On Wed, 13 Sep 2023, Mitul Golani <mitulkumar.ajitkumar.golani@xxxxxxxxx> wrote: > From: Swati Sharma <swati2.sharma@xxxxxxxxx> > > DSC_Sink_BPP_Precision entry is added to i915_dsc_fec_support_show > to depict sink's precision. > Also, new debugfs entry is created to enforce fractional bpp. > If Force_DSC_Fractional_BPP_en is set then while iterating over > output bpp with fractional step size we will continue if output_bpp is > computed as integer. With this approach, we will be able to validate > DSC with fractional bpp. > > v2: > Add drm_modeset_unlock to new line(Suraj) > > Signed-off-by: Swati Sharma <swati2.sharma@xxxxxxxxx> > Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx> > Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@xxxxxxxxx> > Reviewed-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx> > --- > .../drm/i915/display/intel_display_debugfs.c | 83 +++++++++++++++++++ > .../drm/i915/display/intel_display_types.h | 1 + > 2 files changed, 84 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c > index f05b52381a83..776ab96def1f 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c > +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c > @@ -1244,6 +1244,8 @@ static int i915_dsc_fec_support_show(struct seq_file *m, void *data) > DP_DSC_YCbCr420_Native)), > str_yes_no(drm_dp_dsc_sink_supports_format(intel_dp->dsc_dpcd, > DP_DSC_YCbCr444))); > + seq_printf(m, "DSC_Sink_BPP_Precision: %d\n", > + drm_dp_dsc_sink_bpp_incr(intel_dp->dsc_dpcd)); > seq_printf(m, "Force_DSC_Enable: %s\n", > str_yes_no(intel_dp->force_dsc_en)); > if (!intel_dp_is_edp(intel_dp)) > @@ -1436,6 +1438,84 @@ static const struct file_operations i915_dsc_output_format_fops = { > .write = i915_dsc_output_format_write > }; > > +static int i915_dsc_fractional_bpp_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 intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector)); > + int ret; > + > + if (!encoder) > + return -ENODEV; > + > + ret = drm_modeset_lock_single_interruptible(&dev->mode_config.connection_mutex); > + if (ret) > + return ret; > + > + crtc = connector->state->crtc; > + if (connector->status != connector_status_connected || !crtc) { > + ret = -ENODEV; > + goto out; > + } > + > + intel_dp = intel_attached_dp(to_intel_connector(connector)); > + seq_printf(m, "Force_DSC_Fractional_BPP_Enable: %s\n", > + str_yes_no(intel_dp->force_dsc_fractional_bpp_en)); Why "Force_DSC_Fractional_BPP_Enable" in the output? Usually debugfs files, like sysfs files, for stuff like this should be attributes, one thing per file. Why print a long name for it, if the name of the debugfs file is the name of the attribute? And even if you print it for humans, why the underscores? > + > +out: > + drm_modeset_unlock(&dev->mode_config.connection_mutex); > + > + return ret; > +} > + > +static ssize_t i915_dsc_fractional_bpp_write(struct file *file, > + const char __user *ubuf, > + size_t len, loff_t *offp) > +{ > + struct drm_connector *connector = > + ((struct seq_file *)file->private_data)->private; I know this is copy-pasted from elsewhere, but really it's nicer to avoid the cast, and copy-paste from the places that get this right: struct seq_file *m = file->private_data; struct drm_connector *connector = m->private; > + struct intel_encoder *encoder = intel_attached_encoder(to_intel_connector(connector)); > + struct drm_i915_private *i915 = to_i915(encoder->base.dev); > + struct intel_dp *intel_dp = enc_to_intel_dp(encoder); > + bool dsc_fractional_bpp_enable = false; > + int ret; > + > + if (len == 0) > + return 0; kstrtobool_from_user() has this covered. > + > + drm_dbg(&i915->drm, > + "Copied %zu bytes from user to force fractional bpp for DSC\n", len); That's useless. > + > + ret = kstrtobool_from_user(ubuf, len, &dsc_fractional_bpp_enable); > + if (ret < 0) > + return ret; > + > + drm_dbg(&i915->drm, "Got %s for DSC Fractional BPP Enable\n", > + (dsc_fractional_bpp_enable) ? "true" : "false"); Is this useful? > + intel_dp->force_dsc_fractional_bpp_en = dsc_fractional_bpp_enable; > + > + *offp += len; > + > + return len; > +} > + > +static int i915_dsc_fractional_bpp_open(struct inode *inode, > + struct file *file) > +{ > + return single_open(file, i915_dsc_fractional_bpp_show, inode->i_private); > +} > + > +static const struct file_operations i915_dsc_fractional_bpp_fops = { > + .owner = THIS_MODULE, > + .open = i915_dsc_fractional_bpp_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > + .write = i915_dsc_fractional_bpp_write > +}; > + > /* > * Returns the Current CRTC's bpc. > * Example usage: cat /sys/kernel/debug/dri/0/crtc-0/i915_current_bpc > @@ -1513,6 +1593,9 @@ void intel_connector_debugfs_add(struct intel_connector *intel_connector) > > debugfs_create_file("i915_dsc_output_format", 0644, root, > connector, &i915_dsc_output_format_fops); > + > + debugfs_create_file("i915_dsc_fractional_bpp", 0644, root, > + connector, &i915_dsc_fractional_bpp_fops); > } > > if (connector->connector_type == DRM_MODE_CONNECTOR_DSI || > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > index 69bcabec4a29..27b31cb4c7b4 100644 > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > @@ -1797,6 +1797,7 @@ struct intel_dp { > /* Display stream compression testing */ > bool force_dsc_en; > int force_dsc_output_format; > + bool force_dsc_fractional_bpp_en; > int force_dsc_bpc; > > bool hobl_failed; -- Jani Nikula, Intel