• Tomoya MORINAGA's avatar
    spi-topcliff-pch: Fix overrun issue · f3e03e2e
    Tomoya MORINAGA authored
    We found that adding load, Rx data sometimes drops.(with DMA transfer mode)
    The cause is that before starting Rx-DMA processing, Tx-DMA processing starts.
    This causes FIFO overrun occurs.
    
    This patch fixes the issue by modifying FIFO tx-threshold and DMA descriptor
    size like below.
    
                          Current                   this patch
    Rx-descriptor   4Byte+12Byte*341    -->    12Byte*340-4Byte-12Byte
    Rx-threshold                   (Not modified)
    Tx-descriptor   4Byte+12Byte*341    -->    16Byte-12Byte*340
    Rx-threshold    12Byte              -->    2Byte
    Signed-off-by: default avatarTomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
    Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
    f3e03e2e
spi-topcliff-pch.c 46.5 KB