Re: [PATCH 09/10] drm/i915: Add debugfs entries for reading out DPCD DSC and FEC.

Jani Nikula
2019-08-23T10:19:12Z

On Wed, 21 Aug 2019, Maarten Lankhorst <maarten.lankhorst@linux.intel.com> wrote:
> Dump the DSC and FEC in i915_dpcd as well. This is useful when
> debugging the link caps.

I thought we were going to get rid of this particular debugfs file
altogether ages ago. You can dump the DPCD using
CONFIG_DRM_DP_AUX_CHARDEV=y and dd on /dev/drm_dp_auxN.

BR,
Jani.

>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 610bc9b5d740..c2f15de07427 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -4396,8 +4396,10 @@ struct dpcd_block {
>
> static const struct dpcd_block i915_dpcd_debug[] = {
> { .offset = DP_DPCD_REV, .size = DP_RECEIVER_CAP_SIZE },
> + { .offset = DP_DSC_SUPPORT, .end = DP_DSC_BITS_PER_PIXEL_INC },
> { .offset = DP_PSR_SUPPORT, .end = DP_PSR_CAPS },
> { .offset = DP_DOWNSTREAM_PORT_0, .size = 16 },
> + { .offset = DP_FEC_CAPABILITY },
> { .offset = DP_LINK_BW_SET, .end = DP_EDP_CONFIGURATION_SET },
> { .offset = DP_SINK_COUNT, .end = DP_ADJUST_REQUEST_LANE2_3 },
> { .offset = DP_SET_POWER },

--
Jani Nikula, Intel Open Source Graphics Center