2018-07-30 06:16:58

by Satendra Singh Thakur

Subject: [PATCH] drm/kms/atomic: Improved the func drm_atomic_set_crtc_for_connector

a. Used drm_atomic_get_crtc_state instead of drm_atomic_get_new_crtc_state.
Anyway new_state and state are same, this should make no difference.
This change will make the code of this func and the func
drm_atomic_set_crtc_for_plane similar.
b. Added error checking after this func call
c. Currently conn_state->crtc is getting assigned a value at two places
We can just reduce this assignment to one

Signed-off-by: Satendra Singh Thakur <[email protected]>
---
drivers/gpu/drm/drm_atomic.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 895741e..907fb2d 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1552,16 +1552,16 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
return 0;

if (conn_state->crtc) {
- crtc_state = drm_atomic_get_new_crtc_state(conn_state->state,
+ crtc_state = drm_atomic_get_crtc_state(conn_state->state,
conn_state->crtc);
+ if (IS_ERR(crtc_state))
+ return PTR_ERR(crtc_state);

crtc_state->connector_mask &=
~(1 << drm_connector_index(conn_state->connector));

drm_connector_put(conn_state->connector);
- conn_state->crtc = NULL;
}
-
if (crtc) {
crtc_state = drm_atomic_get_crtc_state(conn_state->state, crtc);
if (IS_ERR(crtc_state))
@@ -1571,7 +1571,6 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
1 << drm_connector_index(conn_state->connector);

drm_connector_get(conn_state->connector);
- conn_state->crtc = crtc;

DRM_DEBUG_ATOMIC("Link connector state %p to [CRTC:%d:%s]\n",
conn_state, crtc->base.id, crtc->name);
@@ -1579,7 +1578,7 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
DRM_DEBUG_ATOMIC("Link connector state %p to [NOCRTC]\n",
conn_state);
}
-
+ conn_state->crtc = crtc;
return 0;
}
EXPORT_SYMBOL(drm_atomic_set_crtc_for_connector);
--
2.7.4

2018-07-30 08:01:37

by Maarten Lankhorst

Subject: Re: [PATCH] drm/kms/atomic: Improved the func drm_atomic_set_crtc_for_connector

Op 30-07-18 om 08:14 schreef Satendra Singh Thakur:
> a. Used drm_atomic_get_crtc_state instead of drm_atomic_get_new_crtc_state.
> Anyway new_state and state are same, this should make no difference.
> This change will make the code of this func and the func
> drm_atomic_set_crtc_for_plane similar.
> b. Added error checking after this func call
> c. Currently conn_state->crtc is getting assigned a value at two places
> We can just reduce this assignment to one
>
> Signed-off-by: Satendra Singh Thakur <[email protected]>
> ---
> drivers/gpu/drm/drm_atomic.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 895741e..907fb2d 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -1552,16 +1552,16 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
> return 0;
>
> if (conn_state->crtc) {
> - crtc_state = drm_atomic_get_new_crtc_state(conn_state->state,
> + crtc_state = drm_atomic_get_crtc_state(conn_state->state,
> conn_state->crtc);
> + if (IS_ERR(crtc_state))
> + return PTR_ERR(crtc_state);
The error checking is not required when using drm_atomic_get_new_crtc_state,
because the end of drm_atomic_get_connector_state() will fetch it for us.

The other place where conn_state->crtc is assigned is in drm_atomic_set_crtc_for_connector(),
which also makes sure we have the crtc_state part of the commit.

It would be a bug if we would have a conn_state without conn_state->crtc's state.
Did you hit a crash here?
> crtc_state->connector_mask &=
> ~(1 << drm_connector_index(conn_state->connector));
>
> drm_connector_put(conn_state->connector);
> - conn_state->crtc = NULL;
> }
> -
> if (crtc) {
> crtc_state = drm_atomic_get_crtc_state(conn_state->state, crtc);
> if (IS_ERR(crtc_state))
> @@ -1571,7 +1571,6 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
> 1 << drm_connector_index(conn_state->connector);
>
> drm_connector_get(conn_state->connector);
> - conn_state->crtc = crtc;
>
> DRM_DEBUG_ATOMIC("Link connector state %p to [CRTC:%d:%s]\n",
> conn_state, crtc->base.id, crtc->name);
> @@ -1579,7 +1578,7 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
> DRM_DEBUG_ATOMIC("Link connector state %p to [NOCRTC]\n",
> conn_state);
> }
> -
> + conn_state->crtc = crtc;
> return 0;
> }
> EXPORT_SYMBOL(drm_atomic_set_crtc_for_connector);

~Maarten

2018-08-03 11:51:25

by Satendra Singh Thakur

Subject: [PATCH v1] drm/kms/atomic: Improved the func drm_atomic_set_crtc_for_connector

1. Currently conn_state->crtc is getting assigned a value at two places
We can just reduce this assignment to one

Signed-off-by: Satendra Singh Thakur <[email protected]>
---
v1: Hi Mr Maarten, Thanks for the comments.
I have modified the patch suitably. Please review.

drivers/gpu/drm/drm_atomic.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 895741e..560b01c 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1559,7 +1559,6 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
~(1 << drm_connector_index(conn_state->connector));

drm_connector_put(conn_state->connector);
- conn_state->crtc = NULL;
}

if (crtc) {
@@ -1571,7 +1570,6 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
1 << drm_connector_index(conn_state->connector);

drm_connector_get(conn_state->connector);
- conn_state->crtc = crtc;

DRM_DEBUG_ATOMIC("Link connector state %p to [CRTC:%d:%s]\n",
conn_state, crtc->base.id, crtc->name);
@@ -1579,6 +1577,7 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
DRM_DEBUG_ATOMIC("Link connector state %p to [NOCRTC]\n",
conn_state);
}
+ conn_state->crtc = crtc;

return 0;
}
--
2.7.4