Re: [PATCH v2 2/3] rust: dma: convert the read/write macros to return Result

Benno Lossin
2025-04-10T15:11:14Z

On Thu Apr 10, 2025 at 1:54 PM CEST, Danilo Krummrich wrote:
> On Thu, Apr 10, 2025 at 11:58:17AM +0300, Abdiel Janulgue wrote:
>> @@ -78,13 +74,14 @@ impl Drop for DmaSampleDriver {
>> fn drop(&mut self) {
>> dev_info!(self.pdev.as_ref(), "Unload DMA test driver.\n");
>>
>> - let _ = || -> Result {
>> - for (i, value) in TEST_VALUES.into_iter().enumerate() {
>> - assert_eq!(kernel::dma_read!(self.ca[i].h), value.0);
>> - assert_eq!(kernel::dma_read!(self.ca[i].b), value.1);
>> - }
>> - Ok(())
>> - }();
>> + for (i, value) in TEST_VALUES.into_iter().enumerate() {
>> + let val0 = kernel::dma_read!(self.ca[i].h);
>> + let val1 = kernel::dma_read!(self.ca[i].b);
>> + assert!(val0.is_ok());
>> + assert!(val1.is_ok());
>> + assert_eq!(val0.unwrap(), value.0);
>> + assert_eq!(val1.unwrap(), value.1);
>
> Maybe use if-let to avoid the unwrap?
>
> if let Ok(val0) = val0 {
> assert_eq!(val0, value.0);
> }
>
> I know it's a bit pointless, since we know it must be ok, but the educational
> message of the example should be to check and not to unwrap, so maybe that's
> better.

The if-let will silently ignore any errors, so I don't think that it's
fit for example code either.

---
Cheers,
Benno