On 17/06/2024 16:50, Michel Dänzer wrote:
On 2024-06-17 12:29, Pierre Ossman wrote:
Just to avoid any uncertainty, are both of these things done implicitly by
gbm_bo_map()/gbm_bo_unmap()?
I did test adding those steps just in case, but unfortunately did not see an
improvement. My order was:
1. gbm_bo_import(GBM_BO_USE_RENDERING)
2. gbm_bo_get_fd()
3. Wait for client to request displaying the buffer
4. gbm_bo_map(GBM_BO_TRANSFER_READ)
5. select(fd+1, &fds, NULL, NULL, NULL)
*If* select() is needed, it needs to be before gbm_bo_map(), because the latter
may perform a blit from the real BO to a staging one for CPU access.
Can I know whether it is needed or not? Or should I be cautious and
always do it?
I also assumed I should do select() with readfds set when I want to
read, and writefds set when I want to write?
Still, after moving it before the map the issue unfortunately remains. :/
A recording of the issue is available here, in case the behaviour rings
a bell for anyone:
http://www.cendio.com/~ossman/dri3/Screencast%20from%202024-06-17%2017-06-50.webm
(tried to include it as an attachment, but that email was filtered out
somewhere)
Regards,
--
Pierre Ossman Software Development
Cendio AB https://cendio.com
Teknikringen 8 https://twitter.com/ThinLinc
583 30 Linköping https://facebook.com/ThinLinc
Phone: +46-13-214600
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
