On 10/5/22 17:47, Parav Pandit wrote: > @@ -1927,10 +1927,12 @@ There are some more advanced barrier functions: > before we read the data from the descriptor, and the dma_wmb() allows > us to guarantee the data is written to the descriptor before the device > can see it now has ownership. The dma_mb() implies both a dma_rmb() and > - a dma_wmb(). Note that, when using writel(), a prior wmb() is not needed > - to guarantee that the cache coherent memory writes have completed before > - writing to the MMIO region. The cheaper writel_relaxed() does not provide > - this guarantee and must not be used here. > + a dma_wmb(). Note that, when using writel(), a prior barrier is not > + needed to guarantee that the cache coherent memory writes have completed > + before writing to the MMIO region. The cheaper writel_relaxed() does not > + provide this guarantee and must not be used here. Hence, writeX() is always > + preferred which inserts needed platform specific barrier before writing to > + the specified MMIO region. > Did you mean that writeX() is write() function family? -- An old man doll... just what I always wanted! - Clara
