Le lundi 04 mars 2024 à 15:07 +0100, Christian König a écrit :
Am 04.03.24 um 14:59 schrieb Paul Cercueil:
[SNIP]
- dma_to_ram = buffer->direction ==
IIO_BUFFER_DIRECTION_IN;
- if (dma_to_ram) {
/** If we're writing to the DMABUF, make surewe don't have
* readers*/retl = dma_resv_wait_timeout(dmabuf->resv,DMA_RESV_USAGE_READ, true,
timeout);if (retl == 0)retl = -EBUSY;if (retl < 0) {ret = (int)retl;goto err_resv_unlock;}- }
- if (buffer->access->lock_queue)
buffer->access->lock_queue(buffer);- ret = dma_resv_reserve_fences(dmabuf->resv, 1);
- if (ret)
goto err_queue_unlock;- dma_resv_add_fence(dmabuf->resv, &fence->base,
dma_resv_usage_rw(dma_to_ram));That is incorrect use of the function dma_resv_usage_rw(). That function is for retrieving fences and not adding them.
See the function implementation and comments, when you use it like this you get exactly what you don't want.
No, I get exactly what I want. If "dma_to_ram", I get DMA_RESV_USAGE_READ, otherwise I get DMA_RESV_USAGE_WRITE.
Ah, so basically !dma_to_ram means that you have a write access to the buffer?
"dma_to_ram" means the data flows from the DMA to the RAM.
... Which means that it writes the buffer, so you are right, this is wrong.
If you really don't like the macro, I can inline things here.
Yeah, that would still be incorrect use. The dma__resv_usage_rw() is for retrieving the fences to sync to for read and write operations and should never be used together with dma_fence_resv_add().
Ok, I'll inline it (and fix it) then.
Cheers, -Paul