[alsa-devel] A bug about cache inconsistency report

[Hans Hu(SH-RD)]

Hi All,

               Try send an email.

               Appearance:
when use non-snoop + ioctl path combination, an issue occurs:
usage: aplay -D plughw:0,0 44100_S16_LE_2c.wav
Ubuntu, it performance intermittently noise;

Root case:
               Function set_pages_array_wc marked the PTE of the original address; Function set_memory_wc marked the PTE both original and after vmaped address.
[cid:image002.png at 01D428FF.92621520]
However, cache or not in transmission process is based on the PTE of the later, and the set_pages_array_wc did't mark it, so a cache inconsistency issue occurs.

               Related bug:
               SHA1 ID: 9ddf1aeb2134e72275c97a2c6ff2e3eb04f2f27a

Best Regards!
Hans Hu



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