Re: [External]Re: [PATCH v2] platform/x86: think-lmi: add debug_cmd

[Mark Pearson <markpearson@lenovo.com>]

Hi Hans

On 2021-08-18 3:44 a.m., Hans de Goede wrote:
> Hi,
> 
> On 8/17/21 2:15 AM, Mark Pearson wrote:
>> Many Lenovo BIOS's support the ability to send a debug command which
>> is useful for debugging and testing unreleased or early features.
>>
>> Adding support for this feature as a module parameter.
>>
>> Signed-off-by: Mark Pearson <markpearson@lenovo.com>
>> ---
>> Changes in v2:
>>   - Updated to use debug_support parameter to enable feature
>>   - remove changes to pending_reboot as that was integrated separately
>>
>>   .../testing/sysfs-class-firmware-attributes   | 11 +++
>>   drivers/platform/x86/think-lmi.c              | 80 +++++++++++++++++++
>>   drivers/platform/x86/think-lmi.h              |  1 +
>>   3 files changed, 92 insertions(+)
>>
>> diff --git a/Documentation/ABI/testing/sysfs-class-firmware-attributes b/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> index 0b43997b76e3..90fdf935aa5e 100644
>> --- a/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> +++ b/Documentation/ABI/testing/sysfs-class-firmware-attributes
>> @@ -272,3 +272,14 @@ Description:
>>   
>>   		Note that any changes to this attribute requires a reboot
>>   		for changes to take effect.
>> +
>> +What:		/sys/class/firmware-attributes/*/attributes/debug_cmd
>> +Date:		July 2021
>> +KernelVersion:	5.14
>> +Contact:	Mark Pearson <markpearson@lenovo.com>
>> +Description:
>> +		This write only attribute can be used to send debug commands to the BIOS.
>> +		This should only be used when recommended by the BIOS vendor. Vendors may
>> +		use it to enable extra debug attributes or BIOS features for testing purposes.
>> +
>> +		Note that any changes to this attribute requires a reboot for changes to take effect.
>> diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c
>> index 6cfed4427fb0..4d246bfe4907 100644
>> --- a/drivers/platform/x86/think-lmi.c
>> +++ b/drivers/platform/x86/think-lmi.c
>> @@ -20,6 +20,10 @@
>>   #include "firmware_attributes_class.h"
>>   #include "think-lmi.h"
>>   
>> +static bool debug_support;
>> +module_param(debug_support, bool, 0644);
> 
> 0644 implies the setting can be changed at runtime, but it is checked
> only at driver bind + unbind time, so this should be 0444.
Good catch - thanks!
> 
> Since the rest of the patch looks good, I've fixed this up while merging
> the patch.
Awesome - thank you!

Mark