Hi Jammy Am 25.05.23 um 03:29 schrieb Jammy Huang:
If we switch display and update cursor together, it could lead to modeset failed because of concurrent access to IO registers.Add lock protection in DP's edid access to avoid this problem. Signed-off-by: Jammy Huang <jammy_hu...@aspeedtech.com> --- v2 changes: - Fix build error since new struct ast_device is used. --- drivers/gpu/drm/ast/ast_mode.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index 36374828f6c8..9fcbf540d6fc 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1647,6 +1647,8 @@ static int ast_dp501_output_init(struct ast_device *ast) static int ast_astdp_connector_helper_get_modes(struct drm_connector *connector) { void *edid; + struct drm_device *dev = connector->dev; + struct ast_device *ast = to_ast_device(dev);int succ;int count; @@ -1655,10 +1657,18 @@ static int ast_astdp_connector_helper_get_modes(struct drm_connector *connector) if (!edid) goto err_drm_connector_update_edid_property;+ /*+ * Protect access to I/O registers from concurrent modesetting + * by acquiring the I/O-register lock. + */ + mutex_lock(&ast->ioregs_lock); + succ = ast_astdp_read_edid(connector->dev, edid); if (succ < 0) goto err_kfree;+ mutex_unlock(&ast->ioregs_lock);+ drm_connector_update_edid_property(connector, edid); count = drm_add_edid_modes(connector, edid); kfree(edid); @@ -1666,6 +1676,7 @@ static int ast_astdp_connector_helper_get_modes(struct drm_connector *connector) return count;err_kfree:
This label needs to be named 'err_mutex_unlock' please. With that fixed, you can add
Reviewed-by: Thomas Zimmermann <tzimmerm...@suse.de> Best regards Thomas
+ mutex_unlock(&ast->ioregs_lock);
kfree(edid);
err_drm_connector_update_edid_property:
drm_connector_update_edid_property(connector, NULL);
base-commit: 933174ae28ba72ab8de5b35cb7c98fc211235096
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)
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