[PATCH] drm/shmem-helpers: Simplify dma-buf importing

[Boris Brezillon]

On Fri, 29 May 2020 15:34:28 +0200
Boris Brezillon <boris.brezillon at collabora.com> wrote:

> Hi Daniel,
> 
> On Wed, 20 May 2020 20:02:32 +0200
> Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> 
> > - Ditch the ->pages array
> > - Make it a private gem bo, which means no shmem object, which means
> >   fireworks if anyone calls drm_gem_object_get_pages. But we've just
> >   made sure that's all covered.
> > 
> > v2: Rebase
> > 
> > Acked-by: Thomas Zimmermann <tzimmermann at suse.de>
> > Cc: Gerd Hoffmann <kraxel at redhat.com>
> > Cc: Rob Herring <robh at kernel.org>
> > Cc: Noralf Trønnes <noralf at tronnes.org>
> > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>  
> 
> I see a bunch of
> 
> [   38.261313] ------------[ cut here ]------------
> [   38.261740] WARNING: CPU: 4 PID: 2945 at drivers/gpu/drm/drm_gem_shmem_helper.c:137 drm_gem_shmem_free_object+0xb4/0xe0
> [   38.262676] Modules linked in:
> [   38.262949] CPU: 4 PID: 2945 Comm: Xwayland Not tainted 5.7.0-rc1-00111-g9c7e526c43d0 #520
> [   38.263667] Hardware name: Radxa ROCK Pi 4 (DT)
> [   38.264062] pstate: 60000005 (nZCv daif -PAN -UAO)
> [   38.264482] pc : drm_gem_shmem_free_object+0xb4/0xe0
> [   38.264916] lr : drm_gem_shmem_free_object+0x38/0xe0
> [   38.265348] sp : ffff800011cebbb0
> [   38.265639] x29: ffff800011cebbb0 x28: ffff800011cebd88 
> [   38.266102] x27: 0000000000000000 x26: ffff000072a1f400 
> [   38.266566] x25: 0000000000000009 x24: ffff000072a1f400 
> [   38.267029] x23: 0000000000000002 x22: ffff000079409080 
> [   38.267492] x21: ffff000079409280 x20: ffff00006c304800 
> [   38.267955] x19: ffff00006c304800 x18: 0000000000000000 
> [   38.268417] x17: 0000000000000000 x16: 0000000000000000 
> [   38.268880] x15: 0000000000000000 x14: 0000000000000000 
> [   38.269343] x13: 0001000000000000 x12: 0000000000000008 
> [   38.269806] x11: 000000000000ffff x10: 0000000000000000 
> [   38.270269] x9 : 0000000000000001 x8 : 0000000000210d00 
> [   38.270732] x7 : 0000000000000001 x6 : ffff800011307980 
> [   38.271195] x5 : ffff00006641c240 x4 : ffff00006ee1b400 
> [   38.271656] x3 : 0000000000000004 x2 : aafbc6f338cf6000 
> [   38.272119] x1 : 0000000000000000 x0 : 00000000ffffffff 
> [   38.272583] Call trace:
> [   38.272799]  drm_gem_shmem_free_object+0xb4/0xe0
> [   38.273203]  panfrost_gem_free_object+0xf0/0x128
> [   38.273608]  drm_gem_object_free+0x18/0x40
> [   38.273967]  drm_gem_object_handle_put_unlocked+0xe4/0xe8
> [   38.274439]  drm_gem_object_release_handle+0x6c/0x98
> [   38.274872]  drm_gem_handle_delete+0x84/0x140
> [   38.275253]  drm_gem_close_ioctl+0x2c/0x40
> [   38.275612]  drm_ioctl_kernel+0xb8/0x108
> [   38.275954]  drm_ioctl+0x214/0x450
> [   38.276255]  ksys_ioctl+0xa0/0xe0
> [   38.276546]  __arm64_sys_ioctl+0x1c/0x28
> [   38.276891]  el0_svc_common.constprop.0+0x68/0x160
> [   38.277310]  do_el0_svc+0x20/0x80
> [   38.277602]  el0_sync_handler+0x10c/0x178
> [   38.277952]  el0_sync+0x140/0x180
> [   38.278242] ---[ end trace db5754ef8b213ce5 ]---
> 
> after applying that patch. Didn't have time to dig through it, unfortunately.

Sorry, I forgot to mention that I'm testing on panfrost.