diff mbox series

drm/vc4: Set `fbdev_probe` in `struct vc5_drm_driver`

Message ID 20241009004332.1901833-1-mcanal@igalia.com (mailing list archive)
State New, archived
Headers show
Series drm/vc4: Set `fbdev_probe` in `struct vc5_drm_driver` | expand

Commit Message

Maíra Canal Oct. 9, 2024, 12:40 a.m. UTC 
Currently, when booting the RPi 4B, we get a NULL pointer dereference:

[    7.642883] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038
[    7.642926] Mem abort info:
[    7.642938]   ESR = 0x0000000096000044
[    7.642951]   EC = 0x25: DABT (current EL), IL = 32 bits
[    7.642968]   SET = 0, FnV = 0
[    7.642981]   EA = 0, S1PTW = 0
[    7.642993]   FSC = 0x04: level 0 translation fault
[    7.643007] Data abort info:
[    7.643017]   ISV = 0, ISS = 0x00000044, ISS2 = 0x00000000
[    7.643032]   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
[    7.643046]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[    7.643063] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107487000
[    7.643081] [0000000000000038] pgd=0000000000000000, p4d=0000000000000000
[    7.643113] Internal error: Oops: 0000000096000044 [#1] PREEMPT SMP
[    7.643131] Modules linked in: snd_bcm2835(C)  [...] vc4 v3d [...]
drm_shmem_helper drm_dma_helper drm_kms_helper drm [...] ipv6
[    7.643377] CPU: 1 UID: 0 PID: 48 Comm: kworker/u16:2 Tainted: G         C         6.12.0-rc1-00310-g2c34a5464007 #185
[    7.643407] Tainted: [C]=CRAP
[    7.643419] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
[    7.643438] Workqueue: events_unbound deferred_probe_work_func
[    7.643477] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    7.643499] pc : __drm_fb_helper_initial_config_and_unlock+0x40c/0x588 [drm_kms_helper]
[    7.643616] lr : __drm_fb_helper_initial_config_and_unlock+0x374/0x588 [drm_kms_helper]
[    7.643710] sp : ffff8000806c3900
[    7.643724] x29: ffff8000806c3950 x28: ffff431b01a3ec14 x27: 0000000000000010
[    7.643758] x26: ffff431b0369f000 x25: 0000000036314752 x24: ffff431b003b6200
[    7.643790] x23: ffff431b0369f000 x22: 00000000000002d0 x21: ffff431b003b6030
[    7.643821] x20: ffff431b003b6030 x19: ffff431b003b6000 x18: ffff431b002e6e48
[    7.643852] x17: 0000000000000001 x16: ffffb19c2f10614c x15: 0000000000000000
[    7.643882] x14: 0000000000000000 x13: ffff431b003b62f0 x12: 0000000000000500
[    7.643913] x11: 0000000000000000 x10: 0000000000000000 x9 : 005d6e6f6362665b
[    7.643945] x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
[    7.643975] x5 : ffffb19bcb45c59c x4 : 0000000000001e00 x3 : ffffb19bcb420c20
[    7.644005] x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffff431b003b6000
[    7.644036] Call trace:
[    7.644049]  __drm_fb_helper_initial_config_and_unlock+0x40c/0x588 [drm_kms_helper]
[    7.644149]  drm_fb_helper_initial_config+0x34/0x4c [drm_kms_helper]
[    7.644240]  drm_fbdev_client_hotplug+0x74/0xc8 [drm_kms_helper]
[    7.644331]  drm_client_register+0x58/0xa0 [drm]
[    7.644571]  drm_fbdev_client_setup+0xc4/0x17c [drm_kms_helper]
[    7.644664]  drm_client_setup_with_fourcc+0x28/0x60 [drm_kms_helper]
[    7.644755]  vc4_drm_bind+0x218/0x264 [vc4]
[    7.644855]  try_to_bring_up_aggregate_device+0x168/0x1b4
[    7.644884]  __component_add+0xb8/0x158
[    7.644905]  component_add+0x14/0x20
[    7.644925]  vc4_hvs_dev_probe+0x1c/0x28 [vc4]
[    7.645019]  platform_probe+0xa8/0xd0
[    7.645045]  really_probe+0x128/0x2c8
[    7.645065]  __driver_probe_device+0xa0/0x128
[    7.645086]  driver_probe_device+0x3c/0x1f8
[    7.645106]  __device_attach_driver+0x118/0x140
[    7.645127]  bus_for_each_drv+0xf4/0x14c
[    7.645145]  __device_attach+0xfc/0x194
[    7.645164]  device_initial_probe+0x14/0x20
[    7.645184]  bus_probe_device+0x94/0x100
[    7.645202]  deferred_probe_work_func+0x88/0xc4
[    7.645223]  process_scheduled_works+0x194/0x2c4
[    7.645246]  worker_thread+0x290/0x39c
[    7.645265]  kthread+0xfc/0x184
[    7.645289]  ret_from_fork+0x10/0x20
[    7.645317] Code: f2ac6c49 aa1303e0 f2cdcde9 f2e00ba9 (f9001d09)
[    7.645338] ---[ end trace 0000000000000000 ]---

