Re: [PATCH v2] dmaengine: edma: Align the memcpy acnt array size with the transfer
From: Vinod Koul
Date: Thu Sep 21 2017 - 13:17:44 EST
On Mon, Sep 18, 2017 at 11:16:26AM +0300, Peter Ujfalusi wrote:
> Memory to Memory transfers does not have any special alignment needs
> regarding to acnt array size, but if one of the areas are in memory mapped
> regions (like PCIe memory), we need to make sure that the acnt array size
> is aligned with the mem copy parameters.
> Before "dmaengine: edma: Optimize memcpy operation" change the memcpy was set
> up in a different way: acnt == number of bytes in a word based on
> __ffs((src | dest | len), bcnt and ccnt for looping the necessary number of
> words to comlete the trasnfer.
> Instead of reverting the commit we can fix it to make sure that the ACNT size
> is aligned to the traswnfer.