[Intel-gfx] [PATCH v4 1/3] drm/i915/gvt: Add gvt_debug in i915_params for GVT-g log classification

[Shuo Liu]

On Tue 19.Sep'17 at 10:22:16 +0100, Chris Wilson wrote:
>Quoting Shuo Liu (2017-09-19 08:54:43)
>> Signed-off-by: Shuo Liu <shuo.a.liu at intel.com>
>> ---
>>  drivers/gpu/drm/i915/i915_params.c | 13 +++++++++++++
>>  drivers/gpu/drm/i915/i915_params.h |  1 +
>>  2 files changed, 14 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
>> index 8ab003d..ceeae1d 100644
>> --- a/drivers/gpu/drm/i915/i915_params.c
>> +++ b/drivers/gpu/drm/i915/i915_params.c
>> @@ -65,6 +65,7 @@ struct i915_params i915 __read_mostly = {
>>         .inject_load_failure = 0,
>>         .enable_dpcd_backlight = false,
>>         .enable_gvt = false,
>> +       .debug_gvt = 0,
>>  };
>>
>>  module_param_named(modeset, i915.modeset, int, 0400);
>> @@ -257,3 +258,15 @@ struct i915_params i915 __read_mostly = {
>>  module_param_named(enable_gvt, i915.enable_gvt, bool, 0400);
>>  MODULE_PARM_DESC(enable_gvt,
>>         "Enable support for Intel GVT-g graphics virtualization host support(default:false)");
>> +
>> +module_param_named(debug_gvt, i915.debug_gvt, int, 0600);
>> +MODULE_PARM_DESC(debug_gvt, "Enable GVT-g debug output, where each bit enables a category.\n"
>> +               "        Bit 0 (0x01) will enable CORE messages (GVT-g core message)\n"
>> +               "        Bit 1 (0x02) will enable IRQ messages (GVT-g interrupt message)\n"
>> +               "        Bit 2 (0x04) will enable MM messages (GVT-g memory management message)\n"
>> +               "        Bit 3 (0x08) will enable MMIO messages (GVT-g MMIO message)\n"
>> +               "        Bit 4 (0x10) will enable DPY messages (GVT-g display message)\n"
>> +               "        Bit 5 (0x20) will enable EL messages (GVT-g execlist message)\n"
>> +               "        Bit 6 (0x40) will enable SCHED messages (GVT-g schedule message)\n"
>> +               "        Bit 7 (0x80) will enable RENDER messages (GVT-g render message)\n"
>> +               "        Bit 8 (0x100) will enable CMD messages (GVT-g command message)");
>> diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
>> index ac84470..cd29c78 100644
>> --- a/drivers/gpu/drm/i915/i915_params.h
>> +++ b/drivers/gpu/drm/i915/i915_params.h
>> @@ -54,6 +54,7 @@
>>         func(int, edp_vswing); \
>>         func(int, reset); \
>>         func(unsigned int, inject_load_failure); \
>> +       func(int, debug_gvt); \
>>         /* leave bools at the end to not create holes */ \
>>         func(bool, alpha_support); \
>>         func(bool, enable_cmd_parser); \
>
>Note that you are not forced to use i915_params. If you have gvt only
>module options that you don't want exposed outside of gvt, just create
>them within gvt.
Have talked this with Zhenyu, his suggestion is put params together as
gvt is in i915 module.
>
>Having said that, I would strongly advise against having module options,
>and I would advise you to go the dyndebug route instead of copying a
>rectangular wheel.
Thanks Chris. dyndebug might be an option. The disadvantage of dyndebug
is complicated to use, expecially in bootup debugging (add a long
cmdline to enable interesting messages). Module option is
straightforward. Zhenyu, any comments on this?

Thanks
Shuo
>-Chris