[PATCH 20/22] drm/fsl-dcu: Use drm_fb_cma_fbdev_init/fini()

Stefan Agner stefan at agner.ch
Fri Nov 10 17:01:52 UTC 2017


On 2017-11-04 14:04, Noralf Trønnes wrote:
> Use drm_fb_cma_fbdev_init() and drm_fb_cma_fbdev_fini() which relies on
> the fact that drm_device holds a pointer to the drm_fb_helper structure.
> This means that the driver doesn't have to keep track of that.
> Also use the drm_fb_helper functions directly.

With the suspend/resume helper and this patchset applied I get:

[    0.788177] Unable to handle kernel NULL pointer dereference at
virtual address 00000008
[    0.796341] pgd = 80004000
[    0.799074] [00000008] *pgd=00000000
[    0.802687] Internal error: Oops: 5 [#1] ARM
[    0.806981] Modules linked in:
[    0.810070] CPU: 0 PID: 1 Comm: swapper Not tainted
4.14.0-rc3-00048-gea604dafe5ec-dirty #732
[    0.818635] Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
[    0.825100] task: 8e444000 task.stack: 8e442000
[    0.829673] PC is at drm_fbdev_cma_create+0x148/0x268
[    0.834747] LR is at 0x10
[    0.837388] pc : [<804867b4>]    lr : [<00000010>]    psr: 80000053
[    0.843678] sp : 8e443b98  ip : 00000000  fp : 8e443bd4
[    0.848926] r10: 8e620400  r9 : 8e623a00  r8 : 8e617240
[    0.854179] r7 : 8e617180  r6 : 000e1000  r5 : 8e443bd8  r4 :
8e620c00
[    0.860733] r3 : 00000000  r2 : 8ed00000  r1 : 00000000  r0 :
00000003
[    0.867288] Flags: Nzcv  IRQs on  FIQs off  Mode SVC_32  ISA ARM 
Segment none
[    0.874549] Control: 10c5387d  Table: 80004059  DAC: 00000051
[    0.880318] Process swapper (pid: 1, stack limit = 0x8e442208)
[    0.886177] Stack: (0x8e443b98 to 0x8e444000)
[    0.890560] 3b80:                                                    
  00000000 00000018
[    0.898782] 3ba0: 8e625240 00000003 80c39ecc 8e617180 00000018
8e620400 80c20428 00000001
[    0.907009] 3bc0: 8e6250a8 00000000 8e443c1c 8e443bd8 80485c00
80486678 00000280 000001e0
[    0.915235] 3be0: 00000280 000001e0 00000018 00000018 8e617210
8e617180 00000018 00000000
[    0.923463] 3c00: 8e617180 00000000 8e618700 00000000 8e443c34
8e443c20 80485e18 80485a30
[    0.931690] 3c20: 00000018 8e620400 8e443cfc 8e443c38 80486518
80485de8 00000000 00000000
[    0.939915] 3c40: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[    0.948133] 3c60: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[    0.956352] 3c80: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[    0.964570] 3ca0: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[    0.972790] 3cc0: 00000000 00000000 00000000 00000000 00000000
00000000 8e443d0c 8e620400
[    0.981018] 3ce0: 80c20878 8e61c810 80c208d8 00000000 8e443d0c
8e443d00 8048654c 8048637c
[    0.989245] 3d00: 8e443d2c 8e443d10 804ae0f4 80486544 8e620400
00000000 00000000 80c208d8
[    0.997472] 3d20: 8e443d64 8e443d30 8048da94 804ae070 00000000
