On 4/20/22 14:21, Thomas Zimmermann wrote:
Hi
Am 20.04.22 um 14:02 schrieb Javier Martinez Canillas:
Hello Thomas,
On 4/20/22 13:08, Thomas Zimmermann wrote:
[snip]
--- a/drivers/gpu/drm/bridge/synopsys/Kconfig +++ b/drivers/gpu/drm/bridge/synopsys/Kconfig @@ -1,6 +1,8 @@ # SPDX-License-Identifier: GPL-2.0-only config DRM_DW_HDMI tristate
- select DRM_DISPLAY_HDMI_HELPER
- select DRM_DISPLAY_HELPER select DRM_KMS_HELPER select REGMAP_MMIO select CEC_CORE if CEC_NOTIFIER
[snip]
+config DRM_DISPLAY_HDMI_HELPER
- bool
- select DRM_DISPLAY_HELPER
- help
DRM display helpers for HDMI.Maybe you mentioned already when we discussed it in v1, but could you please remember me why we need to select both symbols for the drivers, even when DRM_DISPLAY_HELPER is already selected here ?
Or are select operations not transitive ?
DRM_DISPLAY_HELPER enables the module itself. It's tristate. DRM_DISPLAY_HDMI_HELPER, DRM_DISPLAY_DP_HELPER, etc are the individual features of the helper module. Each is a boolean. Drivers can enable them according to their needs. This split allows linking correctly in all cases, even if some drivers are built-in and others are modules. This didn't always work with the original patches.
Right, but that wasn't my question. I wondered why for example DRM_DW_HDMI Kconfig needs to select both DRM_DISPLAY_HDMI_HELPER and DRM_DISPLAY_HELPER since DRM_DISPLAY_HDMI_HELPER already selects DRM_DISPLAY_HELPER.