[GitHub] [incubator-nuttx] davids5 opened a new pull request #5062: stm32f7:sdmmc invalidate before DMA to avoid eviction overwrite

[GitBox <gi...@apache.org>]

davids5 opened a new pull request #5062:
URL: https://github.com/apache/incubator-nuttx/pull/5062


   ## Summary
   
     For FAT the same buffer is used for read and writes, there
     is a possibility a cache line is dirty. But the fs is
     not dirty and will not write the sector to disk. This can
     be seen  https://github.com/PX4/NuttX/pull/175
   
     When the system is busy that cache line can be evicted after the
     RX DMA has completed and overwrite the data in memory. The solution
     is to invalidate before the DMA to prevent an evection causing an
     overwite, and after the DMA it to insure coherency.
   
   ## Impact
   
   random FS errors that are disk state dependent. 
   
   ## Testing
   
   px4 16 tasks  of `tests dataman`
   
   


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[GitHub] [incubator-nuttx] xiaoxiang781216 merged pull request #5062: stm32f7:sdmmc invalidate before DMA to avoid eviction overwrite

[GitBox <gi...@apache.org>]

xiaoxiang781216 merged pull request #5062:
URL: https://github.com/apache/incubator-nuttx/pull/5062


   


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