Hi again,
On 1/26/23 20:40, Armin Wolf wrote:
> Until now, the dell-wmi-ddv driver needs to be manually
> patched and compiled to test compatibility with unknown
> DDV WMI interface versions.
> Add a module param to allow users to force loading even
> when a unknown interface version was detected. Since this
> might cause various unwanted side effects, the module param
> is marked as unsafe.
> Also update kernel-parameters.txt.
>
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
> ---
> Documentation/admin-guide/kernel-parameters.txt | 3 +++
> drivers/platform/x86/dell/dell-wmi-ddv.c | 13 +++++++++++--
> 2 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 6cfa6e3996cf..9bbff5113427 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -1024,6 +1024,9 @@
> dell_smm_hwmon.fan_max=
> [HW] Maximum configurable fan speed.
>
> + dell_wmi_ddv.force=
> + [HW] Do not check for supported WMI interface versions.
> +
> dfltcc= [HW,S390]
> Format: { on | off | def_only | inf_only | always }
> on: s390 zlib hardware support for compression on
In my previous email I forgot to add that I have dropped this bit. I appreciate
the effort to document this parameter, but if we add documentation for all
existing parameters to Documentation/admin-guide/kernel-parameters.txt then
the file will become quite unyielding / unusable.
So in general we only add new parameters which we expect to be important for
a large group of users or necessary to debug serious problems like machines
not booting.
I realize that a bunch of parameters in there do not match this, like
e.g. dell_smm_hwmon.fan_max, these are just from older times when
there were just less parameters, so listing them all was still ok.
So I have merged this patch, but with the Documentation/admin-guide/kernel-parameters.txt
bit dropped.
Regards,
Hans
> diff --git a/drivers/platform/x86/dell/dell-wmi-ddv.c b/drivers/platform/x86/dell/dell-wmi-ddv.c
> index 58fadb74e86a..9695bf493ea6 100644
> --- a/drivers/platform/x86/dell/dell-wmi-ddv.c
> +++ b/drivers/platform/x86/dell/dell-wmi-ddv.c
> @@ -34,6 +34,10 @@
> #define DELL_EPPID_LENGTH 20
> #define DELL_EPPID_EXT_LENGTH 23
>
> +static bool force;
> +module_param_unsafe(force, bool, 0);
> +MODULE_PARM_DESC(force, "Force loading without checking for supported WMI interface versions");
> +
> enum dell_ddv_method {
> DELL_DDV_BATTERY_DESIGN_CAPACITY = 0x01,
> DELL_DDV_BATTERY_FULL_CHARGE_CAPACITY = 0x02,
> @@ -349,8 +353,13 @@ static int dell_wmi_ddv_probe(struct wmi_device *wdev, const void *context)
> return ret;
>
> dev_dbg(&wdev->dev, "WMI interface version: %d\n", version);
> - if (version < DELL_DDV_SUPPORTED_VERSION_MIN || version > DELL_DDV_SUPPORTED_VERSION_MAX)
> - return -ENODEV;
> + if (version < DELL_DDV_SUPPORTED_VERSION_MIN || version > DELL_DDV_SUPPORTED_VERSION_MAX) {
> + if (!force)
> + return -ENODEV;
> +
> + dev_warn(&wdev->dev, "Loading despite unsupported WMI interface version (%u)\n",
> + version);
> + }
>
> data = devm_kzalloc(&wdev->dev, sizeof(*data), GFP_KERNEL);
> if (!data)
> --
> 2.30.2
>
