| From 749408b6713f5525b72ed4e9763176da39cb4a05 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 2 Sep 2022 16:41:11 +0200 |
| Subject: drm/vc4: Add module dependency on hdmi-codec |
| |
| From: Maxime Ripard <maxime@cerno.tech> |
| |
| [ Upstream commit d1c0b7de4dfa5505cf7a1d6220aa72aace4435d0 ] |
| |
| The VC4 HDMI controller driver relies on the HDMI codec ASoC driver. In |
| order to set it up properly, in vc4_hdmi_audio_init(), our HDMI driver |
| will register a device matching the HDMI codec driver, and then register |
| an ASoC card using that codec. |
| |
| However, if vc4 is compiled as a module, chances are that the hdmi-codec |
| driver will be too. In such a case, the module loader will have a very |
| narrow window to load the module between the device registration and the |
| card registration. |
| |
| If it fails to load the module in time, the card registration will fail |
| with EPROBE_DEFER, and we'll abort the audio initialisation, |
| unregistering the HDMI codec device in the process. |
| |
| The next time the bind callback will be run, it's likely that we end up |
| missing that window again, effectively preventing vc4 to probe entirely. |
| |
| In order to prevent this, we can create a soft dependency of the vc4 |
| driver on the HDMI codec one so that we're sure the HDMI codec will be |
| loaded before the VC4 module is, and thus we'll never end up in the |
| previous situation. |
| |
| Fixes: 91e99e113929 ("drm/vc4: hdmi: Register HDMI codec") |
| Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> |
| Signed-off-by: Maxime Ripard <maxime@cerno.tech> |
| Link: https://patchwork.freedesktop.org/patch/msgid/20220902144111.3424560-1-maxime@cerno.tech |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/gpu/drm/vc4/vc4_drv.c | 1 + |
| 1 file changed, 1 insertion(+) |
| |
| diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c |
| index ef8fa2850ed6..d216a1fd057c 100644 |
| --- a/drivers/gpu/drm/vc4/vc4_drv.c |
| +++ b/drivers/gpu/drm/vc4/vc4_drv.c |
| @@ -397,6 +397,7 @@ module_init(vc4_drm_register); |
| module_exit(vc4_drm_unregister); |
| |
| MODULE_ALIAS("platform:vc4-drm"); |
| +MODULE_SOFTDEP("pre: snd-soc-hdmi-codec"); |
| MODULE_DESCRIPTION("Broadcom VC4 DRM Driver"); |
| MODULE_AUTHOR("Eric Anholt <eric@anholt.net>"); |
| MODULE_LICENSE("GPL v2"); |
| -- |
| 2.35.1 |
| |