This happens because commit 45903624e9fc ("drm/vc4: Run DRM default client
setup") only added DRM_FBDEV_DMA_DRIVER_OPS to `struct vc4_drm_driver`
and didn't add it to `struct vc5_drm_driver`. The `struct vc4_drm_driver`
is used in RPi 0-3, as VC4 is also a render node in those RPis. But RPi 4
and 5 use V3D as the render node and VC4 as modeset node and therefore,
use `struct vc5_drm_driver`.

This commit adds DRM_FBDEV_DMA_DRIVER_OPS to `struct vc5_drm_driver`,
ensuring that `fbdev_probe` exists for all VC4 generations.

Fixes: 45903624e9fc ("drm/vc4: Run DRM default client setup")
Signed-off-by: Maíra Canal <mcanal@igalia.com>
---
 drivers/gpu/drm/vc4/vc4_drv.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Thomas Zimmermann Oct. 9, 2024, 6:59 a.m. UTC | #1 
Hi

Am 09.10.24 um 02:40 schrieb Maíra Canal:
> Currently, when booting the RPi 4B, we get a NULL pointer dereference:
>
> [    7.642883] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038
> [    7.642926] Mem abort info:
> [    7.642938]   ESR = 0x0000000096000044
> [    7.642951]   EC = 0x25: DABT (current EL), IL = 32 bits
> [    7.642968]   SET = 0, FnV = 0
> [    7.642981]   EA = 0, S1PTW = 0
> [    7.642993]   FSC = 0x04: level 0 translation fault
> [    7.643007] Data abort info:
> [    7.643017]   ISV = 0, ISS = 0x00000044, ISS2 = 0x00000000
> [    7.643032]   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
> [    7.643046]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> [    7.643063] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107487000
> [    7.643081] [0000000000000038] pgd=0000000000000000, p4d=0000000000000000
> [    7.643113] Internal error: Oops: 0000000096000044 [#1] PREEMPT SMP
> [    7.643131] Modules linked in: snd_bcm2835(C)  [...] vc4 v3d [...]
> drm_shmem_helper drm_dma_helper drm_kms_helper drm [...] ipv6
> [    7.643377] CPU: 1 UID: 0 PID: 48 Comm: kworker/u16:2 Tainted: G         C         6.12.0-rc1-00310-g2c34a5464007 #185
> [    7.643407] Tainted: [C]=CRAP
> [    7.643419] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
> [    7.643438] Workqueue: events_unbound deferred_probe_work_func
> [    7.643477] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [    7.643499] pc : __drm_fb_helper_initial_config_and_unlock+0x40c/0x588 [drm_kms_helper]
> [    7.643616] lr : __drm_fb_helper_initial_config_and_unlock+0x374/0x588 [drm_kms_helper]
> [    7.643710] sp : ffff8000806c3900
> [    7.643724] x29: ffff8000806c3950 x28: ffff431b01a3ec14 x27: 0000000000000010
> [    7.643758] x26: ffff431b0369f000 x25: 0000000036314752 x24: ffff431b003b6200
> [    7.643790] x23: ffff431b0369f000 x22: 00000000000002d0 x21: ffff431b003b6030
> [    7.643821] x20: ffff431b003b6030 x19: ffff431b003b6000 x18: ffff431b002e6e48
> [    7.643852] x17: 0000000000000001 x16: ffffb19c2f10614c x15: 0000000000000000
> [    7.643882] x14: 0000000000000000 x13: ffff431b003b62f0 x12: 0000000000000500
> [    7.643913] x11: 0000000000000000 x10: 0000000000000000 x9 : 005d6e6f6362665b
> [    7.643945] x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
> [    7.643975] x5 : ffffb19bcb45c59c x4 : 0000000000001e00 x3 : ffffb19bcb420c20
> [    7.644005] x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffff431b003b6000
> [    7.644036] Call trace:
> [    7.644049]  __drm_fb_helper_initial_config_and_unlock+0x40c/0x588 [drm_kms_helper]
> [    7.644149]  drm_fb_helper_initial_config+0x34/0x4c [drm_kms_helper]
> [    7.644240]  drm_fbdev_client_hotplug+0x74/0xc8 [drm_kms_helper]
> [    7.644331]  drm_client_register+0x58/0xa0 [drm]
> [    7.644571]  drm_fbdev_client_setup+0xc4/0x17c [drm_kms_helper]
> [    7.644664]  drm_client_setup_with_fourcc+0x28/0x60 [drm_kms_helper]
> [    7.644755]  vc4_drm_bind+0x218/0x264 [vc4]
> [    7.644855]  try_to_bring_up_aggregate_device+0x168/0x1b4
> [    7.644884]  __component_add+0xb8/0x158
> [    7.644905]  component_add+0x14/0x20
> [    7.644925]  vc4_hvs_dev_probe+0x1c/0x28 [vc4]
> [    7.645019]  platform_probe+0xa8/0xd0
> [    7.645045]  really_probe+0x128/0x2c8
> [    7.645065]  __driver_probe_device+0xa0/0x128
> [    7.645086]  driver_probe_device+0x3c/0x1f8
> [    7.645106]  __device_attach_driver+0x118/0x140
> [    7.645127]  bus_for_each_drv+0xf4/0x14c
> [    7.645145]  __device_attach+0xfc/0x194
> [    7.645164]  device_initial_probe+0x14/0x20
> [    7.645184]  bus_probe_device+0x94/0x100
> [    7.645202]  deferred_probe_work_func+0x88/0xc4
> [    7.645223]  process_scheduled_works+0x194/0x2c4
> [    7.645246]  worker_thread+0x290/0x39c
> [    7.645265]  kthread+0xfc/0x184
> [    7.645289]  ret_from_fork+0x10/0x20
> [    7.645317] Code: f2ac6c49 aa1303e0 f2cdcde9 f2e00ba9 (f9001d09)
> [    7.645338] ---[ end trace 0000000000000000 ]---
>
> This happens because commit 45903624e9fc ("drm/vc4: Run DRM default client
> setup") only added DRM_FBDEV_DMA_DRIVER_OPS to `struct vc4_drm_driver`
> and didn't add it to `struct vc5_drm_driver`. The `struct vc4_drm_driver`
> is used in RPi 0-3, as VC4 is also a render node in those RPis. But RPi 4
> and 5 use V3D as the render node and VC4 as modeset node and therefore,
> use `struct vc5_drm_driver`.
>
> This commit adds DRM_FBDEV_DMA_DRIVER_OPS to `struct vc5_drm_driver`,
> ensuring that `fbdev_probe` exists for all VC4 generations.
>
> Fixes: 45903624e9fc ("drm/vc4: Run DRM default client setup")
> Signed-off-by: Maíra Canal <mcanal@igalia.com>

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>

Sorry for forgetting about this.

Best regards
Thomas

> ---
>   drivers/gpu/drm/vc4/vc4_drv.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
> index 13a1ecddbca3..a238f76a6073 100644
> --- a/drivers/gpu/drm/vc4/vc4_drv.c
> +++ b/drivers/gpu/drm/vc4/vc4_drv.c
> @@ -238,6 +238,7 @@ const struct drm_driver vc5_drm_driver = {
>   #endif
>   
>   	DRM_GEM_DMA_DRIVER_OPS_WITH_DUMB_CREATE(vc5_dumb_create),
> +	DRM_FBDEV_DMA_DRIVER_OPS,
>   
>   	.fops = &vc4_drm_fops,
>
Maxime Ripard Oct. 9, 2024, 7:55 a.m. UTC | #2 
On Wed, Oct 09, 2024 at 08:59:29AM GMT, Thomas Zimmermann wrote:
> Hi
> 
> Am 09.10.24 um 02:40 schrieb Maíra Canal:
> > Currently, when booting the RPi 4B, we get a NULL pointer dereference:
> > 
> > [    7.642883] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038
> > [    7.642926] Mem abort info:
> > [    7.642938]   ESR = 0x0000000096000044
> > [    7.642951]   EC = 0x25: DABT (current EL), IL = 32 bits
> > [    7.642968]   SET = 0, FnV = 0
> > [    7.642981]   EA = 0, S1PTW = 0
> > [    7.642993]   FSC = 0x04: level 0 translation fault
> > [    7.643007] Data abort info:
> > [    7.643017]   ISV = 0, ISS = 0x00000044, ISS2 = 0x00000000
> > [    7.643032]   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
> > [    7.643046]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> > [    7.643063] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107487000
> > [    7.643081] [0000000000000038] pgd=0000000000000000, p4d=0000000000000000
> > [    7.643113] Internal error: Oops: 0000000096000044 [#1] PREEMPT SMP
> > [    7.643131] Modules linked in: snd_bcm2835(C)  [...] vc4 v3d [...]
> > drm_shmem_helper drm_dma_helper drm_kms_helper drm [...] ipv6
> > [    7.643377] CPU: 1 UID: 0 PID: 48 Comm: kworker/u16:2 Tainted: G         C         6.12.0-rc1-00310-g2c34a5464007 #185
> > [    7.643407] Tainted: [C]=CRAP
> > [    7.643419] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
> > [    7.643438] Workqueue: events_unbound deferred_probe_work_func
> > [    7.643477] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> > [    7.643499] pc : __drm_fb_helper_initial_config_and_unlock+0x40c/0x588 [drm_kms_helper]
> > [    7.643616] lr : __drm_fb_helper_initial_config_and_unlock+0x374/0x588 [drm_kms_helper]
> > [    7.643710] sp : ffff8000806c3900
> > [    7.643724] x29: ffff8000806c3950 x28: ffff431b01a3ec14 x27: 0000000000000010
> > [    7.643758] x26: ffff431b0369f000 x25: 0000000036314752 x24: ffff431b003b6200
> > [    7.643790] x23: ffff431b0369f000 x22: 00000000000002d0 x21: ffff431b003b6030
> > [    7.643821] x20: ffff431b003b6030 x19: ffff431b003b6000 x18: ffff431b002e6e48
> > [    7.643852] x17: 0000000000000001 x16: ffffb19c2f10614c x15: 0000000000000000
> > [    7.643882] x14: 0000000000000000 x13: ffff431b003b62f0 x12: 0000000000000500
> > [    7.643913] x11: 0000000000000000 x10: 0000000000000000 x9 : 005d6e6f6362665b
> > [    7.643945] x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
> > [    7.643975] x5 : ffffb19bcb45c59c x4 : 0000000000001e00 x3 : ffffb19bcb420c20
> > [    7.644005] x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffff431b003b6000
> > [    7.644036] Call trace:
> > [    7.644049]  __drm_fb_helper_initial_config_and_unlock+0x40c/0x588 [drm_kms_helper]
> > [    7.644149]  drm_fb_helper_initial_config+0x34/0x4c [drm_kms_helper]
> > [    7.644240]  drm_fbdev_client_hotplug+0x74/0xc8 [drm_kms_helper]
> > [    7.644331]  drm_client_register+0x58/0xa0 [drm]
> > [    7.644571]  drm_fbdev_client_setup+0xc4/0x17c [drm_kms_helper]
> > [    7.644664]  drm_client_setup_with_fourcc+0x28/0x60 [drm_kms_helper]
> > [    7.644755]  vc4_drm_bind+0x218/0x264 [vc4]
> > [    7.644855]  try_to_bring_up_aggregate_device+0x168/0x1b4
> > [    7.644884]  __component_add+0xb8/0x158
> > [    7.644905]  component_add+0x14/0x20
> > [    7.644925]  vc4_hvs_dev_probe+0x1c/0x28 [vc4]
> > [    7.645019]  platform_probe+0xa8/0xd0
> > [    7.645045]  really_probe+0x128/0x2c8
> > [    7.645065]  __driver_probe_device+0xa0/0x128
> > [    7.645086]  driver_probe_device+0x3c/0x1f8
> > [    7.645106]  __device_attach_driver+0x118/0x140
> > [    7.645127]  bus_for_each_drv+0xf4/0x14c
> > [    7.645145]  __device_attach+0xfc/0x194
> > [    7.645164]  device_initial_probe+0x14/0x20
> > [    7.645184]  bus_probe_device+0x94/0x100
> > [    7.645202]  deferred_probe_work_func+0x88/0xc4
> > [    7.645223]  process_scheduled_works+0x194/0x2c4
> > [    7.645246]  worker_thread+0x290/0x39c
> > [    7.645265]  kthread+0xfc/0x184
> > [    7.645289]  ret_from_fork+0x10/0x20
> > [    7.645317] Code: f2ac6c49 aa1303e0 f2cdcde9 f2e00ba9 (f9001d09)
> > [    7.645338] ---[ end trace 0000000000000000 ]---
> > 
> > This happens because commit 45903624e9fc ("drm/vc4: Run DRM default client
> > setup") only added DRM_FBDEV_DMA_DRIVER_OPS to `struct vc4_drm_driver`
> > and didn't add it to `struct vc5_drm_driver`. The `struct vc4_drm_driver`
> > is used in RPi 0-3, as VC4 is also a render node in those RPis. But RPi 4
> > and 5 use V3D as the render node and VC4 as modeset node and therefore,
> > use `struct vc5_drm_driver`.
> > 
> > This commit adds DRM_FBDEV_DMA_DRIVER_OPS to `struct vc5_drm_driver`,
> > ensuring that `fbdev_probe` exists for all VC4 generations.
> > 
> > Fixes: 45903624e9fc ("drm/vc4: Run DRM default client setup")
> > Signed-off-by: Maíra Canal <mcanal@igalia.com>
> 
> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>

It's the third time it was sent:

https://lore.kernel.org/dri-devel/20241002-vc4_fbdev_fix-v1-1-8737bd11b147@raspberrypi.com/
https://lore.kernel.org/dri-devel/20241003092826.1942901-3-m.szyprowski@samsung.com/

Maxime
Dave Stevenson Oct. 9, 2024, 10:45 a.m. UTC | #3 
On Wed, 9 Oct 2024 at 08:55, Maxime Ripard <mripard@kernel.org> wrote:
>
> On Wed, Oct 09, 2024 at 08:59:29AM GMT, Thomas Zimmermann wrote:
> > Hi
> >
> > Am 09.10.24 um 02:40 schrieb Maíra Canal:
> > > Currently, when booting the RPi 4B, we get a NULL pointer dereference:
> > >
> > > [    7.642883] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038
> > > [    7.642926] Mem abort info:
> > > [    7.642938]   ESR = 0x0000000096000044
> > > [    7.642951]   EC = 0x25: DABT (current EL), IL = 32 bits
> > > [    7.642968]   SET = 0, FnV = 0
> > > [    7.642981]   EA = 0, S1PTW = 0
> > > [    7.642993]   FSC = 0x04: level 0 translation fault
> > > [    7.643007] Data abort info:
> > > [    7.643017]   ISV = 0, ISS = 0x00000044, ISS2 = 0x00000000
> > > [    7.643032]   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
> > > [    7.643046]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
> > > [    7.643063] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107487000
> > > [    7.643081] [0000000000000038] pgd=0000000000000000, p4d=0000000000000000
> > > [    7.643113] Internal error: Oops: 0000000096000044 [#1] PREEMPT SMP
> > > [    7.643131] Modules linked in: snd_bcm2835(C)  [...] vc4 v3d [...]
> > > drm_shmem_helper drm_dma_helper drm_kms_helper drm [...] ipv6
> > > [    7.643377] CPU: 1 UID: 0 PID: 48 Comm: kworker/u16:2 Tainted: G         C         6.12.0-rc1-00310-g2c34a5464007 #185
> > > [    7.643407] Tainted: [C]=CRAP
> > > [    7.643419] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
> > > [    7.643438] Workqueue: events_unbound deferred_probe_work_func
> > > [    7.643477] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> > > [    7.643499] pc : __drm_fb_helper_initial_config_and_unlock+0x40c/0x588 [drm_kms_helper]
> > > [    7.643616] lr : __drm_fb_helper_initial_config_and_unlock+0x374/0x588 [drm_kms_helper]
> > > [    7.643710] sp : ffff8000806c3900
> > > [    7.643724] x29: ffff8000806c3950 x28: ffff431b01a3ec14 x27: 0000000000000010
> > > [    7.643758] x26: ffff431b0369f000 x25: 0000000036314752 x24: ffff431b003b6200
> > > [    7.643790] x23: ffff431b0369f000 x22: 00000000000002d0 x21: ffff431b003b6030
> > > [    7.643821] x20: ffff431b003b6030 x19: ffff431b003b6000 x18: ffff431b002e6e48
> > > [    7.643852] x17: 0000000000000001 x16: ffffb19c2f10614c x15: 0000000000000000
> > > [    7.643882] x14: 0000000000000000 x13: ffff431b003b62f0 x12: 0000000000000500
> > > [    7.643913] x11: 0000000000000000 x10: 0000000000000000 x9 : 005d6e6f6362665b
> > > [    7.643945] x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
> > > [    7.643975] x5 : ffffb19bcb45c59c x4 : 0000000000001e00 x3 : ffffb19bcb420c20
> > > [    7.644005] x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffff431b003b6000
> > > [    7.644036] Call trace:
> > > [    7.644049]  __drm_fb_helper_initial_config_and_unlock+0x40c/0x588 [drm_kms_helper]
> > > [    7.644149]  drm_fb_helper_initial_config+0x34/0x4c [drm_kms_helper]
> > > [    7.644240]  drm_fbdev_client_hotplug+0x74/0xc8 [drm_kms_helper]
> > > [    7.644331]  drm_client_register+0x58/0xa0 [drm]
> > > [    7.644571]  drm_fbdev_client_setup+0xc4/0x17c [drm_kms_helper]
> > > [    7.644664]  drm_client_setup_with_fourcc+0x28/0x60 [drm_kms_helper]
> > > [    7.644755]  vc4_drm_bind+0x218/0x264 [vc4]
> > > [    7.644855]  try_to_bring_up_aggregate_device+0x168/0x1b4
> > > [    7.644884]  __component_add+0xb8/0x158
> > > [    7.644905]  component_add+0x14/0x20
> > > [    7.644925]  vc4_hvs_dev_probe+0x1c/0x28 [vc4]
> > > [    7.645019]  platform_probe+0xa8/0xd0
> > > [    7.645045]  really_probe+0x128/0x2c8
> > > [    7.645065]  __driver_probe_device+0xa0/0x128
> > > [    7.645086]  driver_probe_device+0x3c/0x1f8
> > > [    7.645106]  __device_attach_driver+0x118/0x140
> > > [    7.645127]  bus_for_each_drv+0xf4/0x14c
> > > [    7.645145]  __device_attach+0xfc/0x194
> > > [    7.645164]  device_initial_probe+0x14/0x20
> > > [    7.645184]  bus_probe_device+0x94/0x100
> > > [    7.645202]  deferred_probe_work_func+0x88/0xc4
> > > [    7.645223]  process_scheduled_works+0x194/0x2c4
> > > [    7.645246]  worker_thread+0x290/0x39c
> > > [    7.645265]  kthread+0xfc/0x184
> > > [    7.645289]  ret_from_fork+0x10/0x20
> > > [    7.645317] Code: f2ac6c49 aa1303e0 f2cdcde9 f2e00ba9 (f9001d09)
> > > [    7.645338] ---[ end trace 0000000000000000 ]---
> > >
> > > This happens because commit 45903624e9fc ("drm/vc4: Run DRM default client
> > > setup") only added DRM_FBDEV_DMA_DRIVER_OPS to `struct vc4_drm_driver`
> > > and didn't add it to `struct vc5_drm_driver`. The `struct vc4_drm_driver`
> > > is used in RPi 0-3, as VC4 is also a render node in those RPis. But RPi 4
> > > and 5 use V3D as the render node and VC4 as modeset node and therefore,
> > > use `struct vc5_drm_driver`.
> > >
> > > This commit adds DRM_FBDEV_DMA_DRIVER_OPS to `struct vc5_drm_driver`,
> > > ensuring that `fbdev_probe` exists for all VC4 generations.
> > >
> > > Fixes: 45903624e9fc ("drm/vc4: Run DRM default client setup")
> > > Signed-off-by: Maíra Canal <mcanal@igalia.com>
> >
> > Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
>
> It's the third time it was sent:
>
> https://lore.kernel.org/dri-devel/20241002-vc4_fbdev_fix-v1-1-8737bd11b147@raspberrypi.com/
> https://lore.kernel.org/dri-devel/20241003092826.1942901-3-m.szyprowski@samsung.com/

It is. No one responded to my version. I can merge Marek's vc4 change
with my R-b, or now Maira's with Thomas and mine.
But both the other two submissions also included a patch so that
drm_fb_helper handled the error more cleanly [1 and 2]. I'm still new
to maintainership, but I don't believe I'm in a position to merge
either of those.

  Dave

[1] https://lore.kernel.org/dri-devel/20241002-vc4_fbdev_fix-v1-2-8737bd11b147@raspberrypi.com/
[2] https://lore.kernel.org/dri-devel/20241003092826.1942901-2-m.szyprowski@samsung.com/
Maíra Canal Oct. 9, 2024, 10:56 a.m. UTC | #4 
Hi Dave,

On 10/9/24 07:45, Dave Stevenson wrote:
> On Wed, 9 Oct 2024 at 08:55, Maxime Ripard <mripard@kernel.org> wrote:
>>
>> On Wed, Oct 09, 2024 at 08:59:29AM GMT, Thomas Zimmermann wrote:
>>> Hi
>>>
>>> Am 09.10.24 um 02:40 schrieb Maíra Canal:
>>>> Currently, when booting the RPi 4B, we get a NULL pointer dereference:
>>>>
>>>> [    7.642883] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038
>>>> [    7.642926] Mem abort info:
>>>> [    7.642938]   ESR = 0x0000000096000044
>>>> [    7.642951]   EC = 0x25: DABT (current EL), IL = 32 bits
>>>> [    7.642968]   SET = 0, FnV = 0
>>>> [    7.642981]   EA = 0, S1PTW = 0
>>>> [    7.642993]   FSC = 0x04: level 0 translation fault
>>>> [    7.643007] Data abort info:
>>>> [    7.643017]   ISV = 0, ISS = 0x00000044, ISS2 = 0x00000000
>>>> [    7.643032]   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
>>>> [    7.643046]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
>>>> [    7.643063] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107487000
>>>> [    7.643081] [0000000000000038] pgd=0000000000000000, p4d=0000000000000000
>>>> [    7.643113] Internal error: Oops: 0000000096000044 [#1] PREEMPT SMP
>>>> [    7.643131] Modules linked in: snd_bcm2835(C)  [...] vc4 v3d [...]
>>>> drm_shmem_helper drm_dma_helper drm_kms_helper drm [...] ipv6
>>>> [    7.643377] CPU: 1 UID: 0 PID: 48 Comm: kworker/u16:2 Tainted: G         C         6.12.0-rc1-00310-g2c34a5464007 #185
>>>> [    7.643407] Tainted: [C]=CRAP
>>>> [    7.643419] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
>>>> [    7.643438] Workqueue: events_unbound deferred_probe_work_func
>>>> [    7.643477] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>>> [    7.643499] pc : __drm_fb_helper_initial_config_and_unlock+0x40c/0x588 [drm_kms_helper]
>>>> [    7.643616] lr : __drm_fb_helper_initial_config_and_unlock+0x374/0x588 [drm_kms_helper]
>>>> [    7.643710] sp : ffff8000806c3900
>>>> [    7.643724] x29: ffff8000806c3950 x28: ffff431b01a3ec14 x27: 0000000000000010
>>>> [    7.643758] x26: ffff431b0369f000 x25: 0000000036314752 x24: ffff431b003b6200
>>>> [    7.643790] x23: ffff431b0369f000 x22: 00000000000002d0 x21: ffff431b003b6030
>>>> [    7.643821] x20: ffff431b003b6030 x19: ffff431b003b6000 x18: ffff431b002e6e48
>>>> [    7.643852] x17: 0000000000000001 x16: ffffb19c2f10614c x15: 0000000000000000
>>>> [    7.643882] x14: 0000000000000000 x13: ffff431b003b62f0 x12: 0000000000000500
>>>> [    7.643913] x11: 0000000000000000 x10: 0000000000000000 x9 : 005d6e6f6362665b
>>>> [    7.643945] x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
>>>> [    7.643975] x5 : ffffb19bcb45c59c x4 : 0000000000001e00 x3 : ffffb19bcb420c20
>>>> [    7.644005] x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffff431b003b6000
>>>> [    7.644036] Call trace:
>>>> [    7.644049]  __drm_fb_helper_initial_config_and_unlock+0x40c/0x588 [drm_kms_helper]
>>>> [    7.644149]  drm_fb_helper_initial_config+0x34/0x4c [drm_kms_helper]
>>>> [    7.644240]  drm_fbdev_client_hotplug+0x74/0xc8 [drm_kms_helper]
>>>> [    7.644331]  drm_client_register+0x58/0xa0 [drm]
>>>> [    7.644571]  drm_fbdev_client_setup+0xc4/0x17c [drm_kms_helper]
>>>> [    7.644664]  drm_client_setup_with_fourcc+0x28/0x60 [drm_kms_helper]
>>>> [    7.644755]  vc4_drm_bind+0x218/0x264 [vc4]
>>>> [    7.644855]  try_to_bring_up_aggregate_device+0x168/0x1b4
>>>> [    7.644884]  __component_add+0xb8/0x158
>>>> [    7.644905]  component_add+0x14/0x20
>>>> [    7.644925]  vc4_hvs_dev_probe+0x1c/0x28 [vc4]
>>>> [    7.645019]  platform_probe+0xa8/0xd0
>>>> [    7.645045]  really_probe+0x128/0x2c8
>>>> [    7.645065]  __driver_probe_device+0xa0/0x128
>>>> [    7.645086]  driver_probe_device+0x3c/0x1f8
>>>> [    7.645106]  __device_attach_driver+0x118/0x140
>>>> [    7.645127]  bus_for_each_drv+0xf4/0x14c
>>>> [    7.645145]  __device_attach+0xfc/0x194
>>>> [    7.645164]  device_initial_probe+0x14/0x20
>>>> [    7.645184]  bus_probe_device+0x94/0x100
>>>> [    7.645202]  deferred_probe_work_func+0x88/0xc4
>>>> [    7.645223]  process_scheduled_works+0x194/0x2c4
>>>> [    7.645246]  worker_thread+0x290/0x39c
>>>> [    7.645265]  kthread+0xfc/0x184
>>>> [    7.645289]  ret_from_fork+0x10/0x20
>>>> [    7.645317] Code: f2ac6c49 aa1303e0 f2cdcde9 f2e00ba9 (f9001d09)
>>>> [    7.645338] ---[ end trace 0000000000000000 ]---
>>>>
>>>> This happens because commit 45903624e9fc ("drm/vc4: Run DRM default client
>>>> setup") only added DRM_FBDEV_DMA_DRIVER_OPS to `struct vc4_drm_driver`
>>>> and didn't add it to `struct vc5_drm_driver`. The `struct vc4_drm_driver`
>>>> is used in RPi 0-3, as VC4 is also a render node in those RPis. But RPi 4
>>>> and 5 use V3D as the render node and VC4 as modeset node and therefore,
>>>> use `struct vc5_drm_driver`.
>>>>
>>>> This commit adds DRM_FBDEV_DMA_DRIVER_OPS to `struct vc5_drm_driver`,
>>>> ensuring that `fbdev_probe` exists for all VC4 generations.
>>>>
>>>> Fixes: 45903624e9fc ("drm/vc4: Run DRM default client setup")
>>>> Signed-off-by: Maíra Canal <mcanal@igalia.com>
>>>
>>> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
>>
>> It's the third time it was sent:
>>
>> https://lore.kernel.org/dri-devel/20241002-vc4_fbdev_fix-v1-1-8737bd11b147@raspberrypi.com/
>> https://lore.kernel.org/dri-devel/20241003092826.1942901-3-m.szyprowski@samsung.com/
> 
> It is. No one responded to my version. I can merge Marek's vc4 change
> with my R-b, or now Maira's with Thomas and mine.
> But both the other two submissions also included a patch so that
> drm_fb_helper handled the error more cleanly [1 and 2]. I'm still new
> to maintainership, but I don't believe I'm in a position to merge
> either of those.
> 

I'm sorry, those patches went unnoticed by me. For me, the priority
would be to fix RPi 4 display as soon as possible. As you were the
first one to send the fix, you can apply the fix to drm-misc-next
with my R-b. I won't R-b the second patch, as I believe Thomas has more
experience with fbdev.

Best Regards,
- Maíra

>    Dave
> 
> [1] https://lore.kernel.org/dri-devel/20241002-vc4_fbdev_fix-v1-2-8737bd11b147@raspberrypi.com/
> [2] https://lore.kernel.org/dri-devel/20241003092826.1942901-2-m.szyprowski@samsung.com/
diff mbox series

Patch

diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
index 13a1ecddbca3..a238f76a6073 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.c
+++ b/drivers/gpu/drm/vc4/vc4_drv.c
@@ -238,6 +238,7 @@  const struct drm_driver vc5_drm_driver = {
 #endif
 
 	DRM_GEM_DMA_DRIVER_OPS_WITH_DUMB_CREATE(vc5_dumb_create),
+	DRM_FBDEV_DMA_DRIVER_OPS,
 
 	.fops = &vc4_drm_fops,