On Wed, 2018-12-05 at 14:57 -0800, Manasi Navare wrote:
> DSC can be supported per DP connector. This patch adds a per connector
> debugfs node to expose DSC support capability by the kernel.
> The same node can be used from userspace to force DSC enable.
>
> force_dsc_en written through this debugfs node is used to force
> DSC even for lower resolutions.
>
> Credits to Ville Syrjala for suggesting the proper locks to be used
> and to Lyude Paul for explaining how to use them in this context
>
> v7:
> * Get crtc, crtc_state from connector atomic state
> and add proper locks and backoff (Ville, Chris Wilson, Lyude)
> (Suggested-by: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx>)
> * Use %zu for printing size_t variable (Lyude)
> v6:
> * Read fec_capable only for non edp (Manasi)
> v5:
> * Name it dsc sink support and also add
> fec support in the same node (Ville)
> v4:
> * Add missed connector_status check (Manasi)
> * Create i915_dsc_support node only for Gen >=10 (manasi)
> * Access intel_dp->dsc_dpcd only if its not NULL (Manasi)
> v3:
> * Combine Force_dsc_en with this patch (Ville)
> v2:
> * Use kstrtobool_from_user to avoid explicit error checking (Lyude)
> * Rebase on drm-tip (Manasi)
>
> Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx>
> Cc: Anusha Srivatsa <anusha.srivatsa@xxxxxxxxx>
> Cc: Lyude Paul <lyude@xxxxxxxxxx>
> Signed-off-by: Manasi Navare <manasi.d.navare@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 107 ++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/intel_dp.c | 3 +-
> drivers/gpu/drm/i915/intel_drv.h | 3 +
> 3 files changed, 112 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
> b/drivers/gpu/drm/i915/i915_debugfs.c
> index 129b9a6f8309..58f6636fffea 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -5086,6 +5086,106 @@ static int i915_hdcp_sink_capability_show(struct
> seq_file *m, void *data)
> }
> DEFINE_SHOW_ATTRIBUTE(i915_hdcp_sink_capability);
>
> +static int i915_dsc_fec_support_show(struct seq_file *m, void *data)
> +{
> + struct drm_connector *connector = m->private;
> + struct drm_device *dev = connector->dev;
> + struct drm_crtc *crtc;
> + struct intel_dp *intel_dp;
> + struct drm_modeset_acquire_ctx ctx;
> + struct intel_crtc_state *crtc_state = NULL;
> + int ret = 0;
> + bool try_again = false;
> +
> + drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
> +
> + do {
> + ret = drm_modeset_lock(&dev->mode_config.connection_mutex,
> + &ctx);
> + if (ret) {
> + ret = -EINTR;
> + break;
> + }
> + crtc = connector->state->crtc;
> + if (connector->status != connector_status_connected || !crtc)
> {
> + ret = -ENODEV;
> + break;
> + }
> + ret = drm_modeset_lock(&crtc->mutex, &ctx);
> + if (ret == -EDEADLK) {
> + ret = drm_modeset_backoff(&ctx);
> + if (!ret) {
> + try_again = true;
> + continue;
> + }
> + break;
> + }
> + if (ret)
> + break;
Maybe maybe make this:
} else if (ret) {
break;
}
Just for clarity. With that change:
Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
> +
> + intel_dp = enc_to_intel_dp(&intel_attached_encoder(connector)-
> >base);
> + crtc_state = to_intel_crtc_state(crtc->state);
> + seq_printf(m, "DSC_Enabled: %s\n",
> + yesno(crtc_state->dsc_params.compression_enable));
> + if (intel_dp->dsc_dpcd)
> + seq_printf(m, "DSC_Sink_Support: %s\n",
> + yesno(drm_dp_sink_supports_dsc(intel_dp-
> >dsc_dpcd)));
> + if (!intel_dp_is_edp(intel_dp))
