Hi, On 09-01-17 02:52, Yu, Qiang wrote:
Hi Hans, I forgot there is another difference, PRIME solution has to copy screen once before display to iGPU while MS_ALL_IN_ONE don't have to and can display what full screen app draws directly by page flip (for DRI2) which may be important for embedded platforms with week GPU and limited memory bandwidths.
Hmm, I guess you're talking imx6 + etnaviv now right, because with a discrete GPU + iGPU displaying the rendered frame, we are always going to need one copy from discrete-GPU RAM to system RAM. But I agree that getting rid of the extra copy for imx6 would be really good, I even dare to call it a must-have feature.
Benefit from common interface of drm/gbm/egl, may be modesetting can play a bigger role of span multi drm devices to give more optimization like this and: 1. multi render node, a single protocol screen to accept request and dispatch to each render node for render 2. multi display node associate with the render node (some display node has the same drm device with render node), so no need to handle bo tile-linear copy and each render node can handle request of its related display node.
Ack I agree that we would need to do better here, but I don't believe this should be some special mode activated by some special means, e.g. in the imx6 + etnaviv case the modesetting driver should simply recognize that they are sharing RAM and use page-flipping (passing buffer ownership between the 2) rather then copying, without the user needing to do anything special. Regards, Hans _______________________________________________ [email protected]: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: https://lists.x.org/mailman/listinfo/xorg-devel
