On Fri, Sep 06, 2024 at 05:46:11PM +0300, Ville Syrjälä wrote:
> On Fri, Sep 06, 2024 at 06:27:54PM +0530, Ankit Nautiyal wrote:
> > At the moment, the debugfs for joiner allows only to force enable/disable
> > pipe joiner for 2 pipes. Modify it to force join 'n' number of pipes,
> > where n is a valid pipe joiner configuration.
> > This will help in case of ultra joiner where 4 pipes are joined.
> >
> > v2:
> > -Fix commit message to state that only valid joiner config can be
> > forced. (Suraj)
> > -Rename the identifiers to have INTEL_BIG/NONE_JOINER_PIPES. (Suraj)
> >
> > Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
> > ---
> > .../drm/i915/display/intel_display_debugfs.c | 71 ++++++++++++++++++-
> > .../drm/i915/display/intel_display_types.h | 8 ++-
> > drivers/gpu/drm/i915/display/intel_dp.c | 2 +-
> > 3 files changed, 77 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > index 830b9eb60976..0ef573afd8a1 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> > @@ -1504,6 +1504,73 @@ static int intel_crtc_pipe_show(struct seq_file *m, void *unused)
> > }
> > DEFINE_SHOW_ATTRIBUTE(intel_crtc_pipe);
> >
> > +static int i915_joiner_show(struct seq_file *m, void *data)
> > +{
> > + struct intel_connector *connector = m->private;
> > + struct drm_i915_private *i915 = to_i915(connector->base.dev);
> > + int ret;
> > +
> > + ret = drm_modeset_lock_single_interruptible(&i915->drm.mode_config.connection_mutex);
> > + if (ret)
> > + return ret;
>
> What does that lock do for us?
>
> > +
> > + seq_printf(m, "Force_joined_pipes: %d\n", connector->force_joined_pipes);
>
> This should just be thae bare number. Adding other junk in there just
> complicates matters if anyone has to parse this.
>
> > +
> > + drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
> > +
> > + return ret;
> > +}
> > +
> > +static ssize_t i915_joiner_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_i915_private *i915 = to_i915(connector->base.dev);
> > + int force_join_pipes = 0;
> > + int ret;
> > +
> > + if (len == 0)
> > + return 0;
> > +
> > + drm_dbg(&i915->drm,
> > + "Copied %zu bytes from user to force joiner\n", len);
>
> Leftover debug junk.
>
> > +
> > + ret = kstrtoint_from_user(ubuf, len, 0, &force_join_pipes);
> > + if (ret < 0)
> > + return ret;
> > +
> > + drm_dbg(&i915->drm, "Got %d for force joining pipes\n", force_join_pipes);
>
> More.
>
> > +
> > + if (force_join_pipes < INTEL_NONE_JOINER_PIPES ||
> > + force_join_pipes >= INTEL_INVALID_JOINER_PIPES) {
> > + drm_dbg(&i915->drm, "Ignoring Invalid num of pipes %d for force joining\n",
> > + force_join_pipes);
> > + connector->force_joined_pipes = INTEL_NONE_JOINER_PIPES;
> > + } else {
> > + connector->force_joined_pipes = force_join_pipes;
> > + }
>
> I think just something like
> switch (num_pipes) {
> case 0: /* or should 1 be the default? */
I suppose both 0 and 1 should be accepted. 0==not forced, 1==forced to
exactly one pipe (ie. no joiner despite what the automagic logic
is saying).
> case 2:
> case 4:
> break;
> default:
> bad;
> }
>
> should do for validation.
>
--
Ville Syrjälä
Intel
