On Tue, Feb 23, 2021 at 12:26:28PM +0100, Hans Verkuil wrote:
> The rc-cec keymap is unusual in that it can't be built as a module,
> instead it is registered directly in rc-main.c if CONFIG_MEDIA_CEC_RC
> is set. This is because it can be called from drm_dp_cec_set_edid() via
> cec_register_adapter() in an asynchronous context, and it is not
> allowed to use request_module() to load rc-cec.ko in that case. Trying to
> do so results in a 'WARN_ON_ONCE(wait && current_is_async())'.
>
> Since this keymap is only used if CONFIG_MEDIA_CEC_RC is set, we
> just compile this keymap into the rc-core module and never as a
> separate module.
>
> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
> Fixes: 2c6d1fffa1d9 (drm: add support for DisplayPort CEC-Tunneling-over-AUX)
> Reported-by: Hans de Goede <hdegoede@xxxxxxxxxx>
This is correct. The patch isn't not going to win any beauty prizes, but
I haven't had any bright ideas of how to do this in a nicer way.
Thanks for writing the patch.
Acked-by: Sean Young <sean@xxxxxxxx>
> ---
> Change since v1:
> Fix copy-and-paste error: rc_core_exit() called rc_map_register() instead
> of rc_map_unregister().
> ---
> diff --git a/drivers/media/rc/Makefile b/drivers/media/rc/Makefile
> index 5bb2932ab119..ff6a8fc4c38e 100644
> --- a/drivers/media/rc/Makefile
> +++ b/drivers/media/rc/Makefile
> @@ -5,6 +5,7 @@ obj-y += keymaps/
> obj-$(CONFIG_RC_CORE) += rc-core.o
> rc-core-y := rc-main.o rc-ir-raw.o
> rc-core-$(CONFIG_LIRC) += lirc_dev.o
> +rc-core-$(CONFIG_MEDIA_CEC_RC) += keymaps/rc-cec.o
> rc-core-$(CONFIG_BPF_LIRC_MODE2) += bpf-lirc.o
> obj-$(CONFIG_IR_NEC_DECODER) += ir-nec-decoder.o
> obj-$(CONFIG_IR_RC5_DECODER) += ir-rc5-decoder.o
> diff --git a/drivers/media/rc/keymaps/Makefile b/drivers/media/rc/keymaps/Makefile
> index b252a1d2ebd6..cc6662e1903f 100644
> --- a/drivers/media/rc/keymaps/Makefile
> +++ b/drivers/media/rc/keymaps/Makefile
> @@ -21,7 +21,6 @@ obj-$(CONFIG_RC_MAP) += rc-adstech-dvb-t-pci.o \
> rc-behold.o \
> rc-behold-columbus.o \
> rc-budget-ci-old.o \
> - rc-cec.o \
> rc-cinergy-1400.o \
> rc-cinergy.o \
> rc-d680-dmb.o \
> diff --git a/drivers/media/rc/keymaps/rc-cec.c b/drivers/media/rc/keymaps/rc-cec.c
> index 3e3bd11092b4..068e22aeac8c 100644
> --- a/drivers/media/rc/keymaps/rc-cec.c
> +++ b/drivers/media/rc/keymaps/rc-cec.c
> @@ -1,5 +1,15 @@
> // SPDX-License-Identifier: GPL-2.0-or-later
> /* Keytable for the CEC remote control
> + *
> + * This keymap is unusual in that it can't be built as a module,
> + * instead it is registered directly in rc-main.c if CONFIG_MEDIA_CEC_RC
> + * is set. This is because it can be called from drm_dp_cec_set_edid() via
> + * cec_register_adapter() in an asynchronous context, and it is not
> + * allowed to use request_module() to load rc-cec.ko in that case.
> + *
> + * Since this keymap is only used if CONFIG_MEDIA_CEC_RC is set, we
> + * just compile this keymap into the rc-core module and never as a
> + * separate module.
> *
> * Copyright (c) 2015 by Kamil Debski
> */
> @@ -152,7 +162,7 @@ static struct rc_map_table cec[] = {
> /* 0x77-0xff: Reserved */
> };
>
> -static struct rc_map_list cec_map = {
> +struct rc_map_list cec_map = {
> .map = {
> .scan = cec,
> .size = ARRAY_SIZE(cec),
> @@ -160,19 +170,3 @@ static struct rc_map_list cec_map = {
> .name = RC_MAP_CEC,
> }
> };
> -
> -static int __init init_rc_map_cec(void)
> -{
> - return rc_map_register(&cec_map);
> -}
> -
> -static void __exit exit_rc_map_cec(void)
> -{
> - rc_map_unregister(&cec_map);
> -}
> -
> -module_init(init_rc_map_cec);
> -module_exit(exit_rc_map_cec);
> -
> -MODULE_LICENSE("GPL");
> -MODULE_AUTHOR("Kamil Debski");
> diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
> index 1fd62c1dac76..4768b1e9ffd1 100644
> --- a/drivers/media/rc/rc-main.c
> +++ b/drivers/media/rc/rc-main.c
> @@ -163,6 +163,10 @@ static struct rc_map_list empty_map = {
> }
> };
>
> +#ifdef CONFIG_MEDIA_CEC_RC
> +extern struct rc_map_list cec_map;
> +#endif
> +
> /**
> * scancode_to_u64() - converts scancode in &struct input_keymap_entry
> * @ke: keymap entry containing scancode to be converted.
> @@ -2069,6 +2073,9 @@ static int __init rc_core_init(void)
>
> led_trigger_register_simple("rc-feedback", &led_feedback);
> rc_map_register(&empty_map);
> +#ifdef CONFIG_MEDIA_CEC_RC
> + rc_map_register(&cec_map);
> +#endif
>
> return 0;
> }
> @@ -2078,6 +2085,9 @@ static void __exit rc_core_exit(void)
> lirc_dev_exit();
> class_unregister(&rc_class);
> led_trigger_unregister_simple(led_feedback);
> +#ifdef CONFIG_MEDIA_CEC_RC
> + rc_map_unregister(&cec_map);
> +#endif
> rc_map_unregister(&empty_map);
> }
