> -----Original Message-----
> From: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> Sent: Tuesday, February 13, 2024 8:26 PM
> To: Shankar, Uma <uma.shankar@xxxxxxxxx>
> Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; Lisovskiy, Stanislav
> <stanislav.lisovskiy@xxxxxxxxx>; ville.syrjala@xxxxxxxxxxxxxxx;
> jani.nikula@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH] drm/i915: Add bigjoiner force enable option to debugfs
>
> On Mon, Feb 12, 2024 at 06:20:11PM +0530, Uma Shankar wrote:
> > From: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> >
> > 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
> >
> > v7: - Move bigjoiner force option to intel_connector(Ville Syrjälä)
> > - Use DEFINE_SHOW_STORE_ATTRIBUTE instead of defining fops
> > manually.(Ville Syrjälä)
> >
> > v8: - Pass intel_connector to debugfs_create_file, instead of drm_connector.
> > (Jani Nikula)
> >
> > Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
>
> please remind to sign-off when sending someone else's patch.
Oh yeah, sorry missed it. Was filling in for Stan while he was OOO.
@Lisovskiy, Stanislav Please address rest of the comments raised by Rodrigo.
Regards,
Uma Shankar
> > ---
> > .../drm/i915/display/intel_display_debugfs.c | 47 +++++++++++++++++++
> > .../drm/i915/display/intel_display_types.h | 2 +
> > drivers/gpu/drm/i915/display/intel_dp.c | 4 +-
> > 3 files changed, 52 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 6f2d13c8ccf7..a962b48bcf13 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > @@ -1391,6 +1391,20 @@ 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 drm_crtc *crtc;
> > +
> > + crtc = connector->base.state->crtc;
> > + if (connector->base.status != connector_status_connected || !crtc)
> > + return -ENODEV;
> > +
> > + seq_printf(m, "Bigjoiner enable: %d\n",
> > +connector->force_bigjoiner_enable);
>
> probably better with a yes_or_no string?
>
> > +
> > + return 0;
> > +}
> > +
> > static ssize_t i915_dsc_output_format_write(struct file *file,
> > const char __user *ubuf,
> > size_t len, loff_t *offp)
> > @@ -1412,6 +1426,30 @@ static ssize_t i915_dsc_output_format_write(struct
> file *file,
> > return len;
> > }
> >
> > +static ssize_t i915_bigjoiner_enable_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 drm_crtc *crtc;
> > + bool bigjoiner_en = 0;
> > + int ret;
> > +
> > + crtc = connector->base.state->crtc;
> > + if (connector->base.status != connector_status_connected || !crtc)
> > + return -ENODEV;
> > +
> > + ret = kstrtobool_from_user(ubuf, len, &bigjoiner_en);
> > + if (ret < 0)
> > + return ret;
> > +
> > + connector->force_bigjoiner_enable = bigjoiner_en;
> > + *offp += len;
> > +
> > + return len;
> > +}
> > +
> > static int i915_dsc_output_format_open(struct inode *inode,
> > struct file *file)
> > {
> > @@ -1505,6 +1543,8 @@ static const struct file_operations
> i915_dsc_fractional_bpp_fops = {
> > .write = i915_dsc_fractional_bpp_write };
> >
> > +DEFINE_SHOW_STORE_ATTRIBUTE(i915_bigjoiner_enable);
>
> I don't believe this macro here is using the defined _show function, but maybe I'm
> not following that very well since this macro is not widely used.
>
> What about using DEFINE_SIMPLE_ATTRIBUTE instead?
>
> > +
> > /*
> > * Returns the Current CRTC's bpc.
> > * Example usage: cat /sys/kernel/debug/dri/0/crtc-0/i915_current_bpc
> > @@ -1586,6 +1626,13 @@ 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)) {
>
> I wish we had a simpler check, but I couldn't find. :/
>
> > + debugfs_create_file("i915_bigjoiner_force_enable", 0644, root,
> > + connector, &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 01eb6e4e6049..0d4012097db1 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -626,6 +626,8 @@ struct intel_connector {
> >
> > struct intel_dp *mst_port;
> >
> > + bool force_bigjoiner_enable;
> > +
> > struct {
> > struct drm_dp_aux *dsc_decompression_aux;
> > u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE];
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> > b/drivers/gpu/drm/i915/display/intel_dp.c
> > index 5045c34a16be..217196196e50 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > @@ -1205,11 +1205,13 @@ bool intel_dp_need_bigjoiner(struct intel_dp
> *intel_dp,
> > int hdisplay, int clock)
> > {
> > struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> > + struct intel_connector *connector = intel_dp->attached_connector;
> >
> > 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 ||
> > + connector->force_bigjoiner_enable;
>
> I'm just not comfortable with the magic _show of that macro and would prefer a
> more simple and straight forward and widely used version.
>
> Other then that everything else looks good to me.
>
> Thanks,
> Rodrigo.
>
> > }
> >
> > static enum drm_mode_status
> > --
> > 2.42.0
> >
