[PATCH] drm/amd/display: add HDCP caps debugfs

[Harry Wentland]

On 2020-02-24 4:51 p.m., Bhawanpreet Lakha wrote:
> 
> On 2020-02-24 4:15 p.m., Harry Wentland wrote:
>>
>> On 2020-02-24 2:55 p.m., Bhawanpreet Lakha wrote:
>>> Add debugfs to get HDCP capability. This is also useful for
>>> kms_content_protection igt test.
>>>
>>> Use:
>>>     cat /sys/kernel/debug/dri/0/DP-1/hdcp_sink_capability
>>>     cat /sys/kernel/debug/dri/0/HDMI-A-1/hdcp_sink_capability
>>>
>>> Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.com>
>>> ---
>>>   .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 61 +++++++++++++++++++
>>>   1 file changed, 61 insertions(+)
>>>
>>> diff --git
>>> a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
>>> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
>>> index ead5c05eec92..52982c8c871f 100644
>>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
>>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
>>> @@ -815,6 +815,44 @@ static int vrr_range_show(struct seq_file *m,
>>> void *data)
>>>       return 0;
>>>   }
>>>   +#ifdef CONFIG_DRM_AMD_DC_HDCP
>>> +/*
>>> + * Returns the HDCP capability of the Display (1.4 for now).
>>> + *
>>> + * NOTE* Not all HDMI displays report their HDCP caps even when they
>>> are capable.
>>> + * Since its rare for a display to not be HDCP 1.4 capable, we set
>>> HDMI as always capable.
>>> + *
>>> + * Example usage: cat /sys/kernel/debug/dri/0/DP-1/hdcp_sink_capability
>>> + *        or cat /sys/kernel/debug/dri/0/HDMI-A-1/hdcp_sink_capability
>>> + */
>>> +static int hdcp_sink_capability_show(struct seq_file *m, void *data)
>>> +{
>>> +    struct drm_connector *connector = m->private;
>>> +    struct amdgpu_dm_connector *aconnector =
>>> to_amdgpu_dm_connector(connector);
>>> +    bool hdcp_cap, hdcp2_cap;
>>> +
>>> +    if (connector->status != connector_status_connected)
>>> +        return -ENODEV;
>>> +
>>> +    seq_printf(m, "%s:%d HDCP version: ", connector->name,
>>> connector->base.id);
>>> +
>>> +    hdcp_cap = dc_link_is_hdcp14(aconnector->dc_link);
>>> +    hdcp2_cap = dc_link_is_hdcp22(aconnector->dc_link);
>>> +
>>> +
>>> +    if (hdcp_cap)
>>> +        seq_printf(m, "%s ", "HDCP1.4");
>>> +    if (hdcp2_cap)
>>> +        seq_printf(m, "%s ", "HDCP2.2");
>>> +
>>> +    if (!hdcp_cap && !hdcp2_cap)
>>> +        seq_printf(m, "%s ", "None");
>>> +
>>> +    seq_puts(m, "\n");
>>> +
>>> +    return 0;
>>> +}
>>> +#endif
>>>   /* function description
>>>    *
>>>    * generic SDP message access for testing
>>> @@ -940,6 +978,9 @@ static ssize_t dp_dpcd_data_read(struct file *f,
>>> char __user *buf,
>>>   DEFINE_SHOW_ATTRIBUTE(dmub_tracebuffer);
>>>   DEFINE_SHOW_ATTRIBUTE(output_bpc);
>>>   DEFINE_SHOW_ATTRIBUTE(vrr_range);
>>> +#ifdef CONFIG_DRM_AMD_DC_HDCP
>>> +DEFINE_SHOW_ATTRIBUTE(hdcp_sink_capability);
>>> +#endif
>>>     static const struct file_operations dp_link_settings_debugfs_fops
>>> = {
>>>       .owner = THIS_MODULE,
>>> @@ -995,12 +1036,23 @@ static const struct {
>>>           {"test_pattern", &dp_phy_test_pattern_fops},
>>>           {"output_bpc", &output_bpc_fops},
>>>           {"vrr_range", &vrr_range_fops},
>>> +#ifdef CONFIG_DRM_AMD_DC_HDCP
>>> +        {"hdcp_sink_capability", &hdcp_sink_capability_fops},
>>> +#endif
>>>           {"sdp_message", &sdp_message_fops},
>>>           {"aux_dpcd_address", &dp_dpcd_address_debugfs_fops},
>>>           {"aux_dpcd_size", &dp_dpcd_size_debugfs_fops},
>>>           {"aux_dpcd_data", &dp_dpcd_data_debugfs_fops}
>>>   };
>>>   +#ifdef CONFIG_DRM_AMD_DC_HDCP
>>> +static const struct {
>>> +    char *name;
>>> +    const struct file_operations *fops;
>>> +} hdmi_debugfs_entries[] = {
>>> +        {"hdcp_sink_capability", &hdcp_sink_capability_fops}
>>> +};
>>> +#endif
>>>   /*
>>>    * Force YUV420 output if available from the given mode
>>>    */
>>> @@ -1066,6 +1118,15 @@ void connector_debugfs_init(struct
>>> amdgpu_dm_connector *connector)
>>>       debugfs_create_file_unsafe("force_yuv420_output", 0644, dir,
>>> connector,
>>>                      &force_yuv420_output_fops);
>>>   +#ifdef CONFIG_DRM_AMD_DC_HDCP
>>> +    if (connector->base.connector_type == DRM_MODE_CONNECTOR_HDMIA) {
>> Your patch description mentions DP and HDMI but here you're only
>> creating it for HDMI. Should we create it for all HDCP-capable signal
>> types, i.e. DP and HDMI?
>>
>> Harry
> 
> There is a loop above that is called for dp_debugfs_entries[]. I have
> added the HDCP debugfs to that struct so no need to recreate the loop.
> 

I see it now. Thanks.

Patch is
Reviewed-by: Harry Wentland <harry.wentland at amd.com>

Harry

> Bhawan
> 
>>> +        for (i = 0; i < ARRAY_SIZE(hdmi_debugfs_entries); i++) {
>>> +            debugfs_create_file(hdmi_debugfs_entries[i].name,
>>> +                        0644, dir, connector,
>>> +                        hdmi_debugfs_entries[i].fops);
>>> +        }
>>> +    }
>>> +#endif
>>>   }
>>>     /*
>>>