>-----Original Message----- >From: Michel Dänzer <michel@xxxxxxxxxxx> >Sent: Friday, December 21, 2018 5:28 PM >To: Deng, Emily <Emily.Deng@xxxxxxx> >Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx >Subject: Re: [PATCH] drm/amdgpu/virtual_dce: Need to pin the fb's bo > >On 2018-12-21 10:17 a.m., Deng, Emily wrote: >>> From: amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of >>> Deng, Emily >>>> From: Michel Dänzer <michel@xxxxxxxxxxx> On 2018-12-21 9:45 a.m., >>>> Deng, Emily wrote: >>>>>> From: Michel Dänzer <michel@xxxxxxxxxxx> On 2018-12-21 8:26 a.m., >>>>>> Emily Deng wrote: >>>>>>> When the bo is used to set mode, the bo need to be pinned. >>>>>> >>>>>> On second thought, why does the BO need to be pinned? When using >>>>>> the display hardware, the BO needs to be pinned to prevent it from >>>>>> being moved while the hardware is scanning out from it, but that >>>>>> shouldn't be >>>> necessary here. >>>>> The pin here is used for scan out the buffer by remote display app. >>>> >>>> I still don't understand why pinning is needed. What mechanism does >>>> the remote display app use to access the BO contents? >>> Sorry, I am not familiar with the remote display app. Maybe it will >>> use drm ioctl function to get the current crtc's fb's information, >>> and get the content in the fb's buffer object by mmap or translate >>> the bo to an OpenGL texture for next rendering. Maybe don't need to >>> pin the bo here, as the use has no different with other normal bos. >>> So please ignore the patch, and will send another patch to remove the unpin >the fb's bo code. >> It seems to be hard to remove all the pin for virtual_dce, as it uses some >common code in amdgpu_display.c. > >Because of amdgpu_display_unpin_work_func? That might be as simple as >replacing > > schedule_work(&works->unpin_work); > >with > > kfree(works->shared); > kfree(works); > >in dce_virtual_pageflip. But the amdgpu_display_crtc_page_flip_target will pin the new_bo, then we don't need to unpin it? Best wishes Emily Deng > > >-- >Earthling Michel Dänzer | http://www.amd.com >Libre software enthusiast | Mesa and X developer _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