809b0410 8e443d64 8e443d48
[    1.005699] 3d40: 8e61c810 8e4b7a10 8e4b7a00 8e620400 00000000
809b0410 8e443dcc 8e443d68
[    1.013925] 3d60: 804ae350 8048d960 9004e054 00000000 00000008
00000010 00000000 00000001
[    1.022153] 3d80: 30756364 7669645f 7869705f 8e443d00 802417c8
8023ded4 8e4b7a10 00000000
[    1.030380] 3da0: 8e4b7a18 8e4b7a10 ffffffed 80c2088c fffffdfb
80c2088c 00000000 00000000
[    1.038607] 3dc0: 8e443dec 8e443dd0 804b90b4 804ae178 8e4b7a10
80c5b410 80c5b414 00000000
[    1.046835] 3de0: 8e443e1c 8e443df0 804b7578 804b9068 00000000
8e4b7a10 80c2088c 8e4b7a44
[    1.055061] 3e00: 00000000 000000c2 80b0061c 00000007 8e443e3c
8e443e20 804b76b0 804b730c
[    1.063289] 3e20: 00000000 80c2088c 804b75f0 00000000 8e443e64
8e443e40 804b5878 804b75fc
[    1.071516] 3e40: 8e403f4c 8e4b63b0 8e6128b4 80c2088c 8e612880
80c20ee8 8e443e74 8e443e68
[    1.079743] 3e60: 804b6eb8 804b5814 8e443e9c 8e443e78 804b6930
804b6ea0 809b9bcc 8e443e88
[    1.087970] 3e80: 80c2088c 80b1b304 00000000 80b2d830 8e443eb4
8e443ea0 804b802c 804b6834
[    1.096197] 3ea0: 80c20ee8 80b1b304 8e443ecc 8e443eb8 804b9010
804b7fb8 ffffe000 80b1b304
[    1.104424] 3ec0: 8e443edc 8e443ed0 80b1b320 804b8fd4 8e443f4c
8e443ee0 8010190c 80b1b310
[    1.112651] 3ee0: 8e443f4c 8e443ef0 80134300 80b00628 8096fbd0
8096fbb0 8096fbfc 8096fb88
[    1.120878] 3f00: 80977cc4 00000006 00000006 00000000 80a351fc
809cdb30 8fdffc04 8fdffc0d
[    1.129105] 3f20: 00000000 80c37800 80c37800 80c37800 80c37800
80b38adc 000000c2 80b0061c
[    1.137332] 3f40: 8e443f94 8e443f50 80b00e88 801018cc 00000006
00000006 00000000 80b0061c
[    1.145558] 3f60: 00000000 80a351fc 00000000 00000000 80792c48
00000000 00000000 00000000
[    1.153777] 3f80: 00000000 00000000 8e443fac 8e443f98 80792c58
80b00d5c 00000000 80792c48
[    1.162004] 3fa0: 00000000 8e443fb0 80107cb0 80792c54 00000000
00000000 00000000 00000000
[    1.170230] 3fc0: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[    1.178449] 3fe0: 00000000 00000000 00000000 00000000 00000013
00000000 5aefffff 7deefbff
[    1.186662] Backtrace:
[    1.189151] [<8048666c>] (drm_fbdev_cma_create) from [<80485c00>]
(__drm_fb_helper_initial_config_and_unlock+0x1dc/0x3b8)
[    1.200164]  r10:00000000 r9:8e6250a8 r8:00000001 r7:80c20428
r6:8e620400 r5:00000018
[    1.208030]  r4:8e617180
[    1.210598] [<80485a24>] (__drm_fb_helper_initial_config_and_unlock)
from [<80485e18>] (drm_fb_helper_initial_config+0x3c/0x40)
[    1.222126]  r10:00000000 r9:8e618700 r8:00000000 r7:8e617180
r6:00000000 r5:00000018
[    1.229986]  r4:8e617180
[    1.232553] [<80485ddc>] (drm_fb_helper_initial_config) from
[<80486518>] (drm_fb_cma_fbdev_init_with_funcs+0x1a8/0x1c8)
[    1.243464]  r5:8e620400 r4:00000018
[    1.247072] [<80486370>] (drm_fb_cma_fbdev_init_with_funcs) from
[<8048654c>] (drm_fb_cma_fbdev_init+0x14/0x18)
[    1.257208]  r8:00000000 r7:80c208d8 r6:8e61c810 r5:80c20878
r4:8e620400
[    1.263951] [<80486538>] (drm_fb_cma_fbdev_init) from [<804ae0f4>]
(fsl_dcu_load+0x90/0x108)
[    1.272446] [<804ae064>] (fsl_dcu_load) from [<8048da94>]
(drm_dev_register+0x140/0x1d8)
[    1.280581]  r7:80c208d8 r6:00000000 r5:00000000 r4:8e620400
[    1.286277] [<8048d954>] (drm_dev_register) from [<804ae350>]
(fsl_dcu_drm_probe+0x1e4/0x2e4)
[    1.294854]  r9:809b0410 r8:00000000 r7:8e620400 r6:8e4b7a00
r5:8e4b7a10 r4:8e61c810
[    1.302652] [<804ae16c>] (fsl_dcu_drm_probe) from [<804b90b4>]
(platform_drv_probe+0x58/0xb8)
[    1.311222]  r10:00000000 r9:00000000 r8:80c2088c r7:fffffdfb
r6:80c2088c r5:ffffffed
[    1.319087]  r4:8e4b7a10
[    1.321653] [<804b905c>] (platform_drv_probe) from [<804b7578>]
(driver_probe_device+0x278/0x2f0)
[    1.330570]  r7:00000000 r6:80c5b414 r5:80c5b410 r4:8e4b7a10
[    1.336262] [<804b7300>] (driver_probe_device) from [<804b76b0>]
(__driver_attach+0xc0/0xc4)
[    1.344745]  r10:00000007 r9:80b0061c r8:000000c2 r7:00000000
r6:8e4b7a44 r5:80c2088c
[    1.352613]  r4:8e4b7a10 r3:00000000
[    1.356228] [<804b75f0>] (__driver_attach) from [<804b5878>]
(bus_for_each_dev+0x70/0xa4)
[    1.364449]  r7:00000000 r6:804b75f0 r5:80c2088c r4:00000000
[    1.370145] [<804b5808>] (bus_for_each_dev) from [<804b6eb8>]
(driver_attach+0x24/0x28)
[    1.378193]  r6:80c20ee8 r5:8e612880 r4:80c2088c
[    1.382845] [<804b6e94>] (driver_attach) from [<804b6930>]
(bus_add_driver+0x108/0x214)
[    1.390895] [<804b6828>] (bus_add_driver) from [<804b802c>]
(driver_register+0x80/0xfc)
[    1.398945]  r7:80b2d830 r6:00000000 r5:80b1b304 r4:80c2088c
[    1.404640] [<804b7fac>] (driver_register) from [<804b9010>]
(__platform_driver_register+0x48/0x50)
[    1.413721]  r5:80b1b304 r4:80c20ee8
[    1.417346] [<804b8fc8>] (__platform_driver_register) from
[<80b1b320>] (fsl_dcu_drm_platform_driver_init+0x1c/0x20)
[    1.427914]  r5:80b1b304 r4:ffffe000
[    1.431530] [<80b1b304>] (fsl_dcu_drm_platform_driver_init) from
[<8010190c>] (do_one_initcall+0x4c/0x170)
[    1.441241] [<801018c0>] (do_one_initcall) from [<80b00e88>]
(kernel_init_freeable+0x138/0x1c8)
[    1.449986]  r9:80b0061c r8:000000c2 r6:80b38adc r5:80c37800
r4:80c37800
[    1.456737] [<80b00d50>] (kernel_init_freeable) from [<80792c58>]
(kernel_init+0x10/0x10c)
[    1.465052]  r10:00000000 r9:00000000 r8:00000000 r7:00000000
r6:00000000 r5:80792c48
[    1.472919]  r4:00000000
[    1.475491] [<80792c48>] (kernel_init) from [<80107cb0>]
(ret_from_fork+0x14/0x24)
[    1.483093]  r5:80792c48 r4:00000000
[    1.486697] Code: e58460d8 e0823003 e58430d4 e59730ac (e5935008)
[    1.492895] ---[ end trace 95d88c85f82f6379 ]---
[    1.497604] Kernel panic - not syncing: Attempted to kill init!
exitcode=0x0000000b

I did not yet look further into this, maybe you have an idea?

--
Stefan


> 
> Cc: Stefan Agner <stefan at agner.ch>
> Cc: Alison Wang <alison.wang at freescale.com>
> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
> ---
>  drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 26 ++++++--------------------
>  drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h |  1 -
>  2 files changed, 6 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> index 1a9ee657bbac..45a44bb7a2e4 100644
> --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
> @@ -11,7 +11,6 @@
>  
>  #include <linux/clk.h>
>  #include <linux/clk-provider.h>
> -#include <linux/console.h>
>  #include <linux/io.h>
>  #include <linux/mfd/syscon.h>
>  #include <linux/mm.h>
> @@ -25,6 +24,7 @@
>  #include <drm/drmP.h>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_crtc_helper.h>
> +#include <drm/drm_fb_helper.h>
>  #include <drm/drm_fb_cma_helper.h>
>  #include <drm/drm_gem_cma_helper.h>
>  #include <drm/drm_modeset_helper.h>
> @@ -89,19 +89,15 @@ static int fsl_dcu_load(struct drm_device *dev,
> unsigned long flags)
>  			"Invalid legacyfb_depth.  Defaulting to 24bpp\n");
>  		legacyfb_depth = 24;
>  	}
> -	fsl_dev->fbdev = drm_fbdev_cma_init(dev, legacyfb_depth, 1);
> -	if (IS_ERR(fsl_dev->fbdev)) {
> -		ret = PTR_ERR(fsl_dev->fbdev);
> -		fsl_dev->fbdev = NULL;
> +	ret = drm_fb_cma_fbdev_init(dev, legacyfb_depth, 1);
> +	if (ret)
>  		goto done;
> -	}
>  
>  	return 0;
>  done:
>  	drm_kms_helper_poll_fini(dev);
>  
> -	if (fsl_dev->fbdev)
> -		drm_fbdev_cma_fini(fsl_dev->fbdev);
> +	drm_fb_cma_fbdev_fini(dev);
>  
>  	drm_mode_config_cleanup(dev);
>  	drm_irq_uninstall(dev);
> @@ -112,13 +108,10 @@ static int fsl_dcu_load(struct drm_device *dev,
> unsigned long flags)
>  
>  static void fsl_dcu_unload(struct drm_device *dev)
>  {
> -	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
> -
>  	drm_atomic_helper_shutdown(dev);
>  	drm_kms_helper_poll_fini(dev);
>  
> -	if (fsl_dev->fbdev)
> -		drm_fbdev_cma_fini(fsl_dev->fbdev);
> +	drm_fb_cma_fbdev_fini(dev);
>  
>  	drm_mode_config_cleanup(dev);
>  	drm_irq_uninstall(dev);
> @@ -147,19 +140,12 @@ static irqreturn_t fsl_dcu_drm_irq(int irq, void *arg)
>  	return IRQ_HANDLED;
>  }
>  
> -static void fsl_dcu_drm_lastclose(struct drm_device *dev)
> -{
> -	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
> -
> -	drm_fbdev_cma_restore_mode(fsl_dev->fbdev);
> -}
> -
>  DEFINE_DRM_GEM_CMA_FOPS(fsl_dcu_drm_fops);
>  
>  static struct drm_driver fsl_dcu_drm_driver = {
>  	.driver_features	= DRIVER_HAVE_IRQ | DRIVER_GEM | DRIVER_MODESET
>  				| DRIVER_PRIME | DRIVER_ATOMIC,
> -	.lastclose		= fsl_dcu_drm_lastclose,
> +	.lastclose		= drm_fb_helper_lastclose,
>  	.load			= fsl_dcu_load,
>  	.unload			= fsl_dcu_unload,
>  	.irq_handler		= fsl_dcu_drm_irq,
> diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> index 93bfb98012d4..cb87bb74cb87 100644
> --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
> @@ -191,7 +191,6 @@ struct fsl_dcu_drm_device {
>  	/*protects hardware register*/
>  	spinlock_t irq_lock;
>  	struct drm_device *drm;
> -	struct drm_fbdev_cma *fbdev;
>  	struct drm_crtc crtc;
>  	struct drm_encoder encoder;
>  	struct fsl_dcu_drm_connector connector;


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