Thanks Stan for the patch.
I agree that since by forcing big joiner enable we are simulating a
higher mode/pixel clock on a connector, this should be a per connector
debugfs except for edp that can be exposed.
Manasi
On Mon, Jan 15, 2024 at 12:57 AM Lisovskiy, Stanislav
<stanislav.lisovskiy@xxxxxxxxx> wrote:
>
> On Fri, Jan 12, 2024 at 06:25:05PM +0200, Ville Syrjälä wrote:
> > On Mon, Jan 08, 2024 at 02:07:23PM +0200, Stanislav Lisovskiy wrote:
> > > For validation purposes, it might be useful to be able to
> > > force Bigjoiner mode, even if current dotclock/resolution
> > > do not require that.
> > > Lets add such to option to debugfs.
> > >
> > > v2: - Apparently intel_dp_need_bigjoiner can't be used, when
> > > debugfs entry is created so lets just check manually
> > > the DISPLAY_VER.
> > >
> > > v3: - Switch to intel_connector from drm_connector(Jani Nikula)
> > > - Remove redundant modeset lock(Jani Nikula)
> > > - Use kstrtobool_from_user for boolean value(Jani Nikula)
> > >
> > > v4: - Apply the changes to proper function(Jani Nikula)
> > >
> > > v5: - Removed unnecessary check from i915_bigjoiner_enable_show
> > > (Ville Syrjälä)
> > > - Added eDP connector check to intel_connector_debugfs_add
> > > (Ville Syrjälä)
> > > - Removed debug message in order to prevent dmesg flooding
> > > (Ville Syrjälä)
> > >
> > > v6: - Assume now always that m->private is intel_connector
> > > - Fixed other similar conflicts
> > >
> > > Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> > > ---
> > > .../drm/i915/display/intel_display_debugfs.c | 59 +++++++++++++++++++
> > > .../drm/i915/display/intel_display_types.h | 2 +
> > > drivers/gpu/drm/i915/display/intel_dp.c | 3 +-
> > > 3 files changed, 63 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > index d951edb366871..353e71b4e1db2 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > > @@ -1413,6 +1413,22 @@ out: drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
> > > return ret;
> > > }
> > >
> > > +static int i915_bigjoiner_enable_show(struct seq_file *m, void *data)
> > > +{
> > > + struct intel_connector *connector = m->private;
> > > + struct intel_encoder *encoder = intel_attached_encoder(connector);
> > > + struct intel_dp *intel_dp;
> > > +
> > > + if (!encoder)
> > > + return -ENODEV;
> > > +
> > > + intel_dp = enc_to_intel_dp(encoder);
> > > +
> > > + seq_printf(m, "Bigjoiner enable: %d\n", intel_dp->force_bigjoiner_enable);
> >
> > So it's a per-connector debugfs knob but we track it in the
> > SST DP encoder? That's rather odd, and not going to work for MST.
>
> I guess you mean, I should move it to the connector instead, makes sense.
>
> >
> > > +
> > > + return 0;
> > > +}
> > > +
> > > static ssize_t i915_dsc_output_format_write(struct file *file,
> > > const char __user *ubuf,
> > > size_t len, loff_t *offp)
> > > @@ -1434,12 +1450,39 @@ static ssize_t i915_dsc_output_format_write(struct file *file,
> > > return len;
> > > }
> > >
> > > +static ssize_t i915_bigjoiner_enable_fops_write(struct file *file,
> > > + const char __user *ubuf,
> > > + size_t len, loff_t *offp)
> > > +{
> > > + struct seq_file *m = file->private_data;
> > > + struct intel_connector *connector = m->private;
> > > + struct intel_encoder *encoder = intel_attached_encoder(connector);
> > > + struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> > > + bool bigjoiner_en = 0;
> > > + int ret;
> > > +
> > > + ret = kstrtobool_from_user(ubuf, len, &bigjoiner_en);
> > > + if (ret < 0)
> > > + return ret;
> > > +
> > > + intel_dp->force_bigjoiner_enable = bigjoiner_en;
> > > + *offp += len;
> > > +
> > > + return len;
> > > +}
> > > +
> > > static int i915_dsc_output_format_open(struct inode *inode,
> > > struct file *file)
> > > {
> > > return single_open(file, i915_dsc_output_format_show, inode->i_private);
> > > }
> > >
> > > +static int i915_bigjoiner_enable_open(struct inode *inode,
> > > + struct file *file)
> > > +{
> > > + return single_open(file, i915_bigjoiner_enable_show, inode->i_private);
> > > +}
> > > +
> > > static const struct file_operations i915_dsc_output_format_fops = {
> > > .owner = THIS_MODULE,
> > > .open = i915_dsc_output_format_open,
> > > @@ -1527,6 +1570,15 @@ static const struct file_operations i915_dsc_fractional_bpp_fops = {
> > > .write = i915_dsc_fractional_bpp_write
> > > };
> > >
> > > +static const struct file_operations i915_bigjoiner_enable_fops = {
> > > + .owner = THIS_MODULE,
> > > + .open = i915_bigjoiner_enable_open,
> > > + .read = seq_read,
> > > + .llseek = seq_lseek,
> > > + .release = single_release,
> > > + .write = i915_bigjoiner_enable_fops_write
> > > +};
> >
> > Why are we implementing this long-hand for a simple boolean flag?
>
> Will check, thought thats the only way..
>
> >
> > > +
> > > /*
> > > * Returns the Current CRTC's bpc.
> > > * Example usage: cat /sys/kernel/debug/dri/0/crtc-0/i915_current_bpc
> > > @@ -1608,6 +1660,13 @@ void intel_connector_debugfs_add(struct intel_connector *connector)
> > > connector, &i915_dsc_fractional_bpp_fops);
> > > }
> > >
> > > + if (DISPLAY_VER(i915) >= 11 &&
> > > + (connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
> > > + connector_type == DRM_MODE_CONNECTOR_eDP)) {
> > > + debugfs_create_file("i915_bigjoiner_force_enable", 0644, root,
> > > + &connector->base, &i915_bigjoiner_enable_fops);
> > > + }
> > > +
> > > if (connector_type == DRM_MODE_CONNECTOR_DSI ||
> > > connector_type == DRM_MODE_CONNECTOR_eDP ||
> > > connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > index b9b9d9f2bc0ba..e4c5a44dd02f5 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > @@ -1768,6 +1768,8 @@ struct intel_dp {
> > > bool is_mst;
> > > int active_mst_links;
> > >
> > > + bool force_bigjoiner_enable;
> > > +
> > > /* connector directly attached - won't be use for modeset in mst world */
> > > struct intel_connector *attached_connector;
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > index 9ff0cbd9c0df5..525ab926582d5 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > @@ -1208,7 +1208,8 @@ bool intel_dp_need_bigjoiner(struct intel_dp *intel_dp,
> > > if (!intel_dp_can_bigjoiner(intel_dp))
> > > return false;
> > >
> > > - return clock > i915->max_dotclk_freq || hdisplay > 5120;
> > > + return clock > i915->max_dotclk_freq || hdisplay > 5120 ||
> > > + intel_dp->force_bigjoiner_enable;
> > > }
> > >
> > > static enum drm_mode_status
> > > --
> > > 2.37.3
> >
> > --
> > Ville Syrjälä
> > Intel
