Re: [PATCH] virtio_ring: switch to dma_XX barriers for rpmsg

From: Paolo Bonzini
Date: Thu Apr 19 2018 - 13:48:34 EST


On 19/04/2018 19:46, Michael S. Tsirkin wrote:
>> This should be okay, but I wonder if there should be a virtio_wmb(...)
>> or an "if (weak_barriers) wmb()" before the "writel" in vm_notify
>> (drivers/virtio/virtio_mmio.c).
>>
>> Thanks,
>>
>> Paolo
> That one uses weak barriers AFAIK.
>
> IIUC you mean rproc_virtio_notify.
>
> I suspect it works because specific kick callbacks have a barrier internally.

Yes, that one. At least keystone_rproc_kick doesn't seem to have a barrier.

Paolo