Hi, [add Daniel Vetter] [cc dri-devel] Den 29.05.2019 15.09, skrev Pierre Yves MORDRET: > Hello Noralf, > > Sorry for bothering you with question but I need to better understand the > rational about a patch you did in DRM/GEM. > > First of all, let me introduce myself. > I'm currently employee to STMicroelectronics company and in charge of GPU > integration within STM32 MPU (Cortex A7 + Cortex M4) > > On Cortex A7 is running a Linux Kernel 4.19 as for today. > > We came across some trouble when we switch from Kernel 4.14 to 4.19 for GPU > stack. On august you submit this commit : > > 90378e58919285637aa0f063c04ba0c6449d98b1 > drm/gem: drm_gem_dumb_map_offset(): reject dma-buf > > Reject mapping an imported dma-buf since is's an invalid use-case. > > In Userland GPU stack we have such statements : > bo_map_fd > DRM_IOCTL_MODE_MAP_DUMB > mmap (offset) > > With the patch above, ioctl returns an error EINVAL and prevents the nmap. > As for today we revert this patch and it works fine in our end. > > Thus the questions are : > - what is the rational behind this fix ? > - What we doing wrong this situation ? > - What do we need in such situation ? > I need to pass those on to Daniel Vetter (DRM maintainer) since he wanted the change. The details were never clear to me. Some of the discussion is here: https://patchwork.freedesktop.org/patch/172242/ Noralf. > Many thanks in advance. > Best Regards > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
