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| author | Thomas Zimmermann <tzimmermann@suse.de> | 2021-12-06 12:11:23 +0300 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2021-12-16 14:29:22 +0300 |
| commit | 55dc449a7c60d3df5a8f0b71bbae9d5173c864f5 (patch) | |
| tree | 0229059aff4fcbe2196f73cd9797f01c926b4059 /drivers/gpu/drm/ast | |
| parent | d619f38c015fd7cf79af5cd34265d5b9247a00f0 (diff) | |
| download | linux-55dc449a7c60d3df5a8f0b71bbae9d5173c864f5.tar.xz | |
drm/ast: Handle failed I2C initialization gracefully
I2C initialization is allowed to fail. In this case, create a connector
without DDC adapter. The current code would dereference a NULL pointer.
Reading the modes from the connector is supposed to work without I2C
adapter. Add the respective test.
v2:
* init edid to NULL to avoid uninitialized read (Dan)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206091125.29501-2-tzimmermann@suse.de
Diffstat (limited to 'drivers/gpu/drm/ast')
| -rw-r--r-- | drivers/gpu/drm/ast/ast_mode.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index 1e30eaeb0e1b..692e7a3b3555 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1210,9 +1210,9 @@ static int ast_get_modes(struct drm_connector *connector) { struct ast_connector *ast_connector = to_ast_connector(connector); struct ast_private *ast = to_ast_private(connector->dev); - struct edid *edid; - int ret; + struct edid *edid = NULL; bool flags = false; + int ret; if (ast->tx_chip_type == AST_TX_DP501) { ast->dp501_maxclk = 0xff; @@ -1226,7 +1226,7 @@ static int ast_get_modes(struct drm_connector *connector) else kfree(edid); } - if (!flags) + if (!flags && ast_connector->i2c) edid = drm_get_edid(connector, &ast_connector->i2c->adapter); if (edid) { drm_connector_update_edid_property(&ast_connector->base, edid); @@ -1332,10 +1332,13 @@ static int ast_connector_init(struct drm_device *dev) if (!ast_connector->i2c) drm_err(dev, "failed to add ddc bus for connector\n"); - drm_connector_init_with_ddc(dev, connector, - &ast_connector_funcs, - DRM_MODE_CONNECTOR_VGA, - &ast_connector->i2c->adapter); + if (ast_connector->i2c) + drm_connector_init_with_ddc(dev, connector, &ast_connector_funcs, + DRM_MODE_CONNECTOR_VGA, + &ast_connector->i2c->adapter); + else + drm_connector_init(dev, connector, &ast_connector_funcs, + DRM_MODE_CONNECTOR_VGA); drm_connector_helper_add(connector, &ast_connector_helper_funcs); |