[Intel-gfx] [PATCH 2/2] drm/i915/guc: Turn on GuC/HuC auto mode

[Michal Wajdeczko]

On Tue, 09 Jul 2019 16:17:02 +0200, Joonas Lahtinen
<joonas.lahtinen at linux.intel.com> wrote:

> Better subject would be: "Enable HuC (through GuC) on supported  
> platforms"

Such subject sounds better, but on one hand it does not reflect real
code change (since we are not explicitly enabling HuC, but instead we
are just letting the driver enable GuC/HuC to whatever mode it decides),
but on other hand this is what actual outcome of the change is (as i915
currently enables GuC loading with HuC authentication on every platform
where corresponding firmwares are defined/available, and nothing more).

Please confirm if you still opt-in to use your subject.

>
> Quoting Michal Wajdeczko (2019-07-03 14:36:40)
>> GuC firmware is now mature, so let it run by default.
>
> That's bit of a misleading statement (in more than one way).

It's mature enough to perform HuC authentication, and we
don't expect more from it ;)

>
> "Enable loading HuC firmware (through GuC) to unlock
> advanced video codecs on supported platforms.
>
> GuC firmware is required to authenticate the HuC firmware,
> which is a requirement for it to operate."

To some extend this duplicates existing "DOC: HuC Firmware"
Do we need to repeat that again here?

>
> Has the most recent firmware been merged to linux-firmware and
> is it present in our CI systems?

My understanding is: No and Yes.
Maybe Anusha can provide more details here.

>
> It would also be good to list what kind of tests have been run
> to ensure that there are no regressions,

I'm afraid on IGT level we don't have HuC tests.
But media team was using modparam override to force GuC/HuC for
a while, Tony do you have such test list/results handy?

> and which platforms
> this change affects.

This change affects all platforms where we have GuC/HuC firmwares
defined, so: SKL, BXT, KBL, CFL, ICL.

Note that we'll still have possibility to tweak that inside
driver, as auto mode is just moving responsibility what can
be enabled from the user to the i915.

>
> Regards, Joonas
>
>> Note that today GuC is only used for HuC authentication.
>>
>> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
>> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
>> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>> ---
>>  drivers/gpu/drm/i915/i915_params.h | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_params.h  
>> b/drivers/gpu/drm/i915/i915_params.h
>> index d29ade3b7de6..5736c55694fe 100644
>> --- a/drivers/gpu/drm/i915/i915_params.h
>> +++ b/drivers/gpu/drm/i915/i915_params.h
>> @@ -54,7 +54,7 @@ struct drm_printer;
>>         param(int, disable_power_well, -1) \
>>         param(int, enable_ips, 1) \
>>         param(int, invert_brightness, 0) \
>> -       param(int, enable_guc, 0) \
>> +       param(int, enable_guc, -1) \
>>         param(int, guc_log_level, -1) \
>>         param(char *, guc_firmware_path, NULL) \
>>         param(char *, huc_firmware_path, NULL) \
>> --
>> 2.19.2