 libs/bao1x-hal/src/sh1107.rs    | 12 ++++++++++--
 libs/bao1x-hal/src/udma/mod.rs  |  2 +-
 libs/bao1x-hal/src/udma/spim.rs |  3 ++-
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/libs/bao1x-hal/src/sh1107.rs b/libs/bao1x-hal/src/sh1107.rs
index 72e162f8e..8ced7bad2 100644
--- a/libs/bao1x-hal/src/sh1107.rs
+++ b/libs/bao1x-hal/src/sh1107.rs
@@ -423,7 +423,11 @@ impl<'a> Oled128x128<'a> {
                 .txrx_data_async_from_parts::<u8>(total_buf_len, len, true, false)
                 .expect("Couldn't initiate oled command");
         }
-        self.spim.txrx_await(false).unwrap();
+        self.spim.txrx_await(false).unwrap_or_else(|_e| {
+            #[cfg(feature = "std")]
+            log::error!("txrx err {:?}", _e);
+            &[]
+        });
     }
 
     pub fn init(&mut self) {
@@ -479,7 +483,11 @@ impl<'a> FrameBuffer for Oled128x128<'a> {
                     .txrx_data_async_from_parts::<u8>(page * chunk_size, chunk_size, true, false)
                     .expect("Couldn't initiate oled data transfer");
             }
-            self.spim.txrx_await(false).unwrap();
+            self.spim.txrx_await(false).unwrap_or_else(|_e| {
+                #[cfg(feature = "std")]
+                log::error!("txrx err {:?}", _e);
+                &[]
+            });
         }
     }
 
diff --git a/libs/bao1x-hal/src/udma/mod.rs b/libs/bao1x-hal/src/udma/mod.rs
index d9b9e4abc..bf2064959 100644
--- a/libs/bao1x-hal/src/udma/mod.rs
+++ b/libs/bao1x-hal/src/udma/mod.rs
@@ -270,7 +270,7 @@ pub trait Udma {
         ); */
         bank_addr.add(DmaReg::Saddr.into()).write_volatile(buf_addr);
         bank_addr.add(DmaReg::Size.into()).write_volatile((buf.len() * size_of::<T>()) as u32);
-        bank_addr.add(DmaReg::Cfg.into()).write_volatile(config | CFG_EN)
+        bank_addr.add(DmaReg::Cfg.into()).write_volatile(config | CFG_EN | CFG_BACKPRESSURE)
     }
     fn udma_reset(&self, bank: Bank) {
         unsafe {
diff --git a/libs/bao1x-hal/src/udma/spim.rs b/libs/bao1x-hal/src/udma/spim.rs
index ff83f52fd..93266e639 100644
--- a/libs/bao1x-hal/src/udma/spim.rs
+++ b/libs/bao1x-hal/src/udma/spim.rs
@@ -657,7 +657,7 @@ impl Spim {
             if let Some(pending) = self.pending_txrx.take() {
                 let tt = xous_api_ticktimer::Ticktimer::new().unwrap();
                 let start = tt.elapsed_ms();
-                let mut now = tt.elapsed_ms();
+                let mut now = start;
                 const TIMEOUT_MS: u64 = 500;
                 while (self.udma_busy(Bank::Tx) || self.udma_busy(Bank::Rx) || self.udma_busy(Bank::Custom))
                     && ((now - start) < TIMEOUT_MS)
@@ -690,6 +690,7 @@ impl Spim {
                         self.csr().base().add(Bank::Rx as usize).add(DmaReg::Saddr.into()).write_volatile(0);
                         self.csr().base().add(Bank::Rx as usize).add(DmaReg::Cfg.into()).write_volatile(0); // clear bit is not self-clearing
                     };
+                    return Err(xous::Error::Timeout);
                 }
                 Ok(&self.rx_buf()[..pending])
             } else {