On Monday, October 12, 2015 at 02:55:03 PM, Thomas Chou wrote:
Hi Marek,
Hi Thomas,
On 10/12/2015 06:32 PM, Marek Vasut wrote:
Wouldn't invalidate_dcache_range() be enough here ? You don't care about the data in the newly allocated area at this point I guess -- either you fill them in and then flush, for DMA from CPU to device OR you receive data from device to CPU and then you invalidate this buffer again.
No. We cannot use invalidate cache here. This is related to cache design of nios2, kind of direct mapped cache.
Can you please expand on this ?
btw. I was thinking about this whole cache situation. Please don't get me wrong, my intention is not to put way more work unto you and/or grind you about minor details. I hope it doesn't look that way to you.
Best regards, Marek Vasut