[PATCH] drm/fb-helper: generic: Call drm_client_add() after setup is done

[Noralf Trønnes]

Den 02.04.2019 09.55, skrev Daniel Vetter:
> On Mon, Apr 01, 2019 at 04:13:58PM +0200, Noralf Trønnes wrote:
>> Hotplug can happen while drm_fbdev_generic_setup() is running so move
>> drm_client_add() call after setup is done to avoid
>> drm_fbdev_client_hotplug() running in two threads at the same time.
>>
>> Fixes: 9060d7f49376 ("drm/fb-helper: Finish the generic fbdev emulation")
>> Reported-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
> 
> Not sure we even want a cc: stable on this, things could go boom. I guess
> we could backport once there's a bug report, up to you.
> 
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Thanks, applied with cc stable.

Noralf.

> 
>> ---
>>  drivers/gpu/drm/drm_fb_helper.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
>> index 03749a24e4dd..601b17310411 100644
>> --- a/drivers/gpu/drm/drm_fb_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>> @@ -3317,8 +3317,6 @@ int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
>>  		return ret;
>>  	}
>>  
>> -	drm_client_add(&fb_helper->client);
>> -
>>  	if (!preferred_bpp)
>>  		preferred_bpp = dev->mode_config.preferred_depth;
>>  	if (!preferred_bpp)
>> @@ -3329,6 +3327,8 @@ int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
>>  	if (ret)
>>  		DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
>>  
>> +	drm_client_add(&fb_helper->client);
>> +
>>  	return 0;
>>  }
>>  EXPORT_SYMBOL(drm_fbdev_generic_setup);
>> -- 
>> 2.20.1
>>
>