> + seq_printf(m, "FEC_Sink_Support: %s\n",
> + yesno(drm_dp_sink_supports_fec(intel_dp-
> >fec_capable)));
> + } while (try_again);
> +
> + drm_modeset_drop_locks(&ctx);
> + drm_modeset_acquire_fini(&ctx);
> +
> + return ret;
> +}
> +
> +static ssize_t i915_dsc_fec_support_write(struct file *file,
> + const char __user *ubuf,
> + size_t len, loff_t *offp)
> +{
> + bool dsc_enable = false;
> + int ret;
> + struct drm_connector *connector =
> + ((struct seq_file *)file->private_data)->private;
> + struct intel_encoder *encoder = intel_attached_encoder(connector);
> + struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
> +
> + if (len == 0)
> + return 0;
> +
> + DRM_DEBUG_DRIVER("Copied %zu bytes from user to force DSC\n",
> + len);
> +
> + ret = kstrtobool_from_user(ubuf, len, &dsc_enable);
> + if (ret < 0)
> + return ret;
> +
> + DRM_DEBUG_DRIVER("Got %s for DSC Enable\n",
> + (dsc_enable) ? "true" : "false");
> + intel_dp->force_dsc_en = dsc_enable;
> +
> + *offp += len;
> + return len;
> +}
> +
> +static int i915_dsc_fec_support_open(struct inode *inode,
> + struct file *file)
> +{
> + return single_open(file, i915_dsc_fec_support_show,
> + inode->i_private);
> +}
> +
> +static const struct file_operations i915_dsc_fec_support_fops = {
> + .owner = THIS_MODULE,
> + .open = i915_dsc_fec_support_open,
> + .read = seq_read,
> + .llseek = seq_lseek,
> + .release = single_release,
> + .write = i915_dsc_fec_support_write
> +};
> +
> /**
> * i915_debugfs_connector_add - add i915 specific connector debugfs files
> * @connector: pointer to a registered drm_connector
> @@ -5098,6 +5198,7 @@ DEFINE_SHOW_ATTRIBUTE(i915_hdcp_sink_capability);
> int i915_debugfs_connector_add(struct drm_connector *connector)
> {
> struct dentry *root = connector->debugfs_entry;
> + struct drm_i915_private *dev_priv = to_i915(connector->dev);
>
> /* The connector must have been registered beforehands. */
> if (!root)
> @@ -5122,5 +5223,11 @@ int i915_debugfs_connector_add(struct drm_connector
> *connector)
> connector,
> &i915_hdcp_sink_capability_fops);
> }
>
> + if (INTEL_GEN(dev_priv) >= 10 &&
> + (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
> + connector->connector_type == DRM_MODE_CONNECTOR_eDP))
> + debugfs_create_file("i915_dsc_fec_support", S_IRUGO, root,
> + connector, &i915_dsc_fec_support_fops);
> +
> return 0;
> }
> diff --git a/drivers/gpu/drm/i915/intel_dp.c
> b/drivers/gpu/drm/i915/intel_dp.c
> index a6907a1761ab..2e3097cae277 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -2051,7 +2051,8 @@ intel_dp_compute_link_config(struct intel_encoder
> *encoder,
> &limits);
>
> /* enable compression if the mode doesn't fit available BW */
> - if (!ret) {
> + DRM_DEBUG_KMS("Force DSC en = %d\n", intel_dp->force_dsc_en);
> + if (!ret || intel_dp->force_dsc_en) {
> if (!intel_dp_dsc_compute_config(intel_dp, pipe_config,
> conn_state, &limits))
> return false;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h
> b/drivers/gpu/drm/i915/intel_drv.h
> index f94a04b4ad87..0cedce438433 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1209,6 +1209,9 @@ struct intel_dp {
>
> /* Displayport compliance testing */
> struct intel_dp_compliance compliance;
> +
> + /* Display stream compression testing */
> + bool force_dsc_en;
> };
>
> enum lspcon_vendor {
--
Cheers,
Lyude Paul
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