Re: [PATCH 17/34] greybus: arche-ctrl: move device table to its right location

Alex Elder
2024-04-30T23:41:46Z

On 4/3/24 3:06 AM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> The arche-ctrl has two platform drivers and three of_device_id tables,
> but one table is only used for the the module loader, while the other
> two seem to be associated with their drivers.
>
> This leads to a W=1 warning when the driver is built-in:
>
> drivers/staging/greybus/arche-platform.c:623:34: error: 'arche_combined_id' defined but not used [-Werror=unused-const-variable=]
> 623 | static const struct of_device_id arche_combined_id[] = {
>
> Drop the extra table and register both tables that are actually
> used as the ones for the module loader instead.

So what I see is that this commit added arche_combined_id[]:
1e5dd1f8279a8 greybus: arche-platform: merge arche-apb-ctrl and
arche-platform

That moved the arche_apb_ctrl_device_driver struct and some other
associated bits out of arche-apb-ctrl.c and into arche-platform.c.
It *kept* arche_platform_of_match[] as the of_match_table for
arche_platform_device_driver, but defined arche_combined_id[] and
declared it for modalias to indicate both drivers were implemented
in the single kernel module.

The later commit (the one you references in "Fixes") then moved
the arche_apb_ctrl_device_driver etc. back to arche-apb-ctrl.c.
That commit did *not* use MODULE_DEVICE_TABLE() to declare
arche_apb_ctrl_of_match[] for modalias. And it simply kept the
(no longer correct) arche_combined_id[] table to be used by the
arche_platform_device_driver.

So your fix:
- Declares for modalias that arche_apb_ctrl_of_match[] is the
of_match_table for arche_apb_ctrl_device_driver.
- Declares for modalias that arche_platform_of_match[] is the
of_match_table for arche_platform_device_driver.
- Gets rid of arche_combined_id[], which is no longer used.

In short: looks good to me.

Reviewed-by: Alex Elder <elder@linaro.org>

>
> Fixes: 7b62b61c752a ("greybus: arche-ctrl: Don't expose driver internals to arche-platform driver")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> drivers/staging/greybus/arche-apb-ctrl.c | 1 +
> drivers/staging/greybus/arche-platform.c | 9 +--------
> 2 files changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/staging/greybus/arche-apb-ctrl.c b/drivers/staging/greybus/arche-apb-ctrl.c
> index 8541995008da..aa6f266b62a1 100644
> --- a/drivers/staging/greybus/arche-apb-ctrl.c
> +++ b/drivers/staging/greybus/arche-apb-ctrl.c
> @@ -466,6 +466,7 @@ static const struct of_device_id arche_apb_ctrl_of_match[] = {
> { .compatible = "usbffff,2", },
> { },
> };
> +MODULE_DEVICE_TABLE(of, arche_apb_ctrl_of_match);
>
> static struct platform_driver arche_apb_ctrl_device_driver = {
> .probe = arche_apb_ctrl_probe,
> diff --git a/drivers/staging/greybus/arche-platform.c b/drivers/staging/greybus/arche-platform.c
> index 891b75327d7f..b33977ccd527 100644
> --- a/drivers/staging/greybus/arche-platform.c
> +++ b/drivers/staging/greybus/arche-platform.c
> @@ -619,14 +619,7 @@ static const struct of_device_id arche_platform_of_match[] = {
> { .compatible = "google,arche-platform", },
> { },
> };
> -
> -static const struct of_device_id arche_combined_id[] = {
> - /* Use PID/VID of SVC device */
> - { .compatible = "google,arche-platform", },
> - { .compatible = "usbffff,2", },
> - { },
> -};
> -MODULE_DEVICE_TABLE(of, arche_combined_id);
> +MODULE_DEVICE_TABLE(of, arche_platform_of_match);
>
> static struct platform_driver arche_platform_device_driver = {
> .probe = arche_platform_probe,