Hi Meng,
The only situation I could observe that is when fsl,panel was not valid...
However, I think with my patch "drm/fsl-dcu: Fix no fb check bug", this situation can be avoided completely: https://lkml.org/lkml/2015/11/18/950
With that patch applied, and a non-existing panel assigned, the DRM driver already fails at probe time gracefully: [ 0.488291] [drm] Initialized drm 1.1.0 20060810 [ 0.501576] fsl-dcu 40058000.dcu: failed to initialize mode setting
So I think that a state->fb check for NULL is not necessary at all...
Can you test my patch to see if it fixes the issue for you too?
-- Stefan
On 2015-12-23 21:28, Meng Yi wrote:
Tested-by: Meng Yi meng.yi@nxp.com
-----邮件原件----- 发件人: Dongsheng Wang [mailto:Dongsheng.Wang@freescale.com] 发送时间: Tuesday, December 01, 2015 4:16 PM 收件人: airlied@linux.ie 抄送: stefan@agner.ch; dri-devel@lists.freedesktop.org; Jianwei Wang jianwei.wang.chn@gmail.com; Yi Meng-B56799 B56799@freescale.com; Wang Dongsheng-B40534 Dongsheng.Wang@freescale.com 主题: [RESEND 1/3] drm: fsl-dcu: Fix no fb check bug
From: Jianwei Wang jianwei.wang.chn@gmail.com
For state->fb may be NULL in fsl_dcu_drm_plane_atomic_check function, if so, return -EINVAL. No need check in fsl_dcu_drm_plane_atomic_update anymore.
Signed-off-by: Jianwei Wang jianwei.wang.chn@gmail.com Signed-off-by: Yi Meng b56799@freescale.com Signed-off-by: Wang Dongsheng dongsheng.wang@freescale.com Tested-by: Stefan Agner stefan@agner.ch
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c index 51daaea..a8932a8 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c @@ -41,6 +41,9 @@ static int fsl_dcu_drm_plane_atomic_check(struct drm_plane *plane, { struct drm_framebuffer *fb = state->fb;
- if (!fb)
return -EINVAL;- switch (fb->pixel_format) { case DRM_FORMAT_RGB565: case DRM_FORMAT_RGB888:
@@ -85,9 +88,6 @@ static void fsl_dcu_drm_plane_atomic_update(struct drm_plane *plane, unsigned int alpha, bpp; int index, ret;
- if (!fb)
return;- index = fsl_dcu_drm_plane_index(plane); if (index < 0) return;
-- 2.1.0.27.g96db324