stm32/(q|o|x)spi: Change the default device size to maximum allowable.

embassy-stm32/CHANGELOG.md

@@ -31,6 +31,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - feat: stm32/usart: add `eager_reads` option to control if buffered readers return as soon as possible or after more data is available ([#4668](https://github.com/embassy-rs/embassy/pull/4668))
 - feat: stm32/usart: add `de_assertion_time` and `de_deassertion_time` config options
 - change: stm32/uart: BufferedUartRx now returns all available bytes from the internal buffer
+- change: stm32/(q|o|x)spi: Set the default memory size to the maximum allowable for qspi/ospi/xspi so that the indirect read command is able to read more than 2 bytes. This avoids a potential gotcha.
 
 ## 0.4.0 - 2025-08-26
 

embassy-stm32/src/ospi/mod.rs

@@ -69,7 +69,10 @@ impl Default for Config {
         Self {
             fifo_threshold: FIFOThresholdLevel::_16Bytes, // 32 bytes FIFO, half capacity
             memory_type: MemoryType::Micron,
-            device_size: MemorySize::Other(0),
+            // We set the default is the maximum size of the memory
+            // This value limits the possible read length using indirect read mode
+            // To prevent a gotcha we choose to use a high value
+            device_size: MemorySize::Other(31),
             chip_select_high_time: ChipSelectHighTime::_5Cycle,
             free_running_clock: false,
             clock_mode: false,

embassy-stm32/src/qspi/mod.rs

@@ -72,7 +72,10 @@ pub struct Config {
 impl Default for Config {
     fn default() -> Self {
         Self {
-            memory_size: MemorySize::Other(0),
+            // We set the default is the maximum size of the memory
+            // This value limits the possible read length using indirect read mode
+            // To prevent a gotcha we choose to use a high value
+            memory_size: MemorySize::Other(31),
             address_size: AddressSize::_24bit,
             prescaler: 128,
             fifo_threshold: FIFOThresholdLevel::_17Bytes,

embassy-stm32/src/xspi/mod.rs

@@ -65,7 +65,10 @@ impl Default for Config {
         Self {
             fifo_threshold: FIFOThresholdLevel::_16Bytes, // 32 bytes FIFO, half capacity
             memory_type: MemoryType::Micron,
-            device_size: MemorySize::Other(0),
+            // We set the default is the maximum size of the memory
+            // This value limits the possible read length using indirect read mode
+            // To prevent a gotcha we choose to use a high value
+            device_size: MemorySize::Other(31),
             chip_select_high_time: ChipSelectHighTime::_5Cycle,
             free_running_clock: false,
             clock_mode: false,