Commits on Oct 3, 2024

1. clear any pending interrupt flag …

   While debugging, I found that on RP2040 the first looped background
   write on a StateMachine would be garbled: It the first few outputs
   would be as expected, but then the data would go back to the start
   of the buffer.
   
   I realized that this could be due to there already being a pending
   interrupt on this DMA channel that had occurred previously but never
   been acknowledged. In fact, by printing the value of `dma_hw->intr`
   before this, I could see that it was the case.
   
   After this change, both my special case reproducer from the related
   issue works, and the odd gaps in LED data transmission seen in the
   WIP code for TM1814 LEDs was fixed.
   
   I never saw this problem on Feather RP2350, only on Metro RP2040,
   but I don't know why. It would depend on what had previously
   happened to the DMA channel that ends up allocated to this PIO
   state machine. Less likely, it could depend on details of the DMA
   peripheral that changed between the chips.
   
   Closes: adafruit#9678

   

   jepler committed Oct 3, 2024
   Configuration menu

   • View commit details
   • Copy full SHA for d0e8030
   • Browse repository at this point

   Copy the full SHA

   d0e8030 View commit details

   Browse the repository at this point in the history