Re: [PATCH] drm: sysfs: Add to get current mode

[Huang Jiachai]

Hi Daniel

在 2020/8/5 17:36, Daniel Vetter 写道:
> On Wed, Aug 5, 2020 at 10:37 AM Sandy Huang <hjc@xxxxxxxxxxxxxx> wrote:
> > add this node to get the current true mode.
> >
> > Signed-off-by: Sandy Huang <hjc@xxxxxxxxxxxxxx>
> Uh what's this for? Since it's sysfs, I guess there's something
> parsing this, which means we'd kinda need to have that piece too.
>
> If it's just for debugging purposes, then we already have this
> information in debugfs, together with everything else that's in the
> atomic modeset state.
> -Daniel

yes, this is just for debug;

and i get the information what i need from cat 
/sys/kernel/debug/dri/0/state, thanks.

> > ---
> >   drivers/gpu/drm/drm_sysfs.c | 30 ++++++++++++++++++++++++++++++
> >   1 file changed, 30 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
> > index 939f0032aab1..f39bcd34853b 100644
> > --- a/drivers/gpu/drm/drm_sysfs.c
> > +++ b/drivers/gpu/drm/drm_sysfs.c
> > @@ -19,6 +19,7 @@
> >   #include <linux/slab.h>
> >
> >   #include <drm/drm_connector.h>
> > +#include <drm/drm_crtc.h>
> >   #include <drm/drm_device.h>
> >   #include <drm/drm_file.h>
> >   #include <drm/drm_modes.h>
> > @@ -236,16 +237,45 @@ static ssize_t modes_show(struct device *device,
> >          return written;
> >   }
> >
> > +static ssize_t current_mode_show(struct device *device,
> > +                     struct device_attribute *attr,
> > +                     char *buf)
> > +{
> > +       struct drm_connector *connector = to_drm_connector(device);
> > +       struct drm_display_mode *mode;
> > +       struct drm_crtc_state *crtc_state;
> > +       bool interlaced;
> > +       int written = 0;
> > +
> > +       if (!connector->state || !connector->state->crtc)
> > +               return written;
> > +
> > +       crtc_state = connector->state->crtc->state;
> > +       if (!crtc_state)
> > +               return written;
> > +
> > +       mode = &crtc_state->mode;
> > +
> > +       interlaced = !!(mode->flags & DRM_MODE_FLAG_INTERLACE);
> > +       written += snprintf(buf + written, PAGE_SIZE - written, "%dx%d%s%d\n",
> > +                           mode->hdisplay, mode->vdisplay,
> > +                           interlaced ? "i" : "p", drm_mode_vrefresh(mode));
> > +
> > +       return written;
> > +}
> > +
> >   static DEVICE_ATTR_RW(status);
> >   static DEVICE_ATTR_RO(enabled);
> >   static DEVICE_ATTR_RO(dpms);
> >   static DEVICE_ATTR_RO(modes);
> > +static DEVICE_ATTR_RO(current_mode);
> >
> >   static struct attribute *connector_dev_attrs[] = {
> >          &dev_attr_status.attr,
> >          &dev_attr_enabled.attr,
> >          &dev_attr_dpms.attr,
> >          &dev_attr_modes.attr,
> > +       &dev_attr_current_mode.attr,
> >          NULL
> >   };
> >
> > --
> > 2.17.1
--
Best Regard

黄家钗
Sandy Huang
Addr: 福州市鼓楼区铜盘路软件大道89号福州软件园A区21号楼(350003)
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