Re: DMA-buf and uncached system memory

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi

Am 23.06.22 um 10:26 schrieb Christian König:
Am 23.06.22 um 10:13 schrieb Thomas Zimmermann:
Hi Christian

Am 15.02.21 um 09:58 schrieb Christian König:
Hi guys,

we are currently working an Freesync and direct scan out from system memory on AMD APUs in A+A laptops.

On problem we stumbled over is that our display hardware needs to scan out from uncached system memory and we currently don't have a way to communicate that through DMA-buf.

For our specific use case at hand we are going to implement something driver specific, but the question is should we have something more generic for this?

I had a patchset here that extends iosys-map (former dma-buf-map) with caching information. I'll post a copy.

Oh, nice. But why on iosys-map? We need that per DMA-buf.

It's returned via the dma-buf's vmap call within the iosys-map structure. If the dma-buf moves, the following vmap calls always return updated caching information. Maybe it's not quite what you need for Freesync?

I'll use this for format-conversion helpers, which do some optimizations for uncached memory.

Anyway, I have to look for that patch...

Best regards
Thomas


Thanks,
Christian.


Sorry for being late to reply.

Best regards
Thomas


After all the system memory access pattern is a PCIe extension and as such something generic.

Regards,
Christian.
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel



--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

Attachment: OpenPGP_signature
Description: OpenPGP digital signature


[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux