Re: drm/msm/dpu: Correct dpu encoder spinlock initialization

From: Jeykumar Sankaran
Date: Mon Jun 24 2019 - 18:26:11 EST

On 2019-06-23 23:27, Shubhashree Dhar wrote:
dpu encoder spinlock should be initialized during dpu encoder
init instead of dpu encoder setup which is part of commit.
There are chances that vblank control uses the uninitialized
spinlock if not initialized during encoder init.
Not much can be done if someone is performing a vblank operation
before encoder_setup is done.
Can you point to the path where this lock is acquired before
the encoder_setup?

Jeykumar S.

Change-Id: I5a18b95fa47397c834a266b22abf33a517b03a4e
Signed-off-by: Shubhashree Dhar <dhar@xxxxxxxxxxxxxx>
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 5f085b5..22938c7 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -2195,8 +2195,6 @@ int dpu_encoder_setup(struct drm_device *dev, struct
drm_encoder *enc,
if (ret)
goto fail;

- spin_lock_init(&dpu_enc->enc_spinlock);
atomic_set(&dpu_enc->frame_done_timeout, 0);
dpu_encoder_frame_done_timeout, 0);
@@ -2250,6 +2248,7 @@ struct drm_encoder *dpu_encoder_init(struct
drm_device *dev,

drm_encoder_helper_add(&dpu_enc->base, &dpu_encoder_helper_funcs);

+ spin_lock_init(&dpu_enc->enc_spinlock);
dpu_enc->enabled = false;

return &dpu_enc->base;

Jeykumar S