Hi Adrian,
On 23/07/2015 00:24, Adrian Alonso wrote:
DCIMVAC is upgraded to DCCIMVAC for the individual processor (Cortex-A7) that the DCIMVAC is executed on.
We should follow the linux dma follow. Before DMA read, first invalidate dcache then after DMA read, invalidate dcache again.
With the DMA direction DMA_FROM_DEVICE, the dcache need be invalidated again after the DMA completion. The reason is that we need explicity make sure the dcache been invalidated thus to get the DMA'ed memory correctly from the physical memory. Any cache-line fill during the DMA operations such as the pre-fetching can cause the DMA coherency issue, thus CPU get the stale data.
Pen has already sent this patch:
https://patchwork.ozlabs.org/patch/488273/
Please do not copy and resend patches that are already enqueded. Instead, advise that your patches depend on some previous ones. Thanks.
Best regards, Stefano Babic