Re: [PATCH] drm/hisilicon/hibmc: Move drm_fbdev_generic_setup() down to avoid the splat

From: Thomas Zimmermann
Date: Mon Jul 06 2020 - 13:03:50 EST


Hi

Am 06.07.20 um 16:47 schrieb Zenghui Yu:
> The HiSilicon hibmc driver triggers a splat at boot time as below
>
> [ 14.137806] ------------[ cut here ]------------
> [ 14.142405] hibmc-drm 0000:0a:00.0: Device has not been registered.
> [ 14.148661] WARNING: CPU: 0 PID: 496 at drivers/gpu/drm/drm_fb_helper.c:2233 drm_fbdev_generic_setup+0x15c/0x1b8
> [ 14.158787] [...]
> [ 14.278307] Call trace:
> [ 14.280742] drm_fbdev_generic_setup+0x15c/0x1b8
> [ 14.285337] hibmc_pci_probe+0x354/0x418
> [ 14.289242] local_pci_probe+0x44/0x98
> [ 14.292974] work_for_cpu_fn+0x20/0x30
> [ 14.296708] process_one_work+0x1c4/0x4e0
> [ 14.300698] worker_thread+0x2c8/0x528
> [ 14.304431] kthread+0x138/0x140
> [ 14.307646] ret_from_fork+0x10/0x18
> [ 14.311205] ---[ end trace a2000ec2d838af4d ]---
>
> This turned out to be due to the fbdev device hasn't been registered when
> drm_fbdev_generic_setup() is invoked. Let's fix the splat by moving it down
> after drm_dev_register() which will follow the "Display driver example"
> documented by commit de99f0600a79 ("drm/drv: DOC: Add driver example
> code").
>
> Signed-off-by: Zenghui Yu <yuzenghui@xxxxxxxxxx>

Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

> ---
> drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> index a6fd0c29e5b8..544b9993c99e 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> @@ -307,8 +307,6 @@ static int hibmc_load(struct drm_device *dev)
> /* reset all the states of crtc/plane/encoder/connector */
> drm_mode_config_reset(dev);
>
> - drm_fbdev_generic_setup(dev, dev->mode_config.preferred_depth);
> -
> return 0;
>
> err:
> @@ -355,6 +353,9 @@ static int hibmc_pci_probe(struct pci_dev *pdev,
> ret);
> goto err_unload;
> }
> +
> + drm_fbdev_generic_setup(dev, dev->mode_config.preferred_depth);
> +
> return 0;
>
> err_unload:
>

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 NÃrnberg, Germany
(HRB 36809, AG NÃrnberg)
GeschÃftsfÃhrer: Felix ImendÃrffer

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