Hi,

sorry for letting these patches sit around for so long. I'd say that if you waited for a week or two without further responses, it's ok to ping people.

Am 11.04.20 um 08:25 schrieb Tian Tao:

code refactoring for hibmc_drv_vdac.c, no actual function changes.

v2: remove the debug message.

Signed-off-by: Tian Tao tiantao6@hisilicon.com Reviewed-by: Joe Perches joe@perches.com

---

drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c | 50 +++++++----------------- 1 file changed, 14 insertions(+), 36 deletions(-)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c index 678ac2e..077b7996 100644 --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c @@ -52,32 +52,6 @@ static const struct drm_connector_funcs hibmc_connector_funcs = { .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, };

-static struct drm_connector * -hibmc_connector_init(struct hibmc_drm_private *priv) -{

• struct drm_device *dev = priv->dev;
• struct drm_connector *connector;
• int ret;
• connector = devm_kzalloc(dev->dev, sizeof(*connector), GFP_KERNEL);
• if (!connector) {

• DRM_ERROR("failed to alloc memory when init connector\n");
  

• return ERR_PTR(-ENOMEM);
  

• }
• ret = drm_connector_init(dev, connector,

• 		 &hibmc_connector_funcs,
  

• 		 DRM_MODE_CONNECTOR_VGA);
  

• if (ret) {

• DRM_ERROR("failed to init connector: %d\n", ret);
  

• return ERR_PTR(ret);
  

• }
• drm_connector_helper_add(connector,

• 		 &hibmc_connector_helper_funcs);
  

• return connector;

-}

static void hibmc_encoder_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode, struct drm_display_mode *adj_mode) @@ -109,18 +83,9 @@ int hibmc_vdac_init(struct hibmc_drm_private *priv) struct drm_connector *connector; int ret;

• connector = hibmc_connector_init(priv);
• if (IS_ERR(connector)) {

• DRM_ERROR("failed to create connector: %ld\n",
  

• 	  PTR_ERR(connector));
  

• return PTR_ERR(connector);
  

• }
• encoder = devm_kzalloc(dev->dev, sizeof(*encoder), GFP_KERNEL);
• if (!encoder) {

• DRM_ERROR("failed to alloc memory when init encoder\n");
  

• if (!encoder) return -ENOMEM;

• }

  encoder->possible_crtcs = 0x1; ret = drm_encoder_init(dev, encoder, &hibmc_encoder_funcs,

@@ -131,6 +96,19 @@ int hibmc_vdac_init(struct hibmc_drm_private *priv) }

drm_encoder_helper_add(encoder, &hibmc_encoder_helper_funcs);

• connector = devm_kzalloc(dev->dev, sizeof(*connector), GFP_KERNEL);

Overall, the patch seems correct, expect for this line. DRM data structures should now be allocated with drmm_kzalloc() in drm_managed.h. It was added recently.

With devm_kzalloc(), the memory will be released when the HW device goes away. If userspace still holds a reference, the driver can segfault. Using drmm_kzalloc() delays the release until the memory is really unused.

However, hibmc's modesetting pipeline appears to be always the same. I think you should consider embedding connector and encoder (and crtc) in struct hibmc_drm_private. Would make the code simpler and more robust.

Best regards Thomas

• if (!connector)

• return -ENOMEM;
  

• ret = drm_connector_init(dev, connector, &hibmc_connector_funcs,

• 		 DRM_MODE_CONNECTOR_VGA);
  

• if (ret) {

• DRM_ERROR("failed to init connector: %d\n", ret);
  

• return ret;
  

• }

• drm_connector_helper_add(connector, &hibmc_connector_helper_funcs);

• drm_connector_attach_encoder(connector, encoder);

  return 0;