Hi Christian,
Could I simply force it by overwriting peer2peer after the attach call?
Cheers Dirk
Hi Dirk,
Any ideas?
Could be anything. Most likely cause is that some function things the two device can't communicate directly with each other.
Please provide a full dmesg and "lspci -t -nn -v" as attachment and note which devices should communicate with which.
I'm currently on vacation so it could take a while till I have time to look deeper into this.
Christian.
Am 01.10.2018 um 15:07 schrieb Dirk Eibach:
Hi Christian,
I took the repository Dieter suggested and gave it a spin. I am not sure, if I got the API right.
In userspace I create a bo and get a fd. bo = gbm_bo_create(gbm, w, h, GBM_FORMAT_ARGB8888, GBM_BO_USE_LINEAR); dmabuf_fd = gbm_bo_get_fd(bo);
Then I pass the fd to the grabber driver. There I get a sgt, that I want to pass to the DMA-machine. struct dma_buf_attach_info dma_buf_attach_info = { .dev = &engine->xdev->pdev->dev, .peer2peer = true, }; dma_buf = dma_buf_get(xdma_dma_buf_ioctl.dma_buf_fd); dma_buf_attach_info.dmabuf = dma_buf; dma_buf_attachment = dma_buf_attach(&dma_buf_attach_info); sgt = dma_buf_map_attachment(dma_buf_attachment, DMA_TO_DEVICE);
But the addresses in the sgt do not look like PCIe addresses at at all.
Any ideas?
Cheers Dirk Am Sa., 29. Sep. 2018 um 11:53 Uhr schrieb Dieter Nützel <
Dieter@nuetzel-hh.de>:
Hello Dirk,
I think Christian is talking about this branch:
https://cgit.freedesktop.org/~deathsimple/linux/log/?h=p2p
His 'home' is, here: https://cgit.freedesktop.org/~deathsimple/linux/
Happy hacking! ;-)
Dieter
Am 29.09.2018 10:17, schrieb Dirk Eibach:
This is work in progress.
I published patches to enable DMA_buf P2P a few months ago, but now I'm waiting for the PCI subsystem to pick up core support for this.
Great news! Can you give me a link to this series so I can already have a look?
I can prepare you a branch based on current upstream kernel next week if you want to test this.
That would be awesome, thanks.
Cheers Dirk _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel