[PATCH] drm/rockchip: vop2: Fix Null Pointer Dereference on Multiple VPs

[Michael Riesch]

Hi,

On 9/12/22 20:02, Chris Morgan wrote:
> From: Chris Morgan <macromorgan at hotmail.com>

Cc: Sascha -> any thoughts on this one?

Best regards,
Michael

> If I use more than one VP to output on an RK3566 based device I
> receive the following error (and then everything freezes):
> 
> [    0.838375] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000250
> [    0.839191] Mem abort info:
> [    0.839442]   ESR = 0x0000000096000005
> [    0.839785]   EC = 0x25: DABT (current EL), IL = 32 bits
> [    0.840256]   SET = 0, FnV = 0
> [    0.840530]   EA = 0, S1PTW = 0
> [    0.840821]   FSC = 0x05: level 1 translation fault
> [    0.841254] Data abort info:
> [    0.841512]   ISV = 0, ISS = 0x00000005
> [    0.841864]   CM = 0, WnR = 0
> [    0.842130] [0000000000000250] user address but active_mm is swapper
> [    0.842704] Internal error: Oops: 96000005 [#1] SMP
> [    0.843139] Modules linked in:
> [    0.843420] CPU: 0 PID: 37 Comm: kworker/u8:1 Not tainted 6.0.0-rc5+ #40
> [    0.844013] Hardware name: RG503 (DT)
> [    0.844343] Workqueue: events_unbound deferred_probe_work_func
> [    0.844871] pstate: 80000009 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [    0.845487] pc : __drm_crtc_init_with_planes+0x48/0x2e4
> [    0.845956] lr : drm_crtc_init_with_planes+0x68/0x94
> [    0.846399] sp : ffffffc00a7a3710
> [    0.846695] x29: ffffffc00a7a3710 x28: ffffff8000fb4080 x27: ffffffc00a7a37a0
> [    0.847332] x26: ffffffc0097d01c7 x25: ffffff8000fb44d8 x24: ffffffc0097d01c7
> [    0.847967] x23: ffffffc009311870 x22: 0000000000000000 x21: 0000000000000008
> [    0.848603] x20: ffffff80010d0800 x19: ffffff8000fb44e8 x18: 0000000000000000
> [    0.849237] x17: 08000000000000d1 x16: 0800000000000091 x15: 08000000000000c1
> [    0.849874] x14: 0000000000000000 x13: 3432564e3631564e x12: 3231564e36314742
> [    0.850509] x11: 3631475234324742 x10: 000000000000002d x9 : ffffffc008682004
> [    0.851144] x8 : 00000000006f7475 x7 : 00000000fffffff0 x6 : ffffffc00a7a37a0
> [    0.851778] x5 : ffffffc0097d01c7 x4 : ffffffc009311870 x3 : 0000000000000000
> [    0.852412] x2 : 0000000000000008 x1 : ffffff8000fb44e8 x0 : ffffff80010d0800
> [    0.853048] Call trace:
> [    0.853270]  __drm_crtc_init_with_planes+0x48/0x2e4
> [    0.853706]  drm_crtc_init_with_planes+0x68/0x94
> [    0.854118]  vop2_bind+0x89c/0x920
> [    0.854429]  component_bind_all+0x18c/0x290
> [    0.854805]  rockchip_drm_bind+0xe4/0x1f0
> [    0.855166]  try_to_bring_up_aggregate_device+0x9c/0x290
> [    0.855639]  __component_add+0x110/0x168
> [    0.855991]  component_add+0x1c/0x28
> [    0.856312]  dw_mipi_dsi_rockchip_host_attach+0x98/0x10c
> [    0.856785]  dw_mipi_dsi_host_attach+0xbc/0xd0
> [    0.857184]  mipi_dsi_attach+0x30/0x44
> [    0.857521]  devm_mipi_dsi_attach+0x2c/0x70
> [    0.857896]  ams495qa01_probe+0x2d4/0x33c
> [    0.858257]  spi_probe+0x8c/0xb8
> [    0.858550]  really_probe+0x1e0/0x3b8
> [    0.858881]  __driver_probe_device+0x16c/0x184
> [    0.859278]  driver_probe_device+0x4c/0xfc
> [    0.859646]  __device_attach_driver+0xf0/0x170
> [    0.860043]  bus_for_each_drv+0xa4/0xcc
> [    0.860389]  __device_attach+0xfc/0x1a8
> [    0.860733]  device_initial_probe+0x1c/0x28
> [    0.861108]  bus_probe_device+0x38/0x9c
> [    0.861452]  deferred_probe_work_func+0xdc/0xf0
> [    0.861855]  process_one_work+0x1b0/0x260
> [    0.862217]  process_scheduled_works+0x4c/0x50
> [    0.862614]  worker_thread+0x1f0/0x26c
> [    0.862949]  kthread+0xc4/0xd4
> [    0.863227]  ret_from_fork+0x10/0x20
> [    0.863553] Code: aa0503fa f9002bfb aa0603fb b40000a2 (b9424840)
> [    0.864095] ---[ end trace 0000000000000000 ]---
> 
> A cursory reading of the datasheet suggests it's possible to have
> simultaneous output to 2 distinct outputs. On page 13 it states:
> 
> Support two simultaneous displays(same source) in the following interfaces:
> - MIPI_DSI_TX
> - LVDS
> - HDMI
> - eDP
> 
> In order to achieve this though, I need to output to VP0 and VP1 (or
> any 2 distinct VPs really). This is so I can have the ref clock set
> to 24MHz for the HDMI and the pixel clock of the DSI panel (for the
> example above it's 33.5MHz).  Currently, only by removing this code
> block is such a thing possible, though I'm not sure if long-term
> there should only be 1 CRTC for the rk3566 (and 2 CRTCs for 3568)
> along with a max of 2 encoders for rk3566 (and 3 encoders for 3568).
> 
> Fixes: 604be85547ce ("drm/rockchip: Add VOP2 driver")
> 
> Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
> ---
>  drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 14 --------------
>  1 file changed, 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
> index e4631f515ba4..f18d7f6f9f86 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
> @@ -2289,20 +2289,6 @@ static int vop2_create_crtc(struct vop2 *vop2)
>  		struct vop2_win *win = &vop2->win[i];
>  		u32 possible_crtcs;
>  
> -		if (vop2->data->soc_id == 3566) {
> -			/*
> -			 * On RK3566 these windows don't have an independent
> -			 * framebuffer. They share the framebuffer with smart0,
> -			 * esmart0 and cluster0 respectively.
> -			 */
> -			switch (win->data->phys_id) {
> -			case ROCKCHIP_VOP2_SMART1:
> -			case ROCKCHIP_VOP2_ESMART1:
> -			case ROCKCHIP_VOP2_CLUSTER1:
> -				continue;
> -			}
> -		}
> -
>  		if (win->type == DRM_PLANE_TYPE_PRIMARY) {
>  			vp = find_vp_without_primary(vop2);
>  			if (vp) {