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

From: Zenghui Yu
Date: Mon Jul 06 2020 - 10:54:00 EST


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>
---
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:
--
2.19.